Tag: #Biology

Introduction

Through the process of reproduction, an organism gives rise to offspring that are biologically related to the organism.

Reproduction enables and ensures species continuity generation after generation.

There are essentially two types of reproduction:

• Sexual reproduction
• Asexual reproduction

Asexual reproduction

The simplest type of reproduction is asexual reproduction, which doesn’t involve gamete creation, meiosis, or fertilization. These types of reproduction only need one parent, and the resulting individuals, or clones, are genetically identical. Asexual reproduction is also referred to as clonal propagation. Animals can reproduce asexually through a variety of mechanisms, including Binary Fusion, Fragmentation, Budding, Parthenogenesis, Gemmules, Regeneration, etc.

Features of asexual reproduction

• A single parent is involved.
• Neither fertilization nor gamete formation takes place.
• This reproduction process happens in a relatively short amount of time.
• The organisms multiply and grow swiftly.
• The offsprings are similar genetically.

Types of asexual reproduction

• Binary Fission

• • Bacteria and amoebas are the two main species that utilize this method of reproduction.
  • This occurs when the DNA of the parent bacteria breaks into two fragments, each of which has its DNA.
  • As a result, the parent cell splits into two identical daughter cells.

• Fragmentation:

• • In this method of asexual reproduction, the parent organism is divided into multiple fragments, each of which develops into a new organism.
  • This method of reproduction is mostly seen in starfish. For instance, the arm can give birth to an entirely new organism.

• Gemmules:
• • • In this kind, the parents release a highly developed mass of cells, which eventually give rise to offspring.
    • The development of these gemmules occurs when parents face unfavorable environmental conditions.

• Parthenogenesis: 

• • In this type of asexual reproduction, the female organism produces eggs without fertilization, These eggs give birth to offspring.
  • Examples are lizards, certain fish, and insects.
• Regeneration:
• • Regeneration is the replacement of a missing part or the growth of an organism’s entire body from a small portion (morphallaxis) (epimorphosis).
  • It is primarily found in planaria, sponges, amoebas, and many other organisms.
  • There are 2 types of regeneration-
  • Reparative regeneration: Only some kinds of damaged tissues are capable of regeneration.
  • Restorative regeneration: In this, severed body parts can be restored or grown into a complete body.

• Budding:

• • In this type of reproduction, the child grows on the parent’s body much like a bud. Echinodermata and Hydra are two well-known examples of this type of asexual reproduction.
  • Here, the bud begins to live independently after separating from the parent plant.
  • There are two types of bidding-
  • Exogenous or External budding: A bud forms on the exterior of the body in this sort of budding. This growing bud learns to live alone after becoming separated from its parent. Newly formed buds have two choices: they can remain attached to their parents or they can detach and create their offspring.
  • Endogenous or internal budding: In a few marine sponges, buds form inside the bodies of the sponge parents (e.g. Spongilla).

Advantages of asexual reproduction

• An organism can give birth to a large number of offspring, swiftly increasing that species’ population.
• There is no need for another parent organism since asexual reproduction involves only one parent.
• Animals can reproduce asexually without their gametes fusing, thus gamete formation is not required.
• Because mating is not required, less energy is used.
• Sexual reproduction is outpaced by the offspring’s rate of asexual reproduction.

Disadvantages of asexual reproduction

• Population growth is accelerating due to asexual reproduction, therefore difficult to control the population of only one species.
• They compete with one another since both species rely on the same habitat for survival.
• The atmosphere must be conducive for both the parent and the offspring.
• Children are biologically identical to the single-parent organism.
• Genetic variety does not exist in this type of reproduction.

Summary

In conclusion, asexual reproduction is a sort of reproduction in which an offspring is born from a single parent. Since the newly reproduced organisms are physically and genetically similar, they are genetic clones of their parents. Asexual reproduction is present in multicellular and unicellular animals. During this reproduction,  gamete fusion does not take place. There are various types of asexual reproduction- such as fragmentation, binary fission, regeneration, etc.

Frequently Asked Questions

1. Different types of binary fission.
Ans: There are 4 types of binary fission-

• Simple binary fission: This fission can occur through any organism’s plane. Eg- Amoeba.
• Longitude binary fission: It is also referred to as longitudinal binary fission since it takes place along the longitudinal plane. Longitude binary fission is a process that occurs in flagellates like Euglena.
• Transverse binary fission: The cell division takes through the transverse plane. Prominent examples of this binary fission include Paramecium, Planaria, Diatoms, and bacteria.

• Oblique binary fission: In this process, the cytoplasm divides obliquely. Oblique binary fission takes place with cerium.

2. What does Hermaphrodite mean?
Ans: Hermaphrodite or bisexual animals are those that have both male and female reproductive systems. Earthworms and snails are a couple of examples.

3. What is strobilation?
Ans: Strobilation is the practice of repeatedly forming similar segments through the budding process. A strobila (also known as a scyphistoma) larva is a segmented portion of the body, while an ephyra larva is a segmented larva (a coelenterate).

Introduction

Transport is a crucial component of plant physiology and involves moving organic nutrients and water throughout the plant body. Food is produced by photosynthesis in the leaves which is transported to other parts of the plant and water is absorbed from the soil through the roots and then to various aerial regions of the plant. In higher plants, the transport of food and water takes place through specialized structures known as the xylem and phloem. An elaborate root system helps these plants to absorb water from the soil.  However, primitive plants perform the function of absorption of water through simple structures such as pores, or the external body surface.

For more help, you can Refer to our video in Class 7 Science in Lesson no 11. Check out the video Lesson for a better understanding.

Transportation in plants-

The main 3 means of transport in plants are via diffusion, Facilitated diffusion, and Active transport. Vascular bundles assist in the movement of water and carbohydrates throughout the entire plant body.

Simple Diffusion- Diffusion is the process of movement of a molecule from a location of higher concentration to a lower concentration i.e. along the concentration gradient. It is a spontaneous process and doesn’t require any energy. Here no special membrane proteins are required and this method only allows the transportation of hydrophobic molecules as the cell membrane is made up of a lipid bilayer.

• Facilitated diffusion- Facilitated diffusion is a type of diffusion facilitated by some proteins which assist in the movement of various metabolites through the cell membranes. These are majorly used for the transportation of water, ions, and other hydrophilic molecules which cannot pass through the lipid bilayer. The channel proteins and the carrier proteins are the two different types of membrane transport proteins.
• Channel proteins- Pores in the plasma membrane are created by channel proteins. These proteins are highly selective and hence allow the transportation of specific molecules only. Eg-Aquaporins only permit water movement and Aquaglyceroporins facilitate only the movement of glycerol and water.
•  
• Carrier proteins- These are special types of proteins that undergo conformational changes after binding to a particular solute. Carrier proteins help in the transportation of ions eg- chloride-bicarbonate exchanger, also known as the anion exchange protein, which facilitates the simultaneous transit of HCO3- and Cl–. It also helps in the transport of glucose via the glucose transporter(GLUT).
• Active transport- Active transport facilitates uphill solute movement throughout the cell by functioning against a concentration gradient. Here the molecules move from an area of lower concentration to a higher concentration. Hence, some kind of energy is required. There are two ways to supply energy:

• The energy produced by ATP hydrolysis is known as primary or direct active transport. For instance, the energy is given through the Na+-K+ ATPase (electrogenic pumps). 

• The energy supplied through the electrochemical gradient is enabled by the Symport pumps (such as the Na+-Glucose symporter, lactose permeases, etc.) and Antiport pumps (such as the Na+-Ca2+ antiporter) These are often referred to as secondary or indirect active transport.

Transport of water from roots

Long-distance transportation of water and nutrients in plants takes place through the xylem and phloem. The soil-plant-atmosphere continuum (SPAC) is a pathway that discusses the movement of water from the soil, its transportation to plant parts, and 

the expulsion of water from the plant. Absorption of water in plants occurs through-Passive absorption- when water is absorbed from a higher water potential (in soil) to a lower water potential (in root cells). Active absorption-which occurs due to transpiration.

Ascent of sap

The term “ascent of sap” refers to the movement of water and minerals from the soil to aerial portions like leaves and stems. The cohesion-tension theory, also known as transpirational pull, explains this (Dixon and Jolly, 1894). According to this idea, water from locations with higher water potential (such as the roots) is drawn up, to areas with lower water potential (the leaves)  due to the tension (negative hydrostatic pressure) which is generated by the leaves. There is low water potential in the leaves because they lose water due to the process of transpiration. The water column is kept from collapsing by the cohesive forces of attraction between the water molecules. As a result, water absorption happens to make up for the transpirational loss.

Summary

Intricate transportation networks are needed by plants to enable the interchange of materials and nutrients. The passive process of moving molecules from higher to lower concentrations is known as diffusion. It could be simple (independent) or facilitated transport. Energy is spent during active transport, which is carried out by membrane proteins called transporters and channel proteins. The transpirational pull/cohesion-adhesion principle is used by the roots to absorb water. 

Frequently Asked Questions

1. What do you understand about water potential?
Ans: The potential energy of water per unit volume is referred to as water potential. It describes the amount of water in the atmosphere, plants, and soil.

It is shown as the sum of Osmotic potential, matrix potential, hydrostatic potential, and gravitational potential. 𝜳w = 𝜳𝛑 (osmotic potential)   + 𝜳m (matrix potential)  +𝜳p (hydrostatic potential)  +  𝜳g (gravitational potential).

2. What is the symplastic pathway of water absorption?
Ans: The continuous network of cell cytoplasms is known as the symplastic route.

Through the plasmodesmata connections present between two cells, this pathway allows absorbed water to flow from cell to cell.

3. Which method of water absorption is quick?
Ans: The apoplastic pathway will move more quickly since there won’t be as many obstacles in its path as there are in the symplastic pathway, which is obstructed by Casparian strips and must travel through the protoplasm, which slows down movement.

Introduction

Evolution is an intricate and slow process. Various organisms constantly adapt by changing their morphological and anatomical characteristics in response to the change in the environmental conditions of their habitat. They make minor changes in their genetic composition to adapt to their surroundings and thrive in their niche. These, minor alterations in their genes are responsible for the formation of new species. Adaptive radiation is one such process by which organisms of a single species rapidly transform into distinct forms to propagate successfully and thrive in their niche.

Factors causing adaptive radiation

Various factors are causing adaptive radiation some of them are-

• Geographical isolation– Geographic isolation of organisms from the mainland due to the formation of valleys, mountains, earthquakes, etc. becomes one of the main reasons for adaptive radiation to take place. This sudden separation causes organisms to rapidly adapt to new changes and hence evolve.
• Exposure to new habitat– When organisms are exposed to new habitats, they are exposed to lots of new resources which are available abundantly. This abundance of resources forces them to diversify and adapt in a way that they can exploit those resources to the maximum and thus cause the evolution of new features.
• Changes in environmental conditions- Change in environmental conditions can occur due to floods, volcanic eruptions, deforestation, weather changes, etc. These changes are sudden and hence force the organisms living in particular habitats to change rapidly and hence lead to adaptive radiations.

All of the above factors cause a change in the genetic composition of the organisms and hence lead to the formation of new and permanent changes in their genotype which then in turn leads to the formation of newer species.

Distinctive features of Adaptive radiation

Distinctive features of adaptive radiation which separate it from other evolutionary changes are as follows-

• Common ancestry- Organisms that undergo adaptive radiation belong to the same ancestor. 
• Phenotype-environment correlation- The changes in the phenotype of the species are with the change in the environmental conditions. 
• Trait utility-The new trait thus formed due to adaptive radiation helps the organisms to survive in the new environment. For eg-Darwin’s finches.
• Rapid speciation-This adaptation is a very rapid process as the organisms need to quickly adapt to the changing environment for their survival.

Adaptive radiation in mammals

Adaptive radiation can be studied by various examples once such as limb structure in mammals which is used for locomotion.

• Modern placental mammals are incredibly diverse in terms of size, behavior, and many other features. They may be found practically anywhere in the world.
• These mammals are descended from a little, short-legged, terrestrial predecessor that consumed insects.
• The pentadactyl (five-fingered) small legs belonged to the insectivorous ancestor. Despite being terrestrial, the appendages cannot move the creature.
• The extinction of dinosaurs suddenly caused the remaining mammals to undergo fast diversification. This gave rise to a variety of modern mammals through the process of adaptive radiation.

Mammals followed five separate evolutionary lines and evolved features to fit their respective surroundings, these adaptations are-

• Arboreal placental animals- These are climbers and are generated by growing appendages with grabbing capabilities. Example: Monkeys and tree-dwelling squirrels.
• Aerial placental mammals- These mammals can fly. They evolved limbs into flying wings. Examples- are gliding squirrels and bats.
• Aquatic placental mammals- These can swim in the water. They have appendages that are designed specifically for swimming and surviving in water. Examples- Whales, dolphins, seals, polar bears, sea lions, and walruses.
• Fussorial placental mammals- These are burrowing mammals and bear strong pentadactyl limbs allowing them to dig down far into the ground. Example- moles and badgers.

Cursorial placental mammals- These mammals evolved limbs to allow for swift ground movements such as running, climbing, walking, etc. Examples-wolves, are horses, pigs, antelopes, and lions.

Even though each of the aforementioned groups of placental animals has limbs that are specific for particular habitat, they all shared a common ancestor that had pentadactyl limbs. These evolutionary lines that radiated out in different directions served the purpose of locomotion in their respective habitat.

Summary

Understanding adaptive radiation aids in the comprehension of how organisms interact within a given habitat. Although the food web provides clear knowledge of species interactions, examining adaptive radiation evolution might help us understand how species are dependent on one another. Adaptive radiation enables us to gain new insights into the environmental changes which influence evolution.

Frequently Asked Questions

1. Does adaptive radiation favor biodiversity?
Ans: When a common ancestor diversifies into various forms to fit into the new environment it is known as adaptive radiation. The newly developed adaptive species then gradually diverge from their ancestor until they no longer resemble them. Since adaptive radiation occurs quickly and in multiple directions at once, it leads to biodiversity.

2. How does adaptive radiation operate?
Ans: As a result of being exposed to new ecological conditions, organisms constantly diversify. They do this to take full advantage of the environmental conditions. Therefore, the process of adaptive radiation has been continuously driven by the formation of new ecological niches which increase the availability of newer resources for survival.

3. Is it accurate to say that only species with the ability to move can benefit from adaptive radiation?
Ans: Moving to a new environment is not the only way for an organism to adapt or experience a different environment. Adaptive radiation can also affect sessile plants. For instance, a single common ancestor gave rise to 28 species of Hawaiin silverswords. They belong to three distinct genera and fill various niches.

Introduction

Environmental changes are natural and will continue to occur from time to time. Change can be abrupt or gradual, like climate change and global warming. Because of the changing environment, some creatures become extinct while certain species can thrive with very minor alterations. These modifications are passed down across generations, enabling the species to adapt to its environment and increase in population. These modifications are known as adaptations. A natural environment where a species grows and reproduces is known as a habitat.

Depending upon various habitats there are the following adaptations–

For more help, you can Refer to Lesson 9 – Living things and habitat in Science Class 6. Check out the video Lesson for a better understanding.

Adaptations in aquatic habitats

Numerous elements, such as light penetration, water composition (nutrient and salt content), oxygen availability, pressure, etc, are various factors that affect life in the aquatic environment. For these purposes, plants and animals are adapted in the following ways-

Plant adaptations-

• Aquatic plants have tissues called aerenchyma to move oxygen from exposed surfaces to low-oxygen submerged sections. 
• Aerenchyma also provides buoyancy to the plant and helps it float and helps to absorb natural light and oxygen.
• The root system is essentially nonexistent because water is all around them. If existent, it is rather small and mostly used for anchorage.
• To endure water currents leaves on submerged plants are typically tiny or ribbon-shaped.
• The stems are tall, hollow, light, and slender.
• Examples include water lilies, sea grass, and lotus.

Animal adaptations-

• Aquatic animals use their gills to breathe.
• Syphons are breathing tubes used by aquatic insects to draw oxygen from the air when submerged in the water. While some creatures, including salamanders, breathe through the skin.
• The blow holes on larger animals like whales and dolphins allow them to take in oxygen as they ascend to the surface and expel carbon dioxide.
• Fish have streamlined bodies to lessen swimming-related water resistance.
• Fins aid in swimming and tails act like rudders to maintain direction.
• Dolphins, whales, fish, etc. are a few examples.

Adaptations in desert habitat

Deserts are dry areas that only get a little rain occasionally throughout the year. It has an arid climate and rocky, sandy soils. Deserts face high temperatures and intense sunlight. For these purposes, plants and animals are adapted in the following ways-

Plant adaptations-

• A common desert adaptation is to conserve body fluids and prevent water loss through transpiration. To stop water loss through transpiration, desert plants’ leaves have thick, waxy cuticles.
• Due to the poor external availability, the stems are fleshy and store a lot of water.
• Desert plants have spines as a kind of defense against herbivores.
• To access deep subterranean water resources, plants have long, deep roots.
• Cacti, and agave, are some examples of desert plants.

Animal adaptations-

• The temperature in the desert is usually very high, hence small organisms have evolved nocturnal behaviors to ensure their survival. At night, when temperatures are generally low, they hunt for prey.
• Many desert animals have skin that is made to keep water from evaporating, and their bodies store lipids which can help them endure prolonged hunger periods.
• High-speed winds frequently carry small sand particles; these animals have large eyelashes, hairy ears, and tight nostrils which prevent sand from getting into their delicate bodily parts.
• Desert animals include kangaroo rats, camels, and desert cats.

Summary

Every living thing is constantly interacting with its environment. The percentage of survivors they have will determine how long the species will exist. Changes in the environment might be gradual or abrupt. However, organisms—whether they be plants or animals—develop specific inherited traits that enable them to adapt to environmental changes. We refer to them as adaptations. Desert-dwelling organisms have developed adaptations that reduce body water loss. Water-dwelling organisms have developed adaptations that help them breathe and adjust to the water pressure. Adaptations help organisms function better and are essential for survival.

Frequently Asked Questions

1. Give some common examples of adaptations.
Ans: Some examples of adaptations are- 

• Pointed teeth and claws of carnivores.
• Varied beak shapes to obtain food.
• Webbed feet of ducks.
• Leaves thick cuticles in xerophytic plants.
• White color fur in arctic animals prevents predation.
• Uricotelism in xerophytic animals.

2. What are Physical, physiological, and Behavioural adaptations?
Ans: Physical adaptations are characteristics that organisms have acquired as a result of their environment. To live in their ecological niche, organisms engage in internal functional mechanisms known as physiological adaptations. Behavioral adaptations are the behaviors or reactions the organism does in response to its surroundings.

3. Describe camouflage.
Ans: The physical adaptation of creatures to resemble or blend into their surroundings to survive attacks from predators is called camouflage.

Introduction

Mammals, fish, amphibians, birds, and reptiles are among the five classes into which animals are divided. Each one of them needs the environment to survive, including air, food, water, and shelter. The only vertebrates that live part of their lives in water and part on land are amphibians. As a result, they differ from other animal species. An amphibian is a tiny vertebrate organism that requires water or a moist environment to exist. As amphibian’s body temperatures are influenced by their surroundings and they can thrive in both terrestrial and aquatic habitats, they are also referred to as cold-blooded vertebrates. Frogs, toads, newts, caecilians, and salamanders are amphibians.

Characteristics of Class Amphibia

Body 

• Amphibian bodies are separated into the head, trunk, and tail. Few amphibians just have a head and a tail (frogs). The neck can be absent or present.
• Some amphibians are limbless, while others have two sets of pentadactyl limbs.
• The skin is smooth, moist, scale-free, and abundant with mucous glands.

Sense organs

• Amphibians have two olfactory lobes that are responsible for their ability to smell.
• Eyes are well developed.
• Although they lack an external ear, the tympanum shields their middle ear.

Digestive system

• Amphibians have digestive systems that include the mouth, oesophagus, stomach, and intestine closing in a division called the cloaca.
• Cloaca participates in the digestive, excretory, and reproductive systems.

Circulatory system

• Amphibians have a closed circulatory system.
• They have three-chambered hearts, that are made up of two auricles and one ventricle.
• There are two circulatory paths; one is for the oxygenation of the blood through the lungs and skin and another route is to carry oxygen to the remaining parts of the body.
• However, there is incomplete double circulation because the oxygenated blood obtained in the left atrium and the deoxygenated blood received in the right atrium mix very slightly.

Diet

• Invertebrates like bloodworms, mealworms, earthworms, snails, slugs, locusts, and other creatures are eaten by amphibians. Larger amphibians can also consume small mammals.
• Young frogs require food most days of the week, whereas adult frogs only require it every two to three days.

Excretory system

• Amphibians have mesonephric kidneys during the adult stage and have pronephric kidneys at the larval stage.
• When on land, they expel the majority of their metabolic waste as ammonia (in tail form) and urea (in tailless forms).
• Kidneys are the primary excretory organ of amphibians.

Reproduction

• Amphibians can be fertilized internally (by a salamander) or externally (by most amphibians).
• They attract their mates by making various sounds; for instance, the loud croaking of frogs may be a signal for mates.
• Since the eggs don’t have shells and get dry when kept on land, the eggs must be laid in freshwater.

Classification of Amphibia

Based on their order, amphibians can be divided into three groups they are-

Apoda (Gymnophiona or Caecilia)

• The body is elongated and can be differentiated into the head and trunk. 
• They do not have limbs and hence resemble earthworms.
• They have small dermal scales
• As their eyes are covered by bone or skin, they are known as blind worms.
• They lack tails or may have short tails.
• Internal fertilization takes place.
• Eg-Caecilians

Urodela (Caudata)

• The body is long and differentiated into a head, neck, tail, and four limbs which are of similar length.
• Their skin is smooth and moist.
• Through their skin, they breathe.
• At both the larval and adult stages, they have teeth in their jaws.
• They are incapable of making sounds.
• They undergo fertilization either internally or externally.
• Examples-Newts and Salamanders

Anura (Salientia)

• The body is differentiated into the head and trunk. But both of them are fused.
• They have four limbs that are designed specifically for jumping.
• Their mouth is large.
• At the larval stage, the tail is present and the adult tail is absent.
• Due to the presence of a chemical called magainin, the skin secretions of anurans have a naturally occurring antibiotic effect.
• In anurans, external fertilization takes place.
• Examples: Toads and frogs

Scientific Classification of Amphibia

The scientific classification of amphibians is as follows-

Domain	Eukaryote
Kingdom	Animalia
Phylum	Chordata
Subphylum	Vertebrata
Class	Amphibia
Order	Urodela  Apoda Anura

Summary 

Cold-blooded creatures called amphibians descended from lobe-finned fish. When they are larvae, they can survive in water, but as adults, they must live on land. Frogs, toads, salamanders, newts, and caecilians are some examples of amphibians that are grouped into orders such as  Apoda, Urodela, and Anura. They have different body types. During the younger stage they breathe through the skin(gills) and as they reach adulthood, their lungs develop and they now breathe through both skin and lungs.

Frequently Asked Questions

1. Explain metamorphosis.
Ans: Metamorphosis is the term used to describe the changes an animal undergoes during its life cycle. When a frog egg hatches, a tadpole is released, which first grows rear legs then develops the front legs, and then finally becomes an adult frog.

2. Give the 5 kingdom classification with examples.
Ans: The 5 kingdom of classification was proposed by RH Whittaker in 1969. 

The 5 kingdom classification is-

• Kingdom Monera- it includes the prokaryotes.
• Kingdom Protista- it includes single-celled eukaryotes.
• Kingdom Fungi- it includes various fungi.
• Kingdom Plantae- it includes all types of plants
• Kingdom Animalia- it includes all types of animals.

3. How do amphibians breathe?
Ans: The majority of amphibians can breathe through their skin, which is a thin, permeable organ that is dense with blood vessels. In their larval stage, some aquatic animals, like frogs, have gills that absorb oxygen from the water and expel carbon dioxide as waste.

Introduction

Apiculture is the practice of culturing honey bees on a bigger scale to yield beeswax and honey. It is a scientific approach to rear the bees in man-made hives, raising their numbers and caring for them. Beekeepers or apiarists are those who practice apiculture. Man-made beehives are artificial bee hives. These are made of wooden boxes and contain rows. Bees stay in these hives and fill the rows with wax, honey, etc. The designs of these hives should be such that they will facilitate the healthy growth of bees and honey harvesting.

How honey is collected by honey bees?

Long distances are covered by worker bees as they search for food. Their honey stomachs serve as temporary storage for the nectar they obtain from flowers. When they get to the hive, they regurgitate this nectar and deposit it in honeycombs. The regurgitation is a viscous liquid called honey that has undergone dehydration.

The life cycle of the Honey bee

Honey bees go through four developmental stages. They begin as eggs, grow into larvae, then transition into the pupa stage before reaching adulthood.

• Egg stage- After a drone successfully fertilizes a queen bee,  she lays both fertilized and unfertilized eggs. A queen bee may produce between 2000 and 3000 eggs every day, each of which is contained in a cell. Unfertilized eggs grow into male drones, whereas fertilized eggs become worker bees.
• Larval stage-After three days the eggs hatch into worm-like larvae.  Larvae are without legs, wings, or other appendages. Royal jelly is provided to larvae during the first two to three days, followed by pollen and honey. Only royal jelly is used to feed the queen larva.
• Pupal stage-In this stage the larvae wrap themselves up in a cocoon and enclose themselves in their cells. During the pupal stage, all organs such as the abdomen, head, eyes, thorax, and appendages including wings, legs, and antennae are developed completely.
• Adult stage- Once the larvae develop, they appear like adult bees after they hatch out from the capped cell.

Common varieties of bees

Common honey bee species include-

• Apis dorsata.– As well known as rock bees they are enormous, vicious bees. The raising of rock bees is challenging.
• Apis Florea– Referred to as “little bees” because of their tiny size. They rarely sting, but because they move around a lot, domestication is fairly challenging.
• Apis mellifera– Also known as the western bee or European bee. It is the most domesticated species in the world and stings less frequently.
• Apis indica– Frequently called Asian bees or Indian bees. They originated in Asia and are simple to domesticate to make honey.

Importance of Beekeeping

• The purpose of apiculture is to produce bee products that have a marketable value.
• Honey is the main apicultural product that is obtained. Because of its distinct sweetness, honey is employed extensively in the food sector.
• Additionally, several therapeutic herbs and honey are combined in some traditional medicines.
• The glandular fluid made by honey bees for the construction of the honeycombs in which they store their honey is known as beeswax.
• In the production of soaps, candles, and cosmetics, beeswax is commonly used.
• Another type of glandular fluid produced by worker honey bees, which is used for feeding queen bee larvae is the royal jelly.
• This royal jelly improves collagen synthesis and helps women who are experiencing menopause-related issues.
• Propolis, a resin-like substance made by honey bees, has antiviral and antibacterial properties.
• Bee venom has been shown in several trials to be effective in combating the Human Immunodeficiency Virus (HIV).
• Beekeeping also has environmental benefits as bees are great pollinators and help in fruit formation.

Summary

Apiculture is the scientific process of rearing honey bees in artificial hives to produce bee products such as honey, wax, royal jelly, and propolis for the market. An apiculturist is a person who does apiculture. In addition to providing advantages to business and industry, apiculture supports numerous plant species through pollination.

• The species of bee most frequently raised for the production of honey is Apis mellifera.
• Apiculturists take care of wooden-framed hives where honey bees can breed and grow.

Most apiaries are designed around bee pastures because they make excellent locations for bee foraging. Queen bee, worker bees, and drones are present in every bee colony. Within their colony, they are assigned specific duties. The life cycle of honey bees has four stages. Queen bee lays eggs that completely metamorphose into adult bees. 

Frequently Asked Questions

1. How do bees act as pollinators?
The pollen grains from stamens land on the hairy region of the hind legs of the bees while they are collecting nectar. When the honey bees visit another flower they deposit pollen grains there and hence aid in cross-pollination. Honey bees are therefore referred to be pollinators because of this.

2. What are the various types of bees found in a bee hive?
Ans: There are a lot of bees within the bee hive. They can be divided into three primary groups.

• Queen Bee- The only female in the bee hive with the ability to lay eggs is the queen bee. The queen uses pheromone emissions to regulate the entire hive population.
• Drones or male bees- They are the male population of the hive that fights it to mate with the queen bee. After mating, the drone bee dies.
• Worker bees- These bees are female and unable to lay eggs. They are the bee hive’s active population. Worker bees perform a variety of tasks, such as maintaining and cleaning the hive, and feeding larvae and queen bees. They produce honey and gather the nutrients required for the hive population.

3. Who is known as the father of apiculture?
Ans: The father of modern apiology and apiculture is Johann Dzierzon. Most modern beehives derive from his design.

Introduction

The word ‘amnio’ (Greek in origin) means inner membrane around the foetus and ‘centesis’ means to prick i.e. amniocentesis refers to the procedure of obtaining amniotic fluid by making a tiny puncture in the inner membrane surrounding the foetus. It is a prenatal test which is carried out before or during pregnancy. Amniocentesis is a procedure used to detect particular genetic disorders which may be due to some chromosomal abnormalities or aberrations. Genetic disorders such as colour blindness, haemophilia, Turner’s syndrome, Down syndrome, etc can be detected through this process. It is often carried out after 15 weeks of pregnancy, or after the first trimester (3 months). If an abnormality is found during this process, then depending upon the health of the baby the decision will be taken whether to continue the pregnancy or not.

Procedure of Amniocentesis 

Amniocentesis is performed by a team of professionals. A small amount of amniotic fluid is removed from the abdomen using a needle and is submitted to a lab for analysis. Amniocentesis is an intrusive process that involves inserting a needle into the uterus.

The procedure of amniocentesis is as follows-

• Ultrasound-To determines the position of the placenta, the foetus’ movements, and the features of the amniotic fluid an Ultrasound is conducted. An ultrasound helps to decide which needle to use, the area where the needle will be inserted and the angle at which the needle can be administered.
• Sterilisation-To reduce the danger of infection, the abdomen is first sterilised with an antiseptic, and tools with heparin coatings are used to prevent blood clotting.
• Needle insertion-Depending on the doctor’s preference, either a single-needle or two-needle approach is employed for the needle insertion. To ensure that a good quality sample is extracted the needle is injected in a specific location, and 20 ml of amniotic fluid is extracted.
• This fluid collected is sent to the laboratory for analysis of any genetic disorders.

Reasons  for performing  Amniocentesis 

Some of the common reasons to perform amniocentesis are as follows-

• The main purpose of amniocentesis is to find genetic disorders such as Down syndrome, Turner’s syndrome etc.
• Additionally, neural tube abnormalities, in which the brain and spinal cord are still immature, can also be found through this process.
• It is used to determine whether the lungs of the developing foetus are mature enough for the foetus to take birth.
• When a mother’s blood has an Rh infection i.e. the mother’s blood produces antibodies against foetal blood the baby may develop anaemia. This can be detected by amniocentesis and can be cured.
• Sometimes excessive amniotic fluid gets accumulated in the body, then this process can detect it and excessive amniotic fluid can be removed.
• DNA from the collected amniotic fluid is used in paternity tests to determine blood relations.

Summary

Genetic disorders in the growing foetus are identified using a procedure called amniocentesis. The defects in chromosomes created during cell division are the root cause of genetic diseases. Amniotic fluid, which contains foetal cells, surrounds the foetus. This fluid is sampled in small amounts to perform the examination and look for any abnormalities in the foetus. If there are any abnormalities then depending on the condition of the baby and its health the decision of aborting the child or keeping the child is taken.

Frequently Asked Questions

1. What are the various risks involved in the process of amniocentesis
Ans: There are various risks associated with the process of amniocentesis such as-

• Amniocentesis can cause miscarriages as a small cut is made to extract the amniotic fluid.
• This procedure can cause cramping in the mother as she has to stay still during the entire process.
• There is a high chance that this process can cause injuries to the foetus.
• If the process is not done correctly then it might cause leaking of the amniotic fluid through the point of puncture.
• If by chance this process is done in the second trimester of the pregnancy then there are chances of preterm labour.

2. What precautions should be taken post performing amniocentesis
Ans: Following precautions should be taken post-amniocentesis-

• Normal activities can be resumed after the amniocentesis operation, however rigorous activities should be avoided for up to 24 hours.
• If post operation she suffers vaginal bleeding or a significant loss of amniotic fluid, she must immediately see a doctor.
• If the mother has a fever, severe uterine cramps for more than a few hours, and no abnormal foetal activity and redness or inflammation where the injection was made, then she should immediately see the doctor.

3. What happens if a test for Down syndrome is positive?
Ans:  If the test results are positive you will be offered a diagnostic test, typically a chorionic villus sample (CVS) or maybe an amniocentesis, Whether or not the pregnancy is truly impacted will be depended on the test that is performed. CVS is usually done between 10 and 13 weeks of pregnancy.

Introduction 

Human Anatomy is the discipline of science that focuses on the structural composition of humans. It is a Greek word wherein “ana” is (up) and “tome” is (cutting). Anatomy is the study of how the human body is arranged and made up of cells, tissues, organs, and organ systems. Human physiology is a branch of science that deals with the activities and functions of the vital life processes within the human body. There are various types of physiology such as Cell physiology, Special physiology, Systemic physiology, and Pathophysiology. The human body is comprised of multiple organ systems such as the respiratory system, digestive system, nervous system, cardiovascular system, urinary system, and reproductive system.

Learn More about Anatomy and Physiology of Human Body. Check out more videos in Science Class 6 Lesson no 08.

Circulatory system

The human circulatory system is made up of the heart, arteries, veins, and capillaries. This system is used to transport blood and lymph throughout the body. It also provides nutrition and removes nitrogenous waste from the body. It is also called the cardiovascular system. Humans have a closed circulatory system, where blood flows in specific blood vessels. Below given are the components of the circulatory system and their function.

Organ	Structure and Components	Functions
Heart	The human heart contains four chambers: the right and left atrium, and the right and left ventricle. It has specialized cardiac muscle with many valves.	It pumps blood throughout the body.
Arteries(blood vessels)	Thick-walled, valveless.	Transport blood from the heart to other parts of the body (exception- the pulmonary artery).
Veins   (blood vessels)	Thin-walled and have valves.	Transport blood from the other parts of the body to the heart (Exception- for the pulmonary vein).
Capillaries	Thinnest blood vessels.	Connects arteries and veins.
Blood	50–55 % of blood is made up of plasma and 45-50% is made of blood cells like RBC, WBC, and platelets.	Act as the medium of transport of nutrients, gases, and nitrogenous wastes.

Respiratory System

• Respiration is the process of oxidation of food materials to liberate energy. 
• There are two types of respiration internal and external respiration. The inhalation and exhalation of air with the help of the lungs are known as external respiration. Here carbon dioxide is exhaled and oxygen is inhaled.
• Internal respiration is also known as cellular respiration which occurs in the mitochondria and produces energy in the form of ATP. 
• The human respiratory system is made up of the Nostrils, pharynx, Larynx, a pair of lungs, and Diaphragm. 
• The lungs are made up of Trachea, Bronchi, Bronchioles, and Alveoli.

Digestive system

• Digestion is the breakdown of complex food substances into simpler nutrients such as carbohydrates, proteins, etc. which are easily absorbed by the body. 
• The digestive system secretes various enzymes which assist in the digestion of food material. Digestion occurs in 5 steps given as follows-

Steps	Involved organs	Function
Ingestion	teeth, tongue, and palate.	Intake of food materials such asrice, fruits, vegetables, etc.
Digestion	Mouth, salivary glands, liver, stomach, pancreas, small intestine.	Food is digested and broken down into simpler soluble and absorbable forms such as sugars, amino acids, fatty acids, etc.
Absorption	Villi of the small intestine.	The food thus broken into simpler substances is absorbed in the blood and transported to various organs of the body.
Assimilation	Cells, tissues	Absorbed food is utilized by cells and tissues for their cellular activities.
Egestion	Large intestine and anus.	Excretion of unusable or undigested material from a cell.

Reproductive System

• Humans are sexually dimorphic. They perform sexual reproduction and give rise to the next generation. 
• The human reproductive system is different for males and females. 

Female reproductive system–

• The female reproductive system is situated in the pelvic girdle.
• It produces eggs that are haploid and fuse with the sperm to form the zygote and then the fetus.

The female reproductive system is made up of the following-

Sex organs	Functions
Pair of Ovaries	That Contain eggs and perform Oogenesis and ovulation.
Genital Tract (Fallopian Tubes, Uterus, Vagina)	Fertilisation, ovulation, carrying a baby, and giving birth.
External Genitalia	Respond to sexual stimulation.
Mammary Gland	Produces milk for the newborn child.

Male reproductive system –

• The male reproductive system is situated in the pelvic girdle and produces sperm.
• They contain the penis which is an ejaculatory organ that transfers sperm in the female body.

The male reproductive system is made up of the following organs

Sex organs	Functions
Pair of Testis	Secreting testosterone and producing sperm.
Epididymis	Develop the sperm.
Ejaculatory ducts	Transport mature sperm to the urethra.
Urethra	Ejaculating semen.

Nervous system

• The body’s primary controlling, regulating, and communication system is the nervous system.
• The ability to move, breathe, see, think, learn, remember, and more is controlled by this system,
• The nervous system is made up of neurons, nerves, and ganglia which carry messages to the brain and the entire body.
• Neurons are made up of axons, dendrons, and a  cell body.
• The brain and spinal cord make up the central nervous system.
• The Somatic Nervous System and the Autonomic Nervous System make up the Peripheral Nervous System.

Urinary system

• The urinary system of the body is used for expelling waste products from the body. The waste products are in the form of urine. 
• A pair of kidneys perform the function of excretion. Its structural and functional unit is a nephron. 

Following are the parts of the urinary system.

Organ	Function
A pair of Kidney	Performs ultrafiltration of the blood and removes waste products from the body in the form of urine. It also performs the function of osmoregulation.
A pair of Ureter	Carries the urine downward.
Urinary Bladder	Storage organ which stores urine temporarily.
The urethra	Passes the urine outside the body.

Immune system

• The immune system of an organism protects the body from infection.
• The immune system fights the antigen (pathogen) by forming antibodies. These antibodies kill the pathogen and thus the steady state of the body is maintained.
• The organs of the immune system are-spleen, thymus, lymph nodes, blood, etc.
• The cells of the immune system include-Stem cells, T-lymphocytes, B-lymphocytes, Monocytes, Cytotoxic and Helper cells, Neutrophils, etc.

Summary

Anatomy of the human body is the study of the structure and relationship between all organs of the body. However, the physiology of the human body explains how each organ performs. The body’s organ systems collaborate to carry out a certain activity or set of duties. The respiratory system, digestive system, nervous system, cardiovascular system, urinary system, and reproductive system are various organ systems in the body that operate together and support healthy body development, growth and reproduction.

Frequently Asked Questions

1.State the types of anatomy.
Ans: The different types of anatomy are-

• Gross anatomy- Gross anatomy entails the dissection of organs on a larger scale for examination.
• Cellular anatomy- Investigating cells and cellular components under a microscope are called “cellular anatomy.”
• Molecular anatomy- DNA, RNA, proteins, and other biochemical components are studied in molecular anatomy.

2. How is the human body organized?
Ans: Cells are the structural and functional unit of life. The human body is made of cells. These cells combine and form tissues, tissues form organs, organs form organ system and all these systems together build the human body.

3. What are primary and secondary sex organs in humans?
Ans. The primary sex organs are those organs that produce gametes. In females, the primary sex organ is the ovaries which produce egg cells. In males, the primary sex organ is the testes which produce sperm.

Secondary sex organs are those that transport and store the gametes and nourish the growing baby. Male secondary sex organs are Epididymis, vasa deferentia, penis, etc. Female secondary sex organs are- the fallopian tube, vagina, uterus, etc.

Introduction

Animals come in a variety of shapes and sizes. Members of this kingdom are Multicellular, eukaryotic animals that have a heterotrophic mode of nutrition and their cells are devoid of cell walls. They are typically motile that move from one place to another. Animals come in a variety of shapes and sizes. 

Classification of Animal kingdoms based on their characteristics

Animal classification is based on various characteristics such as

• Arrangement of cells
• Symmetry
• Coelom or body cavity

Arrangement of cells

All animals are multicellular but the arrangement of cells within them is different. This arrangement of cells is known as the levels of the organization. Based on this animals are classified under

• The cellular level of organization- Animals at this level of organization generate loose clusters of cells. Eg. Sponges.
• Tissue level of organization-Animals under this level has cells that combine to form tissues and all tissues perform various bodily activities.
• Organ level of organization-  Animals with an organ-level organization are those in which tissues with the same functions group together to form an organ.
• Organ system level of organization-Organ system degree of organization is displayed when organs work together to produce an organ system that performs many physiological functions.

Symmetry

• The symmetry of an animal’s body can be used to classify it.
• The body exhibits three different types of symmetry.
• Asymmetry is symmetry where the plane is not divided into two equal halves. It was observed in the phylum Porifera (sponges).
• Radial symmetry is a symmetry that divides a plane passing through the central axis into two halves. This is seen in phylum Coelenterates, Ctenophores, and Echinoderms.
• When a  plane separates the body into two identical left and right halves then such symmetry is known as bilateral symmetry.
• Arthropods and annelids are two examples of animals with bilateral symmetry.

Coelom or body cavity

• The coelom is the space that is found between the body wall and the alimentary canal. Based on body activity organisms are classified as-
• Acoelomates- They do not have a body cavity. Eg- members of Phylum Platyhelminthes.
• Pseudocoelomates–They have a false body cavity. Eg. members of Phylum Aschelminthes.
• Coelomate- They have a true body cavity that is filled with coelomic fluid. This is seen in members from Phylum Annelida to Phylum Chordata.

Phylum belonging to Kingdom Animalia

Phylum Porifera

• They are also known as sponges.
• They are multicellular organisms that are organized at the cellular level.
• They have asymmetrical body shapes and are typically found in marine environments.
• They have a water canal system. Water enters the body through the Ostia (pores) that are lined up on the surface of the body. From here it is conveyed into the spongocoel. Water exists in the body through the osculum.
• The movement of water facilitates gas exchange, food capture, and water excretion.
• Porifera members are Hermaphrodites.
• Common examples are Spongilla and Sycon.

Phylum Cnidaria

• They are aquatic, sessile, free-living, and radially symmetric creatures.
• On their body, tentacles, have stinging capsules called cnidoblast. These cnidoblasts
• are defense mechanisms of the organism and it also helps in anchorage.
• They display tissue-level organization and diploblastic structure.
• They have a single opening mouth on the hypostome and both internal and external digesting systems.
• The basic body forms that Cnidarians displays are the polyp and the Medusa.
• Physalia and Adamsia are two examples.

Phylum Platyhelminthes

• They are called flatworms because of their dorsally flattened bodies.
• They live inside animals, including humans, and are endoparasitic.
• Some of them take nourishment straight from their host.
• They are triploblastic, bilaterally symmetric animals that are organized at the organ level.
• They have no true internal body to accommodate well-developed organs for proper functioning. 
• The development happens throughout several larval stages. Fertilization is internal.
• Taenia and Fasciola are two examples.

Phylum Annelida

• They can have a closed circulatory system and can either be terrestrial or aquatic, parasitic or free-living.
• They exhibit bilateral symmetry and organ-level organization.
• Segments and metameres are found on the body surfaces.
• Circular muscles in their bodies aid in mobility.
• The Annelida species perform sexual reproduction.
• Examples-Nereis and Hirudinaria.

Phylum Arthropoda

• In the Kingdom Animalia, it is the largest phylum that includes insects.
• They show bilateral symmetry and organ-level structure.
• They have joint legs and a tough exoskeleton
• Arthropods have a chitinous layer covering their belly, thorax, and other body parts.
• Through Malpighian tubules, they excrete.
• The development may be direct or indirect, and fertilization is typically internal.
• Eg- Cockroaches, Flies, Bees, etc.

Phylum Mollusca

• They are the second-largest phylum of the kingdom Animalia.
• They have an organ level of organization and may be terrestrial or aquatic.
• They have true bodies, triploblastic organization, and show bilateral symmetry.
• Most molluscs have calcareous shells covering their bodies.
• The head, visceral hump, and muscular foot make up the body.
• Internal fertilization occurs and they show indirect development.
• Examples include Pila and Chaetopleura.

Phylum Echinodermata

• Animals have calcareous skin coverings.
• They exist in aquatic settings that are organized at the organ level.
• While adults have radial symmetry, larval-stage animals have bilateral symmetry.
• They have a water vascular system that aids in breathing, locomotion, and food collection.
• There is no excretory system in them.
• Echinoderms show external fertilization and reproduce through sexual reproduction.
• Asteria and Echinus are examples.

Phylum Protochordata

• These creatures are triploblastic and bilaterally symmetric.
• They have a true body and, at some point in their life cycle, a notochord is present.
• They typically inhabit marine areas.
• Examples are Herdmania and Amphioxus.

Phylum Chordata

• This phylum includes creatures like birds and humans.
• The presence of a notochord is a trait shared by all species in this phylum.
• They have a single, hollow central nervous system that is located dorsally.
• A post-anal tail is present, which aids with movement.
• A pharynx is penetrated by gill slits.
• The phylum is further divided into subphyla Urochordata, Cephalaochordata, and Vertebrata.

Summary 

The largest kingdom that includes all animals is called Kingdom Animalia. Several criteria, including the level of organization, symmetry, coelom, segmentation, and notochords, are used to classify these species. Various phyla such as  Porifera, Cnidaria, Ctenophora, Platyhelminthes, Annelida, Arthropoda, Mollusca, Echinodermata, Protochordata, and Chordata make up this Kingdom.

Frequently asked question

1. Describe protozoans.
Ans: Protozoans are-

• Microscopic, unicellular, free-living protozoa are present in practically all ecosystems.
• They are typically parasitic and mobile. 
• Digestion of food by these organisms takes place through the process of Osmotrophy, which is the engulfment of food through cell membranes.

2. How are animals classified based on the circulatory system?
Ans: A network of arteries, veins, capillaries, and the Heart together is known as the circulatory system. There are two types of circulatory systems: open and closed systems.

• In an open system, the blood is pumped into a chamber outside the heart known as the hemocoel rather than being constrained to the blood vessels.
• In a closed system, the blood circulates in one direction from the heart to the surrounding vessels and then returns to the heart. In this system, the blood is contained within the blood capillaries.

3. What do diploblastic organization and triploblastic organization mean?
Ans:

• Diploblastic organization – It is the arrangement of cells in two layers, i.e outer ectoderm and inner endoderm. It is seen in Coelenterates 
• Triploblastic organization -It is a  three-layered arrangement of cells, i.e ectoderm, mesoderm, and endoderm. Common examples are Platyhelminthes, chordates, etc. 

Introduction

The definition of agriculture is frequently misunderstood to mean just the production of crops for food and fiber. Agriculture, however, extends beyond just growing plants, it includes the breeding of livestock for their beneficial products. Since the beginning of time, humans have been raising animals for their own needs. Since humans first domesticated animals some 13,000 years ago, they have developed innovative techniques to increase both the quality and quantity of the things they can produce from animals. 

Types of Animal Husbandry

Dairy Farming

• The practice of raising dairy animals, such as cows, buffalo, goats, and others, for milk production and its subsequent processing to produce products like butter, ghee, cheese, and cream, among other things, is known as dairy farming.
• Native Indian cow and buffalo breeds including the Gir, Sahiwal, Red Sindhi, Siri, Mahiwal, Surti, and Jaffarabadi, as well as exotic breeds like Jersey, Red Dane, and Holstein Friesian, are frequently bred for their desirable traits.
• When raising cows to extract milk, it is essential to maintain the required standards of health and hygiene.
• Good quality and safe-to-consume products are ensured by the good health and excellent living conditions of the animals.

Learn More about Agriculture. Check out more videos in Science Class 8 Lesson 1. Clear your doubts from the Science experts teacher.

Poultry Farming

• The practice of domesticating and raising birds, such as hens, cocks, ducks, geese, and turkeys, for their meat, eggs, and other products is known as poultry farming.
• Different techniques are used by poultry farmers to raise chickens.
• The most popular method is intensive poultry farming, in which hundreds of birds are frequently raised in tier-by-tier battery cages.
• Farmers are becoming more conscious of the drawbacks of intensive farming, which has led to a rise in the popularity of free-range farming.
• In this style of poultry farming, the birds are given free access to a large area during specific hours of the day.
• Better health and disease resistance are encouraged by this practice.
• In poultry farming, hens are raised primarily for two products: eggs or meat.
• It is advised to provide a healthy, disease-free environment, along with decent, nourishing meals and spacious places.

Pisciculture

• Fish rearing for food is often known as pisciculture or fish farming.
• Typically, fish tanks or other enclosures such as ponds are used to raise the fish.
• The fish are fed artificially and later harvested.
• In composite fish culture, both domestic and foreign varieties are raised in the same pond or enclosure.
• The fish that are selected to be raised together must be able to co-exist.
• The most popular fish species raised for food include trout, carp, salmon, tuna, tilapia, etc.

Apiculture

• Apiculture is the practice of raising bees in colonies in places called apiaries to produce honey and other items like royal jelly, beeswax, etc.
• In addition, bees are also utilized for their pollination services.
• For the colonies to expand, beekeepers frequently employ wooden hives.
• Bee farming is a low-cost, low-labor method of farming.
• Bees can be easily grown without the requirement for any fertile ground.
• However, it is important to make sure the bee farm is situated close to a flower garden with enough pollen and nectar.
• In addition, it is necessary to prevent the use of insecticides near the apiaries.

Advantages of Animal Husbandry

Following are the advantages of animal husbandry in agriculture and human welfare.

• The dairy industry in animal husbandry makes a significant contribution to the global food sector by offering a wide range of goods, including milk and its derivatives like butter, various types of cheese, ghee, cream, etc.
• Dairy farming makes a vital contribution to a nation’s economy. With 186 million tonnes of milk consumed yearly. India is one of the world’s largest milk producers.
• In addition to being raised for their milk, dairy farm animals are also used for their flesh.
• Because of its high protein content and flavor meat is a very popular food item.
• Livestock and poultry raised on the grounds, generally graze there, this helps in suppress weed development.
• The items that are obtained from all the reared animals help in increasing the nation’s economy as they are exported to various foreign countries.
• All these animal-rearing activities have generated employment options in rural areas. 
• It has increased food security and provided money to rural impoverished people.
• Utilizing animal waste as manure on farmland is one example of how sustainable practices to aid in the efficient management of waste. It encourages effective nutrient cycling.
• Moreover, manure can be used in fish meals.
• Manure and cow dung are valuable sources of fuel.
• Additionally, animal husbandry is managed to produce fibers that are crucial to the textile industry.

Summary

• The process of raising livestock to exploit their products is known as animal husbandry.
• Dairy farming, poultry farming, fish farming, and bee farming are the four main subfields of animal husbandry.
• Animal husbandry procedures must assure a safe, secure, and healthy environment for the animals’ well-being, which will in turn yield high-quality goods.
• Animal husbandry produces a number of significant goods that are essential to our daily life.
• Additionally, animal husbandry creates job opportunities.

Frequently Asked Questions

1. Differentiate between layers and broiler.
Ans: 

Layers	Broilers
These are chickens that are raised for egg production.	These are chickens that are raised for meat production.
They need protein in less quantity in their  diet.	They require a protein-rich diet.
They need proper spacing and lighting.	They do not need much spacing and lighting.

2. Enlist types of Honey bees used in apiculture.
Ans: Honey bees reared for apiculture are-

• Apis dorsata or The Rock Bee
• Apis cerana indica or The Indian hive Bee
• Apis mellifera or The European Bee
• Apis florea or The Little Bee.

3. Which state of India produces the maximum number of fish under pisciculture?
Ans: Andhra Pradesh is the highest fish-producing state in India. It produces around 34.50 lakh tonnes of fish per year.