Category: Biology

Introduction

Herbs and shrubs are characterized by their growth habit and structure. Herbs are small, non-woody plants that typically have delicate leaves and stems. While Shrubs are larger, woody plants that have persistent stems that provide structure and support. Both herbs and shrubs play important roles in ecosystems and provide benefits to human societies. Understanding the differences between herbs and shrubs can help us appreciate the unique characteristics and uses of each type of plant.

Herbs

Herbs are defined as non-woody plants that are valued for their aromatic or flavorful leaves, stems, flowers, or other parts. They are usually smaller in size compared to shrubs and trees, and can grow either as annuals, perennials, or biennials. Herbs play important roles in various ecosystems, serving as food for pollinators, providing habitat for wildlife, and contributing to soil health. The growth and survival of herbs can be influenced by a variety of factors, including light, temperature, water, and soil nutrients.

In addition to their ecological importance, herbs have also been used by humans for thousands of years for medicinal purposes, as spices and flavorings, and as ornamental plants. Studying the biology of herbs can provide important insights into their uses and benefits to human society.

Examples of Herbs

Here are a few examples of herbs:

1. Basil – a fragrant herb commonly used in Italian cooking
2. Rosemary – an evergreen herb used for cooking and aromatherapy
3. Mint – a refreshing herb used in teas, desserts, and sauces
4. Thyme – a versatile herb used in many savory dishes
5. Sage – and earthy herb used in stuffing, soups, and sauces
6. Lavender – a fragrant herb used in perfumes, soaps, and teas
7. Chives – a mild onion-flavored herb used in salads, soups, and dips
8. Parsley – a bright green herb used as a garnish and in sauces and soups

Shrubs

Shrubs are defined as woody plants that are typically smaller than trees and larger than herbs. They have a persistent woody stem that supports the plant and provides structure. Unlike trees, which have a single main stem (trunk) that supports the entire plant, shrubs have multiple stems that arise from the base of the plant and grow to a more limited height.

Shrubs play important roles in many ecosystems, providing food and habitat for wildlife, stabilizing soil, and helping to maintain biodiversity. They can be found in a variety of habitats, from deserts to wetlands, and can be adapted to different climates and soil types.

Examples of Shrubs

Here are a few examples of shrubs:

1. Blueberry – a fruiting shrub with sweet, juicy berries
2. Rhododendron – an evergreen shrub with showy flowers and glossy leaves
3. Lilac – a deciduous shrub with fragrant flowers
4. Boxwood – an evergreen shrub often used for hedges and topiary
5. Azalea – a deciduous shrub with brightly colored flowers
6. Holly – an evergreen shrub with glossy leaves and red berries
7. Hydrangea – a deciduous shrub with large clusters of flowers
8. Spirea – a deciduous shrub with delicate flowers

Differences between herbs and shrubs

Herbs and shrubs are both types of plants, but they have some key differences:

1. Size: Herbs are typically smaller than shrubs and grow to a limited height, whereas shrubs are larger and have a more substantial structure.
2. Structure: Herbs have non-woody stems that die back to the ground each year, whereas shrubs have persistent woody stems that support the plant and provide structure.
3. Leaves: Herbs typically have leaves that are fragrant or flavorful and are used for culinary or medicinal purposes, while shrubs have leaves that are often larger and less fragrant.
4. Flowers and fruits: Both herbs and shrubs can produce flowers and fruits, but the size and type of flowers and fruits can be different. Herbs often have small, delicate flowers, while shrubs often have larger, showy flowers.
5. Life cycle: Herbs can be annual, biennial, or perennial, meaning that they live for different lengths of time. Shrubs are typically perennial, meaning that they can live for many years.
6. Uses: Herbs are often used for culinary, medicinal, or aromatic purposes, while shrubs are used as ornamental plants, for wildlife habitat, and erosion control.

Conclusion

Herbs are defined as non-woody plants that are valued for their aromatic or flavorful leaves, stems, flowers, or other parts. The growth and survival of herbs shrubs can be influenced by a variety of factors, including light, temperature, water, and soil nutrients. Herbs play important roles in various ecosystems, serving as food for pollinators, providing habitat for wildlife, and contributing to soil health. Shrubs play important roles in many ecosystems, providing food and habitat for wildlife, stabilizing soil, and helping to maintain biodiversity. 

 

Frequently Asked Questions 

1. What are climbers?

Climbers are a type of plant that have stems that grow vertically and need support to reach the sunlight. Climbers are also known as vines and they are characterized by their ability to attach themselves to other structures, such as trees, fences, or walls, to reach the light they need to grow and flourish.

2. What is called uprooting?

Uprooting refers to the removal of a plant from the ground, along with its roots. This can be done for a variety of reasons, such as to relocate the plant, eliminate unwanted plants from a garden or landscape, or clear land for construction or farming purposes.

3. What are herbs, shrubs and trees with examples?

Herbs, shrubs, and trees are all types of plants that can be distinguished based on their size and structure.

• Herbs are small, non-woody plants that die back to the ground after flowering. Examples of herbs include basil, mint, cilantro, and rosemary.
• Shrubs are larger than herbs but smaller than trees, and they have multiple stems that are woody and persist above the ground. Examples of shrubs include azaleas, hydrangeas, and rhododendrons.
• Trees are large, woody plants that have a single, continuous stem, or trunk, that supports branches and leaves. Examples of trees include oak trees, maple trees, and apple trees.

 

Introduction

Herbivores and carnivores are two types of organisms that differ in their dietary habits and adaptations. Herbivores are animals that feed mainly on plants, such as leaves, stems, and roots. Carnivores, on the other hand, are animals that feed mainly on other animals. Together, herbivores and carnivores form a complex and interconnected web of life, with each playing an important role in the balance of ecosystems.

Herbivores 

Herbivores feed on plant-based diets and have adaptations in their digestive systems to process tough plant matter and extract nutrients. Some common examples of herbivores are rabbits, cows, horses, elephants, giraffes, deer, and gorillas.

Some common adaptations of Herbivores are:

• Large digestive tract: Herbivores have a large and complex digestive tract that helps to break down tough plant fibers and extract nutrients.
• Mouth structures: Some herbivores have specialized mouth structures, such as flat molars for grinding plant material, or sharp incisors for clipping leaves.
• Fermentation: Many herbivores have a fermentation chamber in their digestive tract where microbes break down tough plant fibers and release nutrients.
• Specialized enzymes: Herbivores produce enzymes, such as cellulase and pectinase, to break down plant cell walls and release the nutrients inside.
• Food storage: Some herbivores have adaptations to store food, such as large cheek pouches, to allow them to gather and process large quantities of plant matter at once.

Types of Herbivores 

Herbivores can be classified based on the type of plants they consume and the adaptations they have developed to obtain nutrients from those plants. Some common classifications are:

1. Grazers: Herbivores that feed mainly on grasses and other low-lying plants, such as cows, horses, and sheep.
2. Browse Herbivores that feed on leaves, twigs, and branches of woody plants, such as deer and rabbits.
3. Folivores: Herbivores that feed mainly on leaves, such as elephants and some species of monkeys.
4. Frugivores: Herbivores that feed mainly on fruits, such as bears and some species of monkeys.
5. Nectarivores: Herbivores feed mainly on nectar from flowers, such as hummingbirds and bats.
6. Granivores: Herbivores that feed mainly on seeds, such as squirrels and some species of birds.

Carnivores 

Carnivores are animals that feed mainly on other animals, including both vertebrates and invertebrates. They are characterized by their sharp teeth and strong jaws, which are adaptations for hunting and killing prey. Some common examples of carnivores include lions, tigers, wolves, foxes, and hawks. Carnivores play an important role in maintaining the balance of ecosystems by controlling the populations of their prey species.

They have adaptations in their anatomy and behavior that allow them to hunt and feed on other animals effectively. 

Some common adaptations are:

• Sharp teeth and strong jaws: Carnivores have sharp teeth and strong jaws that are adapted for cutting, tearing, and chewing meat.
• Keen senses: Carnivores have highly developed senses, such as vision, hearing, and smell, which they use to locate and track prey.
• Speed and agility: Many carnivores are fast runners or able to make sudden, powerful movements, which are adaptations for chasing and capturing prey.
• Camouflage: Some carnivores have fur or feather patterns that help them blend into their surroundings and stalk prey unnoticed.
• Hunting behavior: Carnivores have evolved behaviors, such as ambush hunting, cooperative hunting, and pack hunting, that allow them to capture prey efficiently.

Types of carnivores

Carnivores can be classified based on their anatomy, behavior, and diet. Some common classifications are:

1. Feliformia: This group includes carnivores with a cat-like appearance, such as cats, hyenas, and mongooses. They have a short snout, powerful jaw muscles, and retractable claws.
2. Caniformia: This group includes carnivores with a dog-like appearance, such as dogs, foxes, bears, and weasels. They have a longer snout, large jaw muscles, and partially retractable claws.
3. Pinnipeds: This group includes marine carnivores, such as seals, sea lions, and walruses. They have adapted to life in the water, with specialized flippers and a thick layer of blubber for insulation.
4. Birds of prey: This group includes birds that hunt and feed on other animals, such as eagles, hawks, and owls. They have sharp talons, strong beaks, and excellent vision and hearing.

These classifications are based on morphological and behavioral adaptations that reflect the lifestyles and dietary habits of each group of carnivores.

Differences between Herbivores and Carnivores

Herbivores and carnivores are different in several ways, including their anatomy, behavior, and diet.

1. Diet: Herbivores feed mainly on plants, while carnivores feed mainly on other animals.
2. Teeth and jaws: Herbivores have flat molars for grinding plant material, while carnivores have sharp teeth and strong jaws for tearing and chewing meat.
3. Digestive system: Herbivores have longer intestines and complex gut flora to help break down plant material, while carnivores have a shorter intestines and simple gut flora to process animal flesh quickly.
4. Adaptations for obtaining food: Herbivores have adaptations for obtaining and digesting plants, such as long necks for reaching high branches or large incisors for cutting tough vegetation, while carnivores have adaptations for hunting and killing prey, such as sharp claws and strong jaws.
5. Role in the ecosystem: Herbivores play an important role in maintaining the balance of ecosystems by consuming plants and spreading their seeds, while carnivores control the populations of other species and maintain the balance of the food chain.

These differences reflect the adaptations that herbivores and carnivores have developed to obtain the nutrients they need from their respective food sources.

Conclusion 

Herbivores and carnivores are two types of organisms that differ in their dietary habits and adaptations. Herbivores are a type of animal that feeds mainly on plants and plant-based materials. Carnivores have adaptations in their anatomy and behavior that allow them to hunt and feed on other animals effectively. These differences reflect the adaptations that herbivores and carnivores have developed to obtain the nutrients they need from their respective food sources.

 

Frequently Asked Questions 

1. What do you mean by omnivores?

An omnivore is an organism that eats both plant and animal matter, including both organic and inorganic substances. Omnivores have a diverse diet and are able to adapt to a range of food sources

2. What is the relationship between carnivores and herbivores?

Herbivores play a crucial role in the food chain by serving as the primary consumers, converting plant matter into energy and nutrients that can be used by other organisms. They provide a source of food for carnivores and omnivores higher up the food chain and also help to maintain the balance of ecosystems by consuming and spreading the seeds of plants, contributing to their growth and diversity.

3. What do you understand about carnivorous plants?

Carnivorous plants are a group of plants that have evolved to capture and digest insects and other small animals as a source of nitrogen and other nutrients, due to their growth in nutrient-poor soil. Some of the most well-known carnivorous plants include Venus flytrap, pitcher plants, and sundews.

 

Introduction

The fundamental building block of life, a cell is capable of carrying out every metabolic task required to maintain life. A cell must be able to permit the passage of various substances into and out of its boundaries in order to be able to perform the metabolism of various substances. A cell can take in and release substances out of the cell, through the process of diffusion and osmosis. This exchange is essential for the cell’s survival. The processes of molecules moving down a concentration gradient are diffusion and osmosis. Although they both aid in the movement of substances through the cell membrane, they differ slightly from one another.

Diffusion

• The spontaneous movement of a molecule down a concentration gradient is called diffusion. For example- diffusion is the spreading of a dye in water.
• It is referred to as a passive process because it doesn’t require any energy input.
• Concentration gradients and the random dynamic movement of the solute molecules are the only factors that influence diffusion.
• Diffusion keeps going until there is equilibrium i.e until there is an equal concentration of the solute on both sides.
• Diffusion happens through a plasma membrane in biological systems.

Types of diffusion

There are two types of diffusions which are explained below

• Simple Diffusion-
  • Simple Diffusion is also known as Independent Diffusion. 
  • This type diiffusion does not require the involvement of membrane proteins.
  • The relative concentration of the molecules inside the cell as compared to outside the cell determines the direction of the flow of the molecules.
  • Simple diffusion is non-selective and permits the passage of all non-polar molecules across a lipid bilayer.
• Facilitated Diffusion

• • Some molecules cannot move across the cell membrane due tu their hydrophilicity.
  • Thus, the movement of such molecules and charged ions is mediated by certain membrane proteins. This process is termed facilitated diffusion.
  • The channel proteins and the carrier proteins are the two different types of membrane transport proteins.
  • Polar and charged molecules can cross the cell membrane through the process of facilitated diffusion.

Factors affecting rate of diffusion

• Partition Coefficient-It represents the ratio of a solute’s concentration in two phases when both the phases are in equilibrium with one another. The greater the solubility of a solute, the greater will be its partition coefficient.  A substance can pass a biological membrane more readily if its partition coefficient is larger.
• The concentration of the solutes-Fast diffusion occurs when the concentration gradient is higher.
• Temperature- The molecules’ kinetic energy is increased by an increase in temperature, which causes them to travel more quickly across the membrane.
• Mass-Heavier solutes diffuse slowly as compared to lighter solutes.
• The density of the solvent- As solvent density rises, the rate of diffusion declines.
• Nature of the solutes- Lipophilic and non-polar compounds can easily cross the plasma membrane as compared to hydrophilic and polar compounds.

Osmosis 

• Osmosis is the process by which solvent molecules move down a concentration gradient and across a semipermeable membrane (i.e., higher to lower concentration). 
• It is the net movement of solvent molecules from a high water potential region to a low water potential region. 
• Osmosis results in equal solute concentrations on both sides of the membrane.
• The transfer of water from locations with high water potential to those with low water potential is also termed osmosis.

Tonicity

Pertaining to the proportional solute concentrations of a cell and its surroundings there are three different tonicities, they are-

• If a cell is placed in a hypertonic environment, that is, an environment in which the solute is present at a higher concentration than within the cell, the water travels out of the cell and into the surrounding environment.  This causes the cell to lose volume and become flaccid. Plasmolysis, a severe condition in which the cell membrane separates from the cell wall and ruptures.
• Water moves into the cell and causes it to swell if the external environment is hypotonic, that is, if the environment has a lower concentration of solute than the cell. Here, the cell gets turgid.
• There is no net change in the volume of the cell if the external environment is isotonic, or if it contains the same number of solutes per litre of solution as the interior of the cell.

Osmolarity 

• The number of solute molecules per litre of the solvent is referred to as osmolarity.
• Simply said, osmolarity is a measurement of the amount of solute in the solution.
• As a result, referring to a solution as having low osmolarity suggests that its solute concentration per liter of solution is lower. 
• In biology, a cell’s osmolarity is crucial in determining how easily water can move through a bilayer.
• If a semipermeable membrane is used to separate two solutions with differing osmolarities, water from the solution with the lower osmolarity will pass through the membrane and into the solution with the greater osmolarity.

Difference between Osmosis and Diffusion  

Summary 

• The spontaneous movement of molecules along a concentration gradient is known as diffusion.
• In biological systems, diffusion across the cell may be independent or facilitated by membrane proteins
• Osmosis is the transfer of solvent molecules across a semi-permeable membrane along a concentration gradient.
• Osmosis and diffusion vary primarily in that the former takes place through a semi-permeable membrane while the latter can happen in any medium.

 

Frequently Asked Questions

1. What is Osmotic Pressure?

Ans: Osmotic pressure is the amount of force required to stop solvent molecules from passing through a semipermeable membrane into a solution. Temperature and concentration both have an impact on osmotic pressure. Osmotic pressure rises as concentrations and temperatures rise.

2. What are channel proteins?

Ans: A channel protein is a type of transport protein that functions as a pore in the cell membrane to allow water molecules or small ions to pass through. Aquaporins, which are water channel proteins, enable rapid water diffusion across the membrane. Ions can diffuse across the membrane through ion channel proteins.

3. Give two examples of osmosis and diffusion each.

Ans: Red blood cells’ enlargement when exposed to freshwater, and absorption of water by plant root hairs are examples of osmosis

The fragrance of perfume spreading throughout a room and the passage of tiny molecules across a cell membrane are both examples of diffusion.

Introduction

The closed circulatory system of higher animals,  such is made up of various blood vessels. The blood vessels make sure that every cell throughout the body receives an uninterrupted flow of oxygen-rich blood from the heart. The blood vessels have been specifically designed to carry one of the two types of blood-i.e oxygenated or deoxygenated blood to prevent their mixing. Deoxygenated blood is carried by the veins and venules, whereas oxygenated blood is carried by the arteries and arterioles. The third type of blood vessel, capillaries, are the smallest divisions and enable exchange between the blood and tissues.  The blood vascular system is separated into two circuits: the systemic circuit, which provides healthy blood to the entire body, and sends impure blood to the heart, and the pulmonary circuit, which works between the heart and the lungs.

Arteries

• Blood is pumped from the heart through arteries and then into the body.
• The systemic arteries follow a path that starts in the left ventricle and travels through smaller distributions to every portion of the body.
• As a result, arteries play a crucial role in supplying the organs with blood and nutrients.
• Up to 10% of the blood in the body is stored in arteries at any given moment.
• Only one artery in the body, the pulmonary artery of the pulmonary circuit, transports deoxygenated blood from the heart’s right ventricle to the lungs.
• The three layers of tissue that make up an arterial vessel—the tunica interna, tunica media, and the tunica externa/tunica adventitia—can vary in composition depending on the particular artery.
• The middle layer of the arterial wall, known as the tunica media, is the thickest layer and controls blood pressure by adjusting the vessel’s diameter.
• The type of vessel and the tasks it performs have a significant impact on the tunica media’s internal composition.

Types of Arteries and their Functions 

There are three types of arteries. They are as follows-

• The Elastic Arteries
  • They are the biggest and the closest to the heart; they are also referred to as conduit arteries. Examples include the aorta and the pulmonary arteries.
  • The tunica media is strengthened by a lot of collagen and elastin to accommodate the blood surge since they get blood directly from the heart.
  • As the heart beats, the artery walls can easily stretch because of elastin.
  • Elastin also aids in keeping the pressure in the arteries constant.
  • The elastic arteries buffer the cyclic changes that occur in the arterial blood pressure.
  • The collagen fibers of the arterial wall bear the mechanical load at higher stresses, while the elastin fibers handle the low-pressure wall stretches.
• The Muscular Arteries

• • The larger elastic arteries give rise to these medium-sized blood vessels.

More amount of smooth muscles and a reduced amount of elastin fibers are present in the tunica media of muscular arteries.

• These arteries are distributing arteries, which means they transport blood from the elastic arteries to the body’s organs and other regions.
• Actomyosin-mediated contractions and relaxations cause the smooth muscles in the tunica media to contract or relax as necessary. This helps in narrowing or expanding the arterial lumen to control blood pressure.
• Examples include the femoral artery, brachial artery, and radial artery.

• Arterioles

• • These are the smallest of the arterial blood vessels, with an average internal diameter of only 30 𝝁m.
  • Typically, there are only 1-2 layers of smooth muscles in the walls of these arterioles. 
  • Their primary duty is to transport blood to the capillaries from the major arteries.
  • Due to its reduced diameter, which resists blood flow, arterioles serve as vascular resistors and control blood flow and blood pressure.
  • They are also referred to as resistance vessels.

Veins

• The blood vessels known as veins are responsible for transporting tissues’ deoxygenated blood back to the heart for the purpose of reoxygenation.
• In the venous system, blood enters the venules from the capillaries, moves through the major veins, and eventually arrives at the heart. This is in contrast to blood flow occurring in the arteries.
• Up to 70% of the blood in the body is stored in the veins at any given time.
• The pulmonary veins bring oxygen-rich blood from the lungs to the heart, whereas the systemic veins transfer deoxygenated blood to the right atrium.
• The three layers of tissue that make up an veins are the tunica interna, tunica media, and the tunica externa/tunica adventitia.
• However, due to the decreased blood pressure, the diameter and number of smooth muscles in the veins are fewer.
• Due to the lower blood pressure that is flowing through them, the diameter and number of smooth muscles have decreased.
• Vein have valves that ensure blood flow in a forward direction only.

Types of Veins

• Systemic veins

• • These veins transport blood from the bodily tissues to the right atrium since they are a part of the systemic circuit. 
  • The largest vein in the body, the vena cava, drains blood to the right atrium from both the lower and upper parts of the body.

• Pulmonary veins 

• • These veins are connected to the pulmonary circuit, which connects the heart and lungs.
  • They deliver oxygenated blood from the lungs to the left atrium of the heart.
  • Two pulmonary veins come from each lung, hence there are a total of 4 pulmonary veins.

• Superficial Veins

• • These veins are numerous and located close to the skin’s surface.
  • Examples: Saphenous veins, cephalic veins, basilic veins, etc.

• Deep Veins
  • These veins are located deep inside the muscular tissues, and a systemic artery is present adjacent to them. For instance, the brachial vein lies next to the brachial artery, while the femoral vein lies next to the femoral artery.

• Venules

• • These are the body’s tiniest veins, and they are responsible for transporting deoxygenated blood from capillaries to the major veins.

Difference between Arteries and Veins

Summary

• The cardiovascular system consists of an effective network of three different types of blood vessels, each with distinct purposes.
• The arteries transport blood rich in oxygen from the heart to the rest of the body.
• There are three different types of arteries: elastic arteries, muscular arteries, and arterioles.
• Veins can be deep-seated or superficial, and they return deoxygenated blood from the body to the heart.
• For every artery that supplies blood to an area, there is a corresponding vein that carries blood away.

Frequently Asked Questions

1. What color of blood is present in veins?

Ans: Blood present in the body is red in color. It is bright red when it has received oxygen i.e. while flowing through the arteries and dark red when it has lost oxygen i.e while flowing through the veins.

2. What are the 4 main arteries of the heart?

Ans: The four main arteries of the heart are- 

• The right coronary artery
• The left main coronary
• The left anterior descending
• The left circumflex artery

3. What are the components of tunica adventitia?

Ans: The outermost tunica (layer) of a blood vessel, encircling the tunica media, is called the tunica externa , also referred to as the tunica adventitia. It is mainly made up of collagen.In arteries, it is supported by external elastic lamina.

Introduction

An allele is a variation of a certain gene. It is an alternative form of a gene. William Bateson and Edith R. Saunders  coined the word “allele“. Alleles were originally known as “allelomorphs”. These paired copies of the same gene convey information for the expression of the same characteristics, yet they have distinct effects on people within a population. Alleles are always located at the same location on a chromosome. On homologous chromosomes, alleles of a gene occupy corresponding locations. Alleles are part of DNA and hence they are made up of a deoxyribose sugar, a nitrogen base and phosphate group.

Types of alleles

There are two types of allele found, they are as follows-

Homozygous alleles- These are identical alleles on a diploid organism’s chromosome. The organism is referred to as homozygous recessive for that particular trait if both alleles are recessive (aa). In contrast, a person could be homozygous dominant, if  they have both dominant alleles.

Heterozygous allele– These refer to an organism that has two distinct alleles at a same locus on a chromosome. In this case one allele establishes dominance (known as the dominant allele) and is expressed while the other allele (known as the recessive allele) is not expressed.

Functions of  alleles

Following are the function of a allele

• The various alleles define the various “traits” of a particular character.
• The external phenotype of an organism is determined by the inherited alleles.
• The observable traits are determined by interactions between alleles.
• Alleles encode for improtant proteins, that are necessary for the survival of an organisms.
• Mutations in alleles can be fatal or can lead to conditions such as CFTR, Achondroplasia, Sickle Cell Anaemia, etc.

Difference between gene and allele

Summary 

An organism’s genetic makeup determines all of its traits, including its physical and metabolic properties. An allele is a gene’s alternate form with minute sequence variations. On homologous chromosomes, the allele(s) for a particular gene are always found at the same locus. A gene’s allelic variants enable more diverse detectable phenotypes among organisms. This leads to more genetic diversity in various species. Different hair colour, eye colour, skin pigmentations, etc seen in the population is due to the alleles for these respective traits. Genetic illnesses like Cystic fibrosis, Huntington’s disease, Sickle cell anaemia, thalassemia, etc. can be caused due to  mutations present in various alleles.

 

Frequently Asked Questions

1. What is a gene?

Ans: Genes are the functional unit of heredity that determine an organism’s unique features and are transmitted from parents to offspring or daughter cells.The term gene was coined by Wilhelm Johannsen in 1905.It encodes RNA and polypeptides that have an impact on the organism’s overall makeup.Any organism’s appearance, behaviour, and metabolism are critically impacted by gene expression.

2. What are multiple alleles?

Ans: In a group of organisms or species, there may be more than two distinct gene forms, which are referred to as multiple alleles. Although the genotype of the population’s members still only contains two alleles, each person may have a different set of alleles.

3. How many alleles per gene are there in humans?

Ans: Since humans are diploid organisms, each genetic locus contains two alleles for each gene. During  gametogenesis these alleles divides into different chromosomes. Following fertilisation, the zygote obtains two copies of every gene, one from each parent. These copies may or may not be similar.

Introduction

Hormones are chemical substances that are released by ductless glands directly into the bloodstream. Although they are immediately released into the blood, only their intended target organs are affected. There are various hormones present in the body and all of them are controlled by the hypothalamus and hence it is known as the master gland. Adrenocorticotropic hormone, or ACTH, also known as corticotropin is synthesized  and secreted by the anterior pituitary gland and its targets are the adrenocortical   cells in the adrenal gland. It is responsible for the release of  glucocorticoid hormones, some sex hormones, and various other cellular pathways.

Synthesis

Synthesis of the ACTH hormone takes place in the basophilic cells of the anterior pituitary gland. It is generated from a molecule known as Pre-proopiomelanocortin or pre-POMC. This molecule signals the formation of a 241-amino-acid polypeptide POMC. This POMC undergoes various translational modifications and is ultimately cleaved by endopeptidases which yield a variety of polypeptide fragments including ACTH hormone.

Control mechanism

• The hypothalamus, the adrenal gland, and the pituitary gland are collectively known as the  hypothalamic-Pituitary-Adrenal axis and are responsible for the secretion of ACTH in the body.
• Low levels of cortisol in blood– When the level of blood cortisols are lower than normal, then the hypothalamus is triggered and it secretes corticotropin releasing hormone which in turn signals the pituitary gland to release ACTH in blood.
• High levels of cortisol in blood- The elevated levels of cortisols in the blood is detected by adrenal gland receptors. This increased level of hormone inhibits the secretion of corticotropin releasing hormone, which in turn reduces the secretion of ACTH from the pituitary gland. This process is known as the negative feedback mechanism and is responsible for maintaining the blood cortisol levels in the body.

Functions

ACTH in the body has various important functions such as-

• ACTH  stimulates  the adrenal cortex for production hormones, particularly glucocorticoids.
• It helps in the uptake of lipoproteins which in turn increases the availability of cholesterol in the adrenal cortex cells.
• It helps in the regulation of metabolism, bone reabsorption, protein catabolism, hyperglycemia and lipolysis.
• It also stimulates the secretion of other hormones for the synthesis of androgens which aids in spermatogenesis.
• ACTH release activates the  adenylyl cyclase enzyme in the cell membranes which produces cAMP, this cAMP is used in various cellular pathways.

ACTH Disorders

ACTH disorders occur due the presence of tumours near the pituitary glands, malfunctioning of the adrenal gland, congenital diseases, hypopituitarism, genetic or hereditary disorders etc.

Excess of ACTH causes- 

• Obesity in the upper body. 
• Accumulation of fat near throat region
• Stretch marks, in abdomen, thigh etc.
• Men’s diminished libido and women’s irregular menstrual cycles.

Low level of ACTH cause-

• Anorexia, or a loss of appetite.
• In the affected people, low blood sugar and potassium levels may be seen.
• Females may notice less hair growth in the pubic and armpit areas.
• Different emotional reactions such as depression and psychosis are observed.

Summary

From the above article, we learn about the synthesis of ACTH, its functions, and the diseases brought on by the body’s inappropriate amounts of this hormone. The aforementioned parts teach us about the importance of the ACTH hormone. It is a crucial hormone that triggers the release of other essential adreno-cortical steroid hormones, such as cortisol, which is in charge of the body’s metabolism and particularly the body’s reaction to stress.

Frequently Asked Questions

1. Define catabolism and anabolism.

Ans: The process of converting complex molecules into simpler ones is referred to as catabolism. Energy is eventually released from the process. On the other hand, anabolism entails the joining of smaller molecules to create a larger and more complicated molecule. Energy is required for this procedure.

2. Give the two main types of hormones found in the human body?

Ans: In general, there are two sorts of hormones.Peptide hormones -they are made of amino acids and are soluble in water. For eg-Insulin.Steroid hormones that are fat soluble are the second category. Examples include sex hormones.

3. What is produced by the medulla of the adrenal gland?

Ans: Adrenaline and noradrenaline, are the main hormones secreted by the medulla area of the adrenal gland,and which are involved in the body’s flight or fight response.

Introduction

Antidiuretic hormone (ADH), also known as vasopressin or arginine vasopressin, is generated in the brain and stored in the posterior pituitary gland. It primarily regulates fluid output of the body by allowing the kidneys to reabsorb water during the process of  ultrafiltration of blood. It is known as a nonapeptide since it is a peptide hormone made up of nine amino acids. The hypothalamus’s osmoreceptors detect the blood’s high solute concentration (high solute is an indication of low fluid) and indicate the release of ADH hormone.

Functions

The functions of ADH hormone are as follows-

• Diuretic refers to substances that can increase the water content in the urine. ADH, an antidiuretic hormone, lowers this water content during urine production.
• ADH action allows the  reabsorption of water from the collecting tubules by increasing their permeability towards water.As a result, it only permits very little urine to leave the body.
• ADH contributes to maintaining the homeostasis of the body, necessary for healthy cellular activity.
• ADH causes blood arteries to contract, which raises blood pressure.Blood flows with higher pressure because of constriction of the lumen of the blood arteries.

Regulation

ADH is regulated by the hypothalamus, the master gland.

• The baroreceptors found in blood vessels close to the heart transmit information to the brain in cases of severe blood loss caused by blood vessel damage that results in a brief state of hypovolemia.
• During Summertime there is a high solute concentration in the blood. This occurs because of the heavy sweating and extremely high daytime temperatures.
• This situation is detected by osmoreceptors in the hypothalamus, which alerts the brain to it to maintain a healthy cellular environment.
• For this, the brain instructs various hormones in the body which will help to prevent water loss.
• Low fluid and high solute levels cause the posterior pituitary gland to release the ADH hormone. This hormone acts on nephrons in the kidneys specifically,  the collecting ducts and thus allowing water retention. 

Disorders

Hypothermia

• It develops when the body secretes too much ADH, which causes the kidneys to retain more water while salts continue to be eliminated normally from the body. 
• This leads to a cellular condition known to have low salt concentration and high fluid content (low sodium in the bloodstream) arises which is also known as hypothermia.
• This condition  might result from a tumour of some kind that releases excess of ADH in the body.
• Drug side effects may also cause this disease to develop.

Central Diabetes insipidus-

• When ADH levels fall below the normal range, water retention is inhibited.
• This is so, because the collecting ducts become  water-impermeable and as a result, discharged urine which has a high fluid content.
• Such a condition is known as Central diabetes insipidus.
• This may occur as a result of infection, inflammation,injury ,surgery or brain trauma,  in the hypothalamus, or the posterior pituitary gland or both of them.

Nephrogenic Diabetes Insipidus-

• Nephrogenic diabetes insipidus develops when the kidneys become resistant to ADH, either as a result of signal mediator or nephron receptor malfunction.
• This disease occurs because even though ADH is readily available, it cannot bind to the target site and carry out its metabolic function.

Summary

Through the consumption of meals and liquids, the body receives water continuously. While some water is lost by perspiration through the skin, the majority is excreted as urine. The continuation of life processes depends on the maintenance of the water balance. This water balance in the body is maintained by ADH-Antidiuretic hormone which helps in water retention in the body and maintains the steady state of the body.

Frequently Asked Questions

1. What are edema and dehydration?

Edema is the condition of excessive water retention. Dehydration is excessive water loss or very little water intake. Neither of these states is an indication of a healthy person.

2. What is difference between diabetes Diabetes insipidus and diabetes mellitus?

Low ADH levels cause the polyuria and polydipsia condition known as diabetes insipidus. High blood glucose levels brought on by inadequate pancreatic insulin secretion are known as diabetes mellitus.

3. How can alcohol consumption affect ADH?

The secretion of ADH is inhibited by alcohol intake. This causes an increased urine production and dehydration in the body. It leads to symptom of severe headaches.

Introduction

Biodegradable and non-biodegradable substances refer to the materials that make up the products and waste we use and discard in our daily lives. Biodegradable substances are made from organic materials and have a positive impact on the environment when properly managed and disposed of. Non-biodegradable substances, on the other hand, are made from synthetic materials and do not break down in the natural environment. It is important to minimize our use of non-biodegradable substances and properly manage both biodegradable and non-biodegradable waste in order to protect the environment and promote sustainability.

Biodegradable Waste and Biodegradable Material

Biodegradable waste materials are materials made from organic matter, such as starch-based plastics or plant-based fibers, which can be broken down by natural processes into the water, carbon dioxide, and biomass. Unlike traditional plastics, which can persist in the environment for hundreds of years.

Examples of Biodegradable substances

Some common examples of biodegradable substances include:

• Food waste, such as fruit and vegetable scraps, bread, and meat
• Yard waste, such as leaves, grass clippings, and tree branches
• Paper products, such as newspaper, paper towels, and cardboard
• Textiles made from natural fibers, such as cotton or wool
• Biodegradable plastics made from renewable materials, such as corn starch or sugarcane
• Manure and sewage sludge
• Wood chips and sawdust.

Non-Biodegradable Waste and Non-Biodegradable Material

Non-biodegradable material refer to a material that does not break down into natural substances over time and persist in the environment for long periods. These materials are typically synthetic, made from petrochemicals, and do not decompose in the natural environment.

Non-biodegradable waste refers to discarded items made from non-biodegradable materials that cannot be decomposed by natural processes. Examples of non-biodegradable waste include plastic bags, polystyrene packaging, and aluminum cans. Unlike biodegradable waste, non-biodegradable waste can persist in the environment for hundreds of years and can cause environmental problems if not properly disposed of.

Examples of Non-Biodegradable substances

Some common examples of non-biodegradable substances include:

• Traditional petroleum-based plastics, such as polyethylene (PE) and polypropylene (PP)
• Aluminum cans and foil
• Glass bottles and jars
• Metal products, such as steel cans and car parts
• Electronic waste, such as computers, phones, and televisions
• Synthetic fibers, such as nylon and polyester
• Certain types of synthetic rubber and paints
• Fire retardants and flame-retardant materials.

Effect of Biodegradable and Non-Biodegradable Substances on the environment 

The effects of biodegradable and non-biodegradable substances on the environment can vary greatly.

• Biodegradable substances, such as food waste and yard waste, can have positive impacts on the environment when properly managed. For example, food waste can be composted and added to soil as a natural fertilizer, improving soil health and reducing the need for chemical fertilizers. Yard waste can also be composted, or used as mulch to retain moisture in the soil.
• On the other hand, non-biodegradable substances can have harmful impacts on the environment. When not properly disposed of, non-biodegradable waste, such as plastic bags and polystyrene packaging, can litter the environment, harm wildlife, and take hundreds of years to break down. Landfills overflowing with non-biodegradable waste can also release toxic substances into the air and water, causing further harm to the environment and human health.
• In addition, the production of non-biodegradable materials, such as petroleum-based plastics, can contribute to greenhouse gas emissions and other environmental problems associated with the extraction and processing of fossil fuels. 
• When these wastes build in the soil, they affect the pH and fertility of the soil. Non-biodegradable trash should be reused, reduced, or repurposed rather than dumped into oceans, as this constitutes a significant environmental risk.

Overall, it is important to properly manage both biodegradable and non-biodegradable substances in order to minimize their negative impacts on the environment.

Differences between biodegradable and non-biodegradable substances:

Conclusion

Biodegradable compounds are those that can be broken down or decomposed by the action of microbes or any form of life, whereas non-biodegradable substances are those that cannot be broken down into little pieces by the action of any kind of life. Organic wastes that degrade quickly are considered biodegradable wastes. Plastics and glassware are examples of non-biodegradable garbage that require thousands of years to disintegrate. All sorts of garbage affect our environment and all types of life on the planet. As a result, waste treatment is critical, which includes recycling, reusing, and decreasing.

 

Frequently Asked Questions 

1. What is the three R’s stand for?

The “Three R’s” stand for Reduce, Reuse, and Recycle. They are a widely recognized hierarchy of waste management and sustainability that encourages individuals and organizations to minimize waste and promote sustainability by reducing their consumption of resources, reusing products and materials whenever possible, and recycling materials that cannot be reduced or reused.

2. What is a biodegradable polymer?

A biodegradable polymer is a type of plastic that is designed to break down and decompose into natural substances over time through the action of microbes, heat, and other environmental factors. Biodegradable polymers are typically made from renewable resources, such as plant-based materials, and are designed to be more environmentally friendly than traditional petroleum-based plastics.

3. What is biodegradable degradation?

Biodegradable degradation refers to the process of breaking down and decomposing organic material into natural substances through the action of microbes, heat, and other environmental factors. This process is a natural and essential part of the earth’s ecosystem and helps to recycle nutrients and other substances in the environment.

Introduction

Haploid and diploid indicate the set of chromosomes in a cell or organism. Haploid refers to half the number found in the typical diploid cells of the same species and are typically found in gametes (eggs or sperm) or certain single-celled organisms. They contain a single set of genetic information, which can be beneficial for processes such as reproduction and genetic variation. This genetic diversity allows the way for adaptation and evolution.

What is a haploid?

A haploid set of chromosomes refers to the complete set of chromosomes presents in a single gamete or sex cell (sperm or egg). It is a single set of chromosomes that results from the reduction division (meiosis) of a diploid cell (with two sets of chromosomes) into four haploid cells. The haploid number of chromosomes in a species is designated as “n”. 

• A common example of a haploid set of chromosomes is found in human sperm or eggs, which contain 23 chromosomes each. This results from the reduction division (meiosis) of diploid cells (which contain 46 chromosomes, or two sets of 23 chromosomes each) into haploid cells. 
• In other species, the haploid number can vary. For example, in fruit flies (Drosophila melanogaster), the haploid number is 8, while in wheat (Triticum aestivum), it is 7.
• Since haploid cells have a single set of chromosomes, each gene has only one allele. It means that each gamete has just one allele for a given gene, and when two gametes (male and female) fuse, two alleles of the gene combine and express their phenotype based on the dominant recessive interaction.

What is diploid?

Diploid refers to a cell or organism that has two sets of chromosomes. The diploid number of chromosomes is designated as “2n” in a species, where “n” is the haploid number of chromosomes (the number present in a single set). Each chromosome is present in pairs in diploid cells, with one chromosome from each parent. A diploid set of chromosomes is the typical number found in most body cells of an organism, as opposed to the haploid set found in gametes or sex cells (sperm and egg).

Diploid cells have two sets of chromosomes, which provide stability to the genetic material and ensure that each cell has a complete set of chromosomes. This stability is essential for normal cell function and proper cell division.

Role in Division of cells

• Mitosis and meiosis are cell division processes that are related to the concept of haploid and diploid cells.
• In mitosis, a single diploid cell (2n) divides into two identical diploid daughter cells, each with the same number of chromosomes as the parent cell (2n). This type of cell division is used for the growth and repair of tissues in multicellular organisms.
• In meiosis, a single diploid cell (2n) undergoes two rounds of division, resulting in the formation of four haploid daughter cells (n). Meiosis is involved in the creation of haploid gametes for sexual reproduction. The reduction in chromosome number from 2n to n ensures that when the gametes fuse during fertilization, the resulting zygote has the normal diploid number of chromosomes (2n).
• As a result, mitosis produces identical diploid cells, whereas meiosis produces genetically heterogeneous haploid cells. These processes are important for the maintenance of chromosome number and genetic diversity in multicellular organisms.

Difference between haploid and diploid

The main differences between the two are:

1. Chromosome number: Single set of chromosomes can be seen in a Haploid, while two sets of chromosomes are present in a diploid. The haploid number of chromosomes is designated as “n”, while the diploid number is designated as “2n”.
2. Genetic material: Haploid cells contain half the amount of genetic material as diploid cells. This results in haploid cells having a unique combination of alleles for each gene. On the other hand, diploid cells have two alleles for each gene, one from each parent.
3. Function: Haploid cells are primarily involved in sexual reproduction, as they provide genetic diversity when two haploid cells combine such as sperm and egg they form a diploid cell resulting in a zygote. Diploid cells are found in most organisms, including the human body, and provide stability to the genetic material.
4. Cell division: Haploid cells are produced by meiosis, a type of cell division that reduces the chromosome number by half. Diploid cells can be produced by either meiosis or mitosis, a type of cell division that results in the production of two identical daughter cells.

Conclusion

In eukaryotic species, the genetic components are enclosed within the cell nucleus and are known as chromosomes. The ploidy of an organism is defined by the number of chromosomal sets. Haploid cells are those that have a single set of chromosomes and are generated as a result of meiosis. It is widespread among gametes. Diploids have two chromosomal sets and are produced during mitotic cell division. Although haploid and diploid are distinct, each shares important characteristics.

Frequently Asked Questions 

1. What exactly do you mean by karyotype?

A karyotype is a visual representation of the complete set of chromosomes in a cell and is used to diagnose genetic disorders and chromosomal abnormalities.

2. What effect do chemical mutagens have on polyploidy?

Chemical mutagens can induce changes in the DNA of cells and can lead to polyploidy. Polyploidy, which is the presence of extra sets of chromosomes in a cell, can be caused by errors during cell division, such as failures in meiosis, as well as exposure to environmental factors like radiation and certain chemicals, including mutagens.

3. Is a brain cell haploid or diploid?

Human brain cells are somatic cells. All somatic cells in the human body are diploid, which means they have two copies of each chromosome.

Introduction

A natural resource is any naturally occurring substance that is used to sustain life and satisfy human needs. A wide range of natural resources that we use on a daily basis, are food, water, non-synthetic clothing, timber, metals, oil, coal, natural gas, sunlight, air, soil etc. One must be aware that not all of these resources are open to endless use. These resources should be used judiciously as they are for essential human growth and sustenance. Hence, natural resource management has now become the need of the hour. Natural resource management (NRM) is the collective term for a range of interdisciplinary and comprehensive approaches developed to manage and maintain the natural resources now in use, both for the benefit of the current generation and for future generations. It emphasises the management of land, water, and forest resources as well as the preservation of flora and fauna. 

Approaches to Management of Natural Resources 

The approaches must include the necessary policies, the sustainability of the rules and practises, and the need to recover resources that have already been depleted or are running out. Following are the strategies for Natural resource management:

• Top-down approach: 

• Based on the paternalistic notion that only environment specialists who have practical expertise and sound judgement should plan and implement NRM. Since local input is required for good results in natural resource management, this strategy is frequently unsuitable and unsustainable.

• Community-based approach:

• • • Aggressive farming methods and urbanisation harm people whose livelihoods depend on natural resources, particularly forests.
    • The community-based approach gives local groups a role in developing NRM strategies and conservation projects that directly impact them.
    • Multi-stakeholder partnerships, the creation of powerful local groups, the use of law enforcement to stop unauthorised land invasion, and cooperative management plans are some of the features of the community-based approach.

• Integrated approach

• • • It encompasses a variety of sectors including the public and private organizations.
    • It strives to conserve the environment, provide food security, and decrease poverty.
    • The main goal of this startegy is to make resource management sustainable for all.

• Adaptive approach

• • • This approach addresses the reasons and consequences of using NRM tactics.
    • It incorporates diverse viewpoints, experimentation with social learning, evaluation of progress, testing of policies, detecting knowledge gaps, and improved communication with related people.
    • It ultimately will lead to proper and effective management practices.

• Environmental economics approach: 

• This approach incorporates the use of management tools, such as grants, quotas, licences, rights to property, permits, etc., that are successful in the regulation, monitoring, analysis, and assessment of natural resources.

Sustainable Management

Strategies and practices that combine resource management with sustainable development constitute sustainable management of natural resources. When building long – term sustainable management practises, three factors should be taken into account they are:-

• Current and future requirements
• Ecological preservation
• Financial viability

Effective models and practises that are developed in this way not only conserve resources and maintain sustainability, but also assist in meeting the future needs of these resources.

Methods of Sustainable Management

Agriculture, mining, petroleum, and other industries are all involved in the sustainable management of natural resources.In addition to the five R’s of sustainable management, resource management  includes-

• Integrated Forest Management (IFM)
• Integrated Water Management (IWM)
• Creating sustainable agriculture methods
• Safeguarding coral reefs and coastal mangrove habitat
• Programs for recovering resources from “waste materials”
• Public education and awareness

Summary

• Natural resource management is an integrated, comprehensive strategy for promoting prudent methods for resource utilisation.
• The need for implementation NRM technique has arised due environmental pollution, urbanisation, industrialization, and overpopulation.
• The top-down strategy, community-based approach, adaptive approach, integrated approach, and environmental economics are examples of NRM approaches.
• Natural resources must be handled sustainably while taking into account current and future requirements, environmental protection, and economic viability.
• Effective management requires raising public knowledge and participation, as well as utilising adaptive management techniques.

 

Frequently Asked Questions

1. What is water harvesting?

Water harvesting is the practise of collecting surface runoff or rainwater by building catchments, prevent pollution of the collected water and storing water for later use. In various regions of India, like Rajasthan, Tamil Nadu, etc., it has helped in solving issues such as water scarcity and water shortage.

There are various methods for collecting water:

• Catching runoff from rooftops
• Collection of runoff from nearby catchments
• Seasonal flood water collection
• Watershed management

2. Which sectors are affected due to delpetion natural resources?

Following sectors are affected by the delpetion natural resources-

• The agricultural and forestry sector are most severely impacted. This is because of their reliance on the availability of natural resources directly.
•  Along with ineffective animal husbandry techniques, the depletion of water and soil resources has a direct impact on agricultural output and food availability.
• The diminishing natural resources has impacted the forest communities as well as they depend on the forest produce for food, shelter and financial income.
• In addition to endangering their ability to support themselves, it has also increased the frequency of landslides and soil erosion, which has directly endangered their survival.

3. Inlist the 5 R’s of sustainable management.

The 5 Rs of sustainable management are-

• Reduce
• Reuse
• Recycle 
• Repurpose
• Refuse