FINAL YEAR PAPER 6.1 AND PAPER 6.2 QUESTION BANK

Darwin's Finches: On the Galápagos Islands, a single ancestral finch species diversified into multiple species, each with unique beak shapes and sizes adapted to different food sources.
Hawaiian Honeycreepers: These birds diversified into a variety of species with different feeding habits and beak shapes, exploiting different ecological niches in the Hawaiian Islands.
Cichlid Fish in African Great Lakes: In Lakes Victoria, Malawi, and Tanganyika, cichlid fish have undergone extensive adaptive radiation, resulting in hundreds of species with diverse feeding strategies and morphologies.

2. Define genetic drift and gene pool.

Genetic Drift: Genetic drift is a mechanism of evolution that refers to random changes in the frequency of alleles in a population. This randomness can lead to significant changes in allele frequencies over time, especially in small populations, potentially leading to the loss of genetic variation and fixation of certain alleles.

Gene Pool: The gene pool is the complete set of genetic information within all individuals in a population. It includes all the alleles of all the genes in that population. The gene pool represents the genetic diversity available for evolution and adaptation.

3. Define fossils and mention their types.

Fossils: Fossils are the preserved remains, impressions, or traces of organisms that lived in the past. They provide valuable information about the history of life on Earth and the evolution of organisms.

Types of Fossils:

Body Fossils: These are the remains of the actual organism, such as bones, teeth, shells, and leaves.
Trace Fossils: These include indirect evidence of an organism's presence, such as footprints, burrows, or fecal matter (coprolites).
Molecular Fossils: These are organic molecules that are remnants of ancient life, such as DNA, lipids, or proteins preserved in sediments.
Cast and Mold Fossils: A mold fossil forms when an organism buried in sediment decomposes, leaving an impression. A cast fossil forms when the mold fills with minerals.

4. Distinguish microevolution and macroevolution. Give examples.

Microevolution: Microevolution refers to small-scale changes in allele frequencies within a population over a few generations. These changes are often due to natural selection, genetic drift, mutation, and gene flow.

Examples of Microevolution:

Peppered Moth (Biston betularia): Changes in coloration in response to industrial pollution.
Antibiotic Resistance: Bacteria evolving resistance to antibiotics.

Macroevolution: Macroevolution refers to large-scale evolutionary changes that occur over long geological periods, leading to the emergence of new species, genera, families, or higher taxa. It encompasses major evolutionary transitions and patterns of speciation and extinction.

Examples of Macroevolution:

The evolution of mammals from reptilian ancestors.
The diversification of flowering plants (angiosperms).

5. Enlist patterns of evolution.

Divergent Evolution: When two or more species that share a common ancestor evolve different traits, leading to increased differences over time.
Convergent Evolution: When unrelated species develop similar traits due to adapting to similar environments or ecological niches.
Parallel Evolution: When two related species evolve in similar ways for a long period in response to similar environmental pressures.
Co-evolution: When two or more species reciprocally affect each other's evolution.
Adaptive Radiation: Rapid diversification of a single ancestral species into multiple new species adapted to different environments.

6. Define speciation. Mention the types.

Speciation: Speciation is the evolutionary process by which populations evolve to become distinct species. It involves the splitting of one species into two or more genetically distinct ones.

Types of Speciation:

Allopatric Speciation: Occurs when populations are geographically separated.
Sympatric Speciation: Occurs without geographical separation, often through genetic divergence within the same environment.
Parapatric Speciation: Occurs when populations are partially separated and have a narrow zone of contact.
Peripatric Speciation: A form of allopatric speciation where a small population becomes isolated at the edge of a larger population's range.

7. Distinguish allopatric and sympatric speciation.

Allopatric Speciation:

Geographic Isolation: Populations are physically separated by a barrier (e.g., mountains, rivers).
Gene Flow Interruption: The geographic barrier prevents gene flow between the populations.
Examples: Darwin’s finches on the Galápagos Islands.

Sympatric Speciation:

No Geographic Isolation: Populations share the same habitat.
Genetic Divergence: Speciation occurs through mechanisms such as polyploidy, sexual selection, or ecological differentiation.
Examples: Apple maggot flies (Rhagoletis pomonella) adapting to different host plants.

8. What is cleavage? Mention types.

Cleavage: Cleavage is the series of rapid cell divisions that follow fertilization in early embryonic development, leading to the formation of a multicellular structure known as a blastula.

Types of Cleavage:

Holoblastic Cleavage: Complete division of the egg into smaller cells; common in species with little yolk (e.g., mammals, amphibians).
Meroblastic Cleavage: Incomplete division of the egg, occurring in species with a large amount of yolk (e.g., birds, fish).

9. Define placentation. Name types of placenta.

Placentation: Placentation refers to the formation and type of placenta during the development of mammals. The placenta is an organ that provides nutrients and oxygen to the developing fetus while removing waste products.

Types of Placenta:

Diffuse Placenta: Found in horses and pigs, where the placenta is spread out over a large surface area.
Cotyledonary Placenta: Found in ruminants like cows and sheep, where the placenta attaches at specific points called cotyledons.
Zonary Placenta: Found in dogs and cats, where the placenta forms a band around the fetus.
Discoidal Placenta: Found in humans and rodents, where the placenta forms a disc-shaped attachment.

10. Define metamorphosis and regeneration.

Metamorphosis: Metamorphosis is the biological process by which an animal undergoes a dramatic change in form and function from the larval to the adult stage.

Regeneration: : Regeneration is the process by which organisms repair or replace damaged or lost body parts, allowing for the restoration of structure and function.

11. Define estrous cycle. Name animals adapted for estrous cycle.

Estrous Cycle: The estrous cycle is the reproductive cycle in female mammals (other than primates) during which they go through periods of fertility (estrus or "heat") and non-fertility.

Animals Adapted for Estrous Cycle:

Cows
Horses
Dogs
Cats
Sheep

12. What are homeobox genes?

Homeobox Genes: Homeobox genes are a group of regulatory genes that control the development of structures in various organisms. These genes contain a characteristic DNA sequence known as the homeobox, which encodes a protein domain (homeodomain) that binds to DNA and regulates the expression of other genes during embryonic development.

13. Draw labelled diagram of frog egg.

14. Draw labelled diagram of chick egg.

15. Define allele frequency and genotype frequency.

Allele Frequency: Allele frequency is the proportion of a specific allele of a gene in a population. It is calculated by dividing the number of copies of the allele by the total number of alleles for that gene in the population.

Genotype Frequency: Genotype frequency is the proportion of individuals in a population that carry a specific genotype. It is calculated by dividing the number of individuals with that genotype by the total number of individuals in the population.

16. What is organogenesis?

Organogenesis: Organogenesis is the process by which the organs and tissues of an organism develop from the embryonic germ layers. It occurs during the embryonic development phase and involves the differentiation of cells and the formation of complex structures.

17. What are fate maps?

Fate Maps: Fate maps are diagrams that trace the developmental fate of cells in an embryo. They show which parts of the early embryo will develop into specific tissues and organs in the adult organism, based on cell lineage and positional information.

18. Short notes on biological species concept.

Biological Species Concept: The biological species concept defines a species as a group of interbreeding natural populations that are reproductively isolated from other such groups. According to this concept, species are groups of organisms that can exchange genes and produce fertile offspring. Reproductive isolation can occur due to various prezygotic and postzygotic barriers, preventing gene flow between different species. This concept emphasizes the importance of reproductive isolation in maintaining species boundaries and has been widely used in evolutionary biology, though it has limitations, particularly for asexual organisms and fossil species.

19. List causes of extinction.

Habitat Destruction: Loss of habitat due to deforestation, urbanization, and agriculture.
Climate Change: Rapid changes in climate that affect species' survival.
Pollution: Contamination of air, water, and soil affecting health and reproduction.
Overexploitation: Excessive hunting, fishing, and harvesting of species.
Invasive Species: Non-native species that outcompete or prey on native species.
Disease: Spread of new or existing diseases that can decimate populations.
Natural Disasters: Events like volcanic eruptions, earthquakes, and tsunamis.

20. Define evolution. Who coined the term evolution?

Evolution: Evolution is the process by which species of organisms change over time through mechanisms such as natural selection, mutation, gene flow, and genetic drift. These changes can lead to the development of new species and the adaptation of populations to their environments.

The term "evolution" in the context of biological change was popularized by Charles Darwin in the 19th century, although the concept of evolutionary change was discussed by earlier scientists like Jean-Baptiste Lamarck.

ENVIRONMENTAL BIOLOGY, WILDLIFE MANAGEMENT AND CONSERVATION

1. What are trophic levels? List them.

Trophic levels refer to the hierarchical levels in an ecosystem, where organisms are grouped based on their feeding position along the food chain. Each level represents a step in the flow of energy and nutrients from primary producers to apex predators.

The main trophic levels are:

Primary Producers (Trophic Level 1): These are autotrophs, primarily plants and algae, that produce their own food through photosynthesis.
Primary Consumers (Trophic Level 2): Herbivores that feed on primary producers.
Secondary Consumers (Trophic Level 3): Carnivores and omnivores that feed on primary consumers.
Tertiary Consumers (Trophic Level 4): Predators that feed on secondary consumers.
Quaternary Consumers (Trophic Level 5): Apex predators at the top of the food chain that have no natural predators.

2. What are pollutants? Give examples.

Pollutants are substances that cause pollution by contaminating the natural environment, leading to adverse effects on living organisms and ecosystems. They can be chemical, physical, or biological agents.

Examples of pollutants:

Chemical Pollutants: Heavy metals (e.g., lead, mercury), pesticides (e.g., DDT), industrial chemicals (e.g., PCBs).
Physical Pollutants: Plastic waste, particulate matter (PM2.5 and PM10), radioactive materials.
Biological Pollutants: Pathogens like bacteria, viruses, invasive species.

3. Distinguish food chain and food web.

Food Chain: A linear sequence of organisms where each is eaten by the next member in the chain. It typically shows a single path of energy flow in an ecosystem. Example: Grass → Grasshopper → Frog → Snake → Eagle.
Food Web: A complex network of interconnected food chains within an ecosystem, illustrating how different chains overlap and interact. It shows multiple paths of energy flow and more accurately represents ecosystem interactions. Example: In a forest, a food web might show that an eagle can eat snakes, frogs, and small mammals.

4. Define ecology. Who coined the term?

Ecology is the branch of biology that studies the interactions between organisms and their environment, including both biotic (living) and abiotic (non-living) components.

The term "ecology" was coined by the German biologist Ernst Haeckel in 1866.

5. Define the term population density.

Population density refers to the number of individuals of a particular species per unit area or volume of habitat. It is a measure used in ecology to describe how crowded a population is within a given space.

6. Name two biosphere reserves of India.

Nilgiri Biosphere Reserve: Located in the Western Ghats, covering parts of Tamil Nadu, Kerala, and Karnataka.
Sundarbans Biosphere Reserve: Located in the delta region of the Padma, Meghna, and Brahmaputra river basins in West Bengal.

7. Expand CITES and TRAFFIC.

CITES: Convention on International Trade in Endangered Species of Wild Fauna and Flora.
TRAFFIC: The Wildlife Trade Monitoring Network.

8. Expand HIPPO.

HIPPO is an acronym used to summarize the primary threats to biodiversity:

Habitat Destruction
Invasive Species
Pollution
Population (human overpopulation)
Overharvesting

9. What is home range and territory?

Home Range: The area in which an animal lives and moves on a periodic basis. It includes all the resources the animal needs to survive and reproduce but is not defended against others of the same species.
Territory: A specific area that an animal actively defends against intruders of the same species. It is usually smaller than the home range and is essential for activities like mating, feeding, and nesting.

10. Name two national parks and wildlife sanctuaries of India.

National Parks:
1. Jim Corbett National Park: Located in Uttarakhand, it is the oldest national park in India.
2. Kaziranga National Park: Located in Assam, known for its population of the Indian one-horned rhinoceros.
Wildlife Sanctuaries:
1. Bharatpur Bird Sanctuary (Keoladeo National Park): Located in Rajasthan, famous for avian fauna.
2. Periyar Wildlife Sanctuary: Located in Kerala, known for its elephants and tigers.

11. Define natality and mortality.

Natality: The rate at which new individuals are added to a population through reproduction (birth rate).
Mortality: The rate at which individuals are lost from a population due to death (death rate).

12. Define biomagnification. List its causes.

Biomagnification: The process by which the concentration of toxic substances increases in each successive link of the food chain. These substances are usually persistent organic pollutants that do not easily degrade in the environment.

Causes:

Use of pesticides and herbicides (e.g., DDT).
Industrial discharge of pollutants (e.g., PCBs, mercury).
Improper disposal of waste, leading to contaminants entering the food chain.

13. Define bioaccumulation. List the effects.

Bioaccumulation: The process by which organisms accumulate toxic substances faster than they can eliminate them, leading to a build-up of these substances in their bodies over time.

Effects:

Reduced reproductive success and growth in organisms.
Neurological and physiological damage.
Increased susceptibility to disease.
Transfer of toxins to predators, including humans, through the food chain.

14. Define bioremediation. List the controlling measures.

Bioremediation: The use of microorganisms, fungi, plants, or their enzymes to detoxify and remove pollutants from the environment, thereby restoring contaminated sites.

Controlling Measures:

Selection of appropriate microorganisms or plants for specific contaminants.
Monitoring and managing environmental conditions (e.g., temperature, pH, nutrients) to enhance bioremediation efficiency.
Containment and stabilization of contaminants to prevent further spread.
Regular assessment and adjustment of bioremediation strategies based on site-specific conditions and progress.

15. Short notes on animal census.

Animal Census: A systematic process of counting and recording animal populations within a specified area and time frame. It helps in understanding population dynamics, assessing the status of species, and informing conservation efforts.

Key Aspects:

Methods: Direct observation, camera trapping, aerial surveys, mark-recapture techniques.
Importance: Provides data on population size, density, distribution, and trends. Helps in identifying endangered species and planning conservation strategies.
Challenges: Requires significant resources, trained personnel, and can be affected by environmental factors and animal behavior.

16. Short notes on red data book.

Red Data Book: A document that lists endangered and threatened species of animals, plants, and fungi, along with their conservation status. It serves as a comprehensive record of the risk of extinction faced by various species.