VITEEE Biology (Alternative to Mathematics) Syllabus

What is pleiotropy?

A condition where a single gene affects multiple, seemingly unrelated phenotypic traits (e.g., the gene for sickle-cell anaemia affecting blood, spleen, and other organs).

State Darwin's theory of natural selection in one sentence.

Individuals with heritable variations better suited to their environment survive and reproduce more successfully, so favourable traits accumulate in the population over generations (survival of the fittest).

What is the Hardy-Weinberg principle, and give the allele/genotype frequency equations.

It states allele and genotype frequencies stay constant in a population not subject to evolutionary forces. Equations: p + q = 1 and p² + 2pq + q² = 1, where p and q are allele frequencies.

List the five factors that disturb Hardy-Weinberg equilibrium.

Gene migration (gene flow), genetic drift, mutation, genetic recombination, and natural selection.

What is the difference between homologous and analogous organs? Give one example each.

Homologous organs have common ancestry but different functions (e.g., forelimbs of human, whale, bat — divergent evolution). Analogous organs have different origins but similar functions (e.g., wings of insect and bird — convergent evolution).

Define mutation and distinguish point mutation from frameshift mutation.

A mutation is a heritable change in DNA sequence. A point mutation changes a single base pair (substitution); a frameshift mutation results from insertion or deletion of bases (not in multiples of three), shifting the entire reading frame.

What molecular change causes sickle-cell anaemia?

A point mutation (substitution) in the β-globin gene causes glutamic acid to be replaced by valine at position 6 of the β-chain of haemoglobin (GAG → GTG).

What is the difference between aneuploidy and polyploidy?

Aneuploidy is the gain or loss of one or a few chromosomes (e.g., trisomy 21); polyploidy is the presence of one or more complete extra sets of chromosomes (e.g., triploid, tetraploid).

Write the overall balanced equation for photosynthesis.

6CO₂ + 12H₂O → (light, chlorophyll) C₆H₁₂O₆ + 6O₂ + 6H₂O.

Where do the light reactions and the Calvin cycle of photosynthesis occur?

Light reactions occur in the thylakoid membranes of the chloroplast; the Calvin cycle (dark reaction) occurs in the stroma.

What is transpiration, and name the structures mainly responsible for it?

Transpiration is the loss of water vapour from aerial plant parts, mainly through stomata (also lenticels and cuticle). Stomata, bordered by guard cells, are the chief sites.

Name three major plant hormones and one function of each.

Auxin — promotes cell elongation and apical dominance; Gibberellin — stimulates stem elongation and seed germination; Cytokinin — promotes cell division; (also Abscisic acid — stress/dormancy; Ethylene — fruit ripening).

Distinguish between C3 and C4 plants by their first stable product.

C3 plants form a 3-carbon compound (3-phosphoglyceric acid, PGA) first; C4 plants form a 4-carbon compound (oxaloacetic acid, OAA) first and are more efficient under high temperature/light.

Trace the path of blood through the four chambers of the human heart.

Deoxygenated blood enters the right atrium → right ventricle → pulmonary artery to lungs → oxygenated blood returns via pulmonary veins to left atrium → left ventricle → aorta to body.

What are the functional unit of the kidney and its primary function?

The nephron is the functional unit of the kidney; it filters blood and forms urine through filtration, reabsorption, and secretion.

Name the enzyme in saliva and the substrate it acts on.

Salivary amylase (ptyalin) acts on starch, breaking it down into maltose.

What is the role of haemoglobin and where is most CO₂ transported?

Haemoglobin in red blood cells transports oxygen (as oxyhaemoglobin) and some CO₂. Most CO₂ (about 70%) is transported in plasma as bicarbonate ions (HCO₃⁻).

What gas exchange surface is used in human lungs and what is its functional unit?

The alveoli are the functional units; their thin, moist, highly vascular walls allow O₂ and CO₂ exchange by diffusion.

What are the components of blood and the approximate composition?

Blood is plasma (about 55%) and formed elements (about 45%): red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes).

Define homeostasis and name the hormone pair regulating blood glucose.

Homeostasis is the maintenance of a stable internal environment. Insulin (lowers blood glucose) and glucagon (raises blood glucose), both from the pancreas, regulate blood glucose.

What is the lymphatic system's role in body fluids?

It collects excess interstitial (tissue) fluid as lymph and returns it to the blood, absorbs fats from the intestine, and houses immune cells to fight infection.

Distinguish between asexual and sexual reproduction.

Asexual reproduction involves a single parent, no gamete fusion, and produces genetically identical offspring (clones); sexual reproduction involves two parents, fusion of gametes, and produces genetically variable offspring.

What is double fertilization in angiosperms?

One male gamete fuses with the egg to form the diploid zygote (syngamy); the second male gamete fuses with two polar nuclei to form the triploid (3n) primary endosperm nucleus (triple fusion).

Name the gonadotropins from the pituitary and their roles in human reproduction.

FSH (follicle-stimulating hormone) stimulates follicle/sperm development; LH (luteinizing hormone) triggers ovulation and corpus luteum formation (and testosterone secretion in males).

What pathogen causes malaria and which vector transmits it?

Malaria is caused by the protozoan Plasmodium (e.g., P. vivax, P. falciparum) and is transmitted by the bite of the female Anopheles mosquito.

Distinguish between active and passive immunity.

Active immunity develops when the body's own immune system produces antibodies after exposure to an antigen (infection or vaccine) and is long-lasting; passive immunity is the transfer of ready-made antibodies (e.g., mother to fetus, antiserum) and is short-lived.

What are the goals and one technique of plant breeding for crop improvement?

To develop crops with higher yield, disease resistance, and better nutrition. A key technique is hybridization — crossing genetically different plants to combine desirable traits, often followed by selection.

What two enzymes are essential tools in recombinant DNA technology, and what does each do?

Restriction endonucleases cut DNA at specific recognition sequences producing fragments (often with sticky ends); DNA ligase joins DNA fragments together.

What is a cloning vector and name a commonly used one?

A cloning vector is a DNA molecule (e.g., plasmid such as pBR322) that carries foreign DNA into a host cell and replicates it; it must have an origin of replication, selectable markers, and restriction sites.

What is PCR and what are its three main steps?

PCR (Polymerase Chain Reaction) amplifies a specific DNA segment in vitro using Taq polymerase. Steps: denaturation (strand separation by heat), annealing (primers bind), and extension (DNA polymerase synthesizes new strands).

Name one major application of biotechnology in agriculture and one in medicine.

Agriculture: Bt cotton — a transgenic crop carrying a Bacillus thuringiensis gene for insect (pest) resistance. Medicine: production of human recombinant insulin (Humulin) using genetically engineered bacteria.

In an ecosystem, distinguish between a food chain and a food web, and define a trophic level.

A food chain is a linear sequence of who eats whom (producer → herbivore → carnivore); a food web is interconnected food chains. A trophic level is each feeding step in the chain through which energy passes.

State the 10% law (Lindeman's law) of energy flow in an ecosystem.

Only about 10% of the energy at one trophic level is transferred to and stored in the next higher trophic level; the rest is lost mainly as heat (metabolism), limiting food chain length.

What is biodiversity and what are its three hierarchical levels?

Biodiversity is the variety and variability of life. Its three levels are genetic diversity (within a species), species diversity (number of species in a region), and ecological/ecosystem diversity (variety of habitats and ecosystems).

Distinguish between in-situ and ex-situ conservation with one example each.

In-situ conservation protects species in their natural habitat (e.g., national parks, biosphere reserves, sanctuaries); ex-situ conservation protects species outside their habitat (e.g., zoos, botanical gardens, seed banks).

What gases are chiefly responsible for the greenhouse effect and global warming?

Carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), water vapour, and chlorofluorocarbons (CFCs); CO₂ is the largest contributor.

What causes ozone layer depletion and what is its main harmful consequence?

Chlorofluorocarbons (CFCs) release chlorine that breaks down stratospheric ozone (O₃). Depletion increases harmful UV-B radiation reaching Earth, raising risks of skin cancer, cataracts, and damage to ecosystems.

What is biomagnification (biological magnification)?

The progressive increase in concentration of a non-degradable toxic substance (e.g., DDT, mercury) at successive trophic levels of a food chain, becoming highest in top consumers.

What is BOD and what does a high BOD value indicate about water?

BOD (Biochemical Oxygen Demand) is the amount of dissolved oxygen needed by microorganisms to decompose organic matter in water. A high BOD indicates heavy organic pollution and poor water quality.