KCET Biology - Zoology Syllabus

Define vital capacity of the lungs.

The maximum volume of air a person can breathe out after a maximum inspiration; Vital Capacity = ERV + TV + IRV (Expiratory Reserve + Tidal + Inspiratory Reserve Volume).

Give the formula for Tidal Volume-based pulmonary ventilation and a typical TV value.

Pulmonary ventilation = Tidal Volume x respiratory rate (breaths/min); typical TV is about 500 mL (about 6000-8000 mL/min total).

How is oxygen mainly transported in the blood?

About 97% of O2 is transported bound to haemoglobin as oxyhaemoglobin (HbO2); about 3% is dissolved in plasma. Each haemoglobin can bind four O2 molecules.

How is carbon dioxide transported in blood?

About 70% as bicarbonate ions (HCO3-), about 20-25% bound to haemoglobin as carbaminohaemoglobin, and about 7% dissolved in plasma; the enzyme carbonic anhydrase is key.

What is the chloride shift (Hamburger's phenomenon)?

As HCO3- diffuses out of RBCs into plasma, Cl- ions move into the RBCs to maintain ionic/electrical balance during CO2 transport.

Describe the double circulation pathway of the human heart.

Pulmonary circulation: right ventricle to lungs (deoxygenated) and back to left atrium (oxygenated); systemic circulation: left ventricle to body and back to right atrium. Blood passes through the heart twice per full cycle.

What is the pacemaker of the heart and the normal order of impulse conduction?

The SA (sinoatrial) node is the pacemaker; impulse: SA node to AV node to bundle of His to right and left bundle branches to Purkinje fibres.

What does the P wave, QRS complex, and T wave of an ECG represent?

P wave = atrial depolarisation; QRS complex = ventricular depolarisation (and atrial repolarisation is masked); T wave = ventricular repolarisation.

What is the composition and function of lymph?

Lymph is a colourless fluid (plasma minus most proteins and RBCs, containing WBCs/lymphocytes); it returns interstitial fluid to blood, absorbs fats from intestine (via lacteals), and is part of immunity.

Name the structural and functional unit of the kidney and its main parts.

The nephron; parts: Bowman's capsule with glomerulus (Malpighian/renal corpuscle), proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct.

What are the three main processes of urine formation?

Glomerular filtration (ultrafiltration at Bowman's capsule), tubular reabsorption (selective reabsorption of useful substances), and tubular secretion (active secretion of wastes like H+, K+, NH3).

What is the role of ADH and the counter-current mechanism in concentrating urine?

ADH (vasopressin) increases water reabsorption in the DCT/collecting duct; the counter-current mechanism in the loop of Henle and vasa recta maintains the medullary osmotic gradient enabling concentrated urine.

Classify animals by their nitrogenous waste: ammonotelic, ureotelic, uricotelic.

Ammonotelic excrete ammonia (most aquatic animals, bony fish); ureotelic excrete urea (mammals, amphibians, marine fish); uricotelic excrete uric acid (reptiles, birds, insects, land snails).

Describe the sliding filament theory of muscle contraction.

Contraction occurs when actin (thin) filaments slide over myosin (thick) filaments; myosin heads form cross-bridges with actin, pulling them toward the centre of the sarcomere, shortening it (H-zone and I-band shrink, A-band constant). Requires Ca2+ and ATP.

What is the role of calcium ions in muscle contraction?

Ca2+ released from the sarcoplasmic reticulum binds troponin, shifting tropomyosin to expose actin's myosin-binding sites, allowing cross-bridge formation and contraction.

How many bones are in the human skeleton and what are its two divisions?

206 bones; axial skeleton (80 bones: skull, vertebral column, ribs, sternum) and appendicular skeleton (126 bones: limbs and girdles).

Name the three types of joints based on movement with an example of each.

Fibrous/fixed (immovable, e.g. skull sutures), cartilaginous (slightly movable, e.g. between vertebrae), and synovial (freely movable, e.g. ball-and-socket of shoulder, hinge of knee).

Describe the structure of a typical neuron.

A neuron has a cell body (cyton/soma with nucleus and Nissl granules), dendrites (receive impulses), and an axon (transmits impulses); axons may be myelinated with nodes of Ranvier for saltatory conduction.

What is the resting membrane potential and how is it maintained?

About -70 mV; maintained by the Na+/K+ pump (3 Na+ out, 2 K+ in) and selective permeability, keeping the inside negative relative to the outside (high K+ inside, high Na+ outside).

Outline how a nerve impulse is transmitted across a chemical synapse.

Action potential reaches the axon terminal, Ca2+ enters, synaptic vesicles release neurotransmitter (e.g. acetylcholine) into the synaptic cleft, which binds receptors on the postsynaptic membrane, generating a new impulse.

Name the parts of the human brain and one function of each major part.

Forebrain (cerebrum - thinking/memory; thalamus - relay; hypothalamus - homeostasis), midbrain (reflexes for sight/hearing), hindbrain (cerebellum - balance/coordination; pons; medulla - controls heartbeat, breathing).

Match these hormones to their endocrine glands: insulin, thyroxine, adrenaline, ADH.

Insulin - pancreas (beta cells of islets of Langerhans); thyroxine - thyroid gland; adrenaline - adrenal medulla; ADH - secreted by hypothalamus, released from posterior pituitary.

What are the actions of insulin and glucagon in blood glucose regulation?

Insulin lowers blood glucose (promotes glycogenesis and cellular glucose uptake); glucagon raises blood glucose (promotes glycogenolysis and gluconeogenesis). They are antagonistic.

Which hormone is called the emergency / fight-or-flight hormone and what does it do?

Adrenaline (epinephrine) from the adrenal medulla; it increases heart rate, blood pressure, breathing rate, blood glucose, and alertness during stress.

Name the hormones secreted by the anterior pituitary.

GH (growth hormone), TSH, ACTH, FSH, LH, prolactin (PRL), and MSH. (Posterior pituitary stores/releases oxytocin and ADH made by the hypothalamus.)

What is spermatogenesis and where does it occur?

The formation of haploid sperm from diploid spermatogonia by meiosis, occurring in the seminiferous tubules of the testes; stimulated by FSH and testosterone, supported by Sertoli cells.

Describe the menstrual cycle phases and the dominant hormones.

Menstrual phase (shedding of endometrium), follicular/proliferative phase (FSH, rising estrogen, follicle growth), ovulatory phase (LH surge causes ovulation ~day 14), and luteal/secretory phase (corpus luteum secretes progesterone).

What is the role of the placenta in human pregnancy?

It connects the foetus to the uterine wall for exchange of nutrients, gases (O2/CO2) and wastes, and acts as an endocrine organ secreting hCG, progesterone, estrogen, and human placental lactogen.

List two barrier and two hormonal/IUD contraceptive methods.

Barrier: condoms and diaphragms/cervical caps; Hormonal: oral contraceptive pills (e.g. Saheli) and injectables/implants; IUDs include Copper-T (Cu-releasing) and hormone-releasing (LNG-20).

What is amniocentesis and why is its misuse legally banned in India?

A prenatal test analysing amniotic fluid to detect foetal genetic/chromosomal disorders; it is banned for sex determination because of its misuse for female foeticide.

What is the chromosomal basis of sex determination in humans?

Humans have XX (female) and XY (male); the male is heterogametic (produces X or Y sperm) and determines the sex of the offspring; females are homogametic (XX).

Explain the inheritance pattern and cause of haemophilia.

Haemophilia is an X-linked recessive disorder where blood fails to clot due to deficiency of a clotting factor; it is more common in males (XY) since one recessive allele is enough to express it.

What causes sickle-cell anaemia at the molecular level?

An autosomal recessive point mutation (GAG to GTG) replacing glutamic acid with valine at the 6th position of the beta-globin chain of haemoglobin (HbS), causing RBCs to become sickle-shaped under low O2.

Name the chromosomal abnormality and karyotype of Down's syndrome.

Trisomy of chromosome 21 (47 chromosomes); caused by failure of chromosomes to separate (non-disjunction).

Contrast Darwin's natural selection with Lamarck's theory of evolution.

Lamarck proposed inheritance of acquired characters (use and disuse); Darwin proposed natural selection - variation exists, and individuals best adapted to the environment survive and reproduce ('survival of the fittest').

What is the Hardy-Weinberg principle and its equation?

In a population at equilibrium, allele frequencies remain constant across generations (no evolution) when there is no mutation, migration, selection, genetic drift, or random mating. Equation: p^2 + 2pq + q^2 = 1, where p + q = 1.

Differentiate homologous and analogous organs with examples.

Homologous organs have similar structure/origin but different functions (divergent evolution, e.g. forelimbs of whale, bat, human); analogous organs have different structure/origin but similar function (convergent evolution, e.g. wings of insect and bird).

Distinguish active and passive immunity.

Active immunity is produced by the host's own body in response to antigens/vaccines (slow but long-lasting); passive immunity is ready-made antibodies given from outside (e.g. mother's milk, antivenom; fast but short-lived).

Name the causative organisms of malaria, typhoid, and amoebiasis.

Malaria - Plasmodium (e.g. P. vivax, P. falciparum); typhoid - Salmonella typhi; amoebiasis (amoebic dysentery) - Entamoeba histolytica.

What are the two types of lymphocytes and their roles in immunity?

B-lymphocytes produce antibodies (humoral/antibody-mediated immunity); T-lymphocytes mediate cell-mediated immunity (CMI) and help/regulate B cells (e.g. helper T, cytotoxic T cells).

How does HIV cause AIDS at the cellular level?

HIV (a retrovirus) infects and destroys helper T-lymphocytes (CD4+ cells); their depletion cripples the immune system, leaving the body vulnerable to opportunistic infections.

Which microbes are used to produce curd and to make bread/wine respectively?

Lactic Acid Bacteria (LAB, e.g. Lactobacillus) curdle milk into curd; Saccharomyces cerevisiae (baker's/brewer's yeast) is used for bread (CO2) and for alcohol/wine fermentation.

Name the microbial sources of penicillin, citric acid, and cyclosporin A.

Penicillin - fungus Penicillium notatum/chrysogenum; citric acid - Aspergillus niger; cyclosporin A (immunosuppressant) - fungus Trichoderma polysporum.

What are biogas, its main component, and the microbes responsible?

Biogas is a mixture of gases (mainly methane, CH4) produced by anaerobic microbial digestion of organic waste; methanogens such as Methanobacterium (found in cattle dung/gobar) produce it.

Give examples of biofertilizers and biocontrol agents.

Biofertilizers: Rhizobium, Azospirillum, Azotobacter, cyanobacteria (e.g. Anabaena), mycorrhiza (Glomus). Biocontrol agents: Bacillus thuringiensis (Bt), Trichoderma, Baculoviruses (NPV), and ladybird/dragonfly.

What are the three key steps/tools of genetic engineering (recombinant DNA technology)?

(1) Identifying and cutting DNA with restriction enzymes, (2) inserting the gene into a vector to form recombinant DNA, and (3) transferring it into a host and amplifying/expressing it (cloning).

What is the function of restriction endonucleases and what are 'sticky ends'?

Restriction endonucleases (molecular scissors) cut DNA at specific palindromic recognition sequences; staggered cuts leave single-stranded overhangs called sticky ends that base-pair with complementary ends to join DNA fragments.

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

A cloning vector is a DNA molecule (e.g. plasmid pBR322, bacteriophages, Ti plasmid of Agrobacterium) that carries the foreign gene into a host cell; it has an origin of replication (ori), selectable markers, and recognition sites.

What is PCR and what are its three steps?

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