BITSAT Biology (Optional, In Lieu Of Mathematics) Flashcards

24 sample cards from the Biology (Optional, In Lieu Of Mathematics) deck

Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.

1. Trace the path of air during human respiration from the nostrils to the gas-exchange site.

   Nostrils → nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli (site of gas exchange).

2. How is most carbon dioxide transported in human blood?

   About 70% as bicarbonate ions (HCO3-), around 20-23% bound to hemoglobin as carbaminohemoglobin, and about 7% dissolved in plasma.

3. What are the four chambers of the human heart and the valves between atria and ventricles?

   Two atria and two ventricles. The tricuspid valve lies between the right atrium and right ventricle; the bicuspid (mitral) valve between the left atrium and left ventricle.

4. What is the functional unit of the kidney and what are its main parts?

   The nephron. Its main parts are the Bowman's capsule (with glomerulus), proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct.

5. Distinguish between the central and peripheral nervous systems.

   The central nervous system (CNS) consists of the brain and spinal cord; the peripheral nervous system (PNS) consists of the nerves connecting the CNS to the rest of the body.

6. Name the three major regions of the human brain and one function of each.

   Forebrain (cerebrum - thinking/memory), Midbrain (relay of visual/auditory reflexes), and Hindbrain (cerebellum - balance; medulla - involuntary actions like breathing).

7. What is the difference between endocrine and exocrine glands?

   Endocrine glands are ductless and secrete hormones directly into the blood; exocrine glands secrete their products through ducts (e.g., salivary, sweat glands).

8. What are the two main proteins in muscle contraction and what is the sliding filament theory?

   Actin (thin filament) and myosin (thick filament). The sliding filament theory states muscle contracts when actin filaments slide over myosin, shortening the sarcomere.

9. How many bones are in the adult human body, and how is the skeleton divided?

   206 bones, divided into the axial skeleton (skull, vertebral column, ribs, sternum) and the appendicular skeleton (limbs and girdles).

10. Differentiate between asexual and sexual reproduction.

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

11. What is the difference between oviparous and viviparous animals?

    Oviparous animals lay eggs that develop and hatch outside the body (e.g., birds); viviparous animals give birth to live young that develop inside the mother (e.g., mammals).

12. What is the full form of IVF and STD in the context of reproductive health?

    IVF = In Vitro Fertilisation; STD = Sexually Transmitted Disease (e.g., AIDS, syphilis, gonorrhoea).

13. Name three commonly used methods of contraception across different categories.

    Barrier methods (condoms), Intrauterine devices (IUDs/Copper-T), and Hormonal methods (oral contraceptive pills).

14. State Mendel's three laws of inheritance.

    Law of Dominance, Law of Segregation (alleles separate during gamete formation), and Law of Independent Assortment (genes for different traits assort independently).

15. What phenotypic ratio is obtained in the F2 generation of a Mendelian dihybrid cross?

    9:3:3:1 (showing independent assortment of two pairs of contrasting traits).

16. What experiment established DNA as the genetic material, and what are the base-pairing rules in DNA?

    The Hershey-Chase experiment (using bacteriophages) confirmed DNA as the genetic material. Base pairing: Adenine pairs with Thymine (A-T), Guanine pairs with Cytosine (G-C).

17. What is the central dogma of molecular biology?

    The flow of genetic information: DNA → RNA → Protein, via transcription (DNA to RNA) and translation (RNA to protein), proposed by Francis Crick.

18. What is biofortification and name two diseases caused by pathogens that affect human welfare?

    Biofortification is breeding crops with higher nutritional value (vitamins, minerals, proteins). Examples of pathogenic diseases: malaria (Plasmodium) and typhoid (Salmonella typhi).

19. What are restriction enzymes (molecular scissors) used for in biotechnology?

    Restriction endonucleases cut DNA at specific recognition sequences, producing fragments with sticky ends used to make recombinant DNA. PCR amplifies DNA, and DNA ligase joins fragments.

20. Define an ecosystem and distinguish between a food chain and a food web.

    An ecosystem is a community of organisms interacting with their physical environment. A food chain is a single linear sequence of who-eats-whom; a food web is an interconnected network of many food chains.

21. State the 10 percent law of energy transfer in an ecosystem (Lindeman).

    Only about 10% of the energy at one trophic level is transferred to the next higher trophic level; the rest is lost mainly as heat in metabolism.

22. What is the difference between in-situ and ex-situ conservation of biodiversity?

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

23. What evidence did Darwin's theory of evolution by natural selection rely on, and what is its core idea?

    Core idea: organisms with favourable heritable variations survive and reproduce more (survival of the fittest), gradually changing populations. Evidence includes fossils, homologous/analogous organs, and embryology.

24. Distinguish between homologous and analogous organs with examples.

    Homologous organs have similar structure/origin but different functions (forelimbs of humans, whales, bats - divergent evolution); analogous organs have different structure/origin but similar function (wings of birds and insects - convergent evolution).

What this deck covers

Biology (Optional, In Lieu Of Mathematics) flashcards FAQ