Botany
- You are given a tissue with its potential for differentiation in an artificial culture. Which of the following pairs of hormones would you add to the medium to secure shoots as well as roots? Answer: 1. Auxin and cytokinin In tissue culture, the ratio of auxin to cytokinin controls differentiation. A balanced supply gives both roo... 1
- Phytochrome is a Answer: 3. chromoprotein Phytochrome is a pigment protein with a light-absorbing non-protein part (a linear tetrapyrrole, phytochromobilin)... 1
- Which one of the following statements is not correct? Answer: 2. In potato, banana and ginger, the plantlets arise from the internodes present in the modified stem. In potato, banana and ginger... 1
- Which one of the following generates new genetic combinations leading to variation? Answer: 2. Sexual reproduction Sexual reproduction involves meiosis (crossing over, independent assortment) and fusion of gametes from two p... 1
- In majority of angiosperms Answer: 2. reduction division occurs in the megaspore mother cells In most angiosperms the megaspore mother cell (2n) divides by meiosis (re... 1
- The ovule of an angiosperm is technically equivalent to Answer: 4. megasporangium The ovule is the structure in which the megaspore mother cell and then the embryo sac form. It is therefore equiva... 1
- Pollination in water hyacinth and water lily is brought about by the agency of Answer: 1. insects or wind Water hyacinth and water lily are aquatic plants, but their flowers rise above the water and are pollinated by in... 1
- Match Column—I with Column—II and select the correct option using the codes given below :Column—I: a. Pistils fused together; b. Formation of gametes; c. Hyphae of higher Ascomycetes; d. Unisexual female flowerColumn—II: (i) Gametogenesis; (ii) Pisti… Answer: 3. (iii) (i) (iv) (ii) Match each term by its meaning: a. Pistils fused together = syncarpous (iii) b. Formation of gametes = gameto... 1
- A non-proteinaceous enzyme is Answer: 1. ribozyme Almost all enzymes are proteins, but a few RNA molecules also act as catalysts. Ribozyme is a catalytic RNA (for example... 1
- Select the mismatch. Answer: 1. Large central vacuoles—Animal cells Large central vacuoles are a feature of mature plant cells, not animal cells. Animal cells ha... 1
- Select the wrong statement. Answer: 1. Pili and fimbriae are mainly involved in motility of bacterial cells. Pili and fimbriae are surface structures used for attachmen... 1
- Which of the following is wrongly matched in the given table ?Microbe | Product | Application(1) Trichoderma polysporum | Cyclosporin A | immunosuppressive drug(2) Monascus purpureus | Statins | lowering of blood cholesterol(3) Streptococcus | Strept… Answer: 4. Clostridium butylicum - Lipase - removal of oil stains Clostridium butylicum is used to produce butyric acid. Lipase is obtained... 1
- The primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals, include the : Answer: 3. Methanogens Methanogens are archaebacteria found in the rumen of cattle. They produce methane and are responsible for biogas prod... 1
- A typical fat molecule is made up of : Answer: 2. One glycerol and three fatty acid molecules A triglyceride (typical fat) is formed by esterification of one glycerol with three f... 1
- Which of the following is not a characteristic feature during mitosis in somatic cells ? Answer: 4. Synapsis Synapsis (pairing of homologous chromosomes) occurs in prophase I (zygotene) of meiosis, not in mitosis. Spindle fibres,... 1
- A cell at telophase stage is observed by a student in a plant brought from the field. He tells his teacher that this cell is not like other cells at telophase stage. There is no formation of cell plate and thus the cell is containing more number of c… Answer: 2. Polyploidy Failure of cell plate formation in telophase (cytokinesis fails) leaves a cell with a doubled chromosome number. Cells... 1
- Chrysophytes, Euglenoids, Dinoflagellates and Slime moulds are included in the kingdom : Answer: 2. Protista Chrysophytes (diatoms), euglenoids, dinoflagellates, slime moulds and protozoans are unicellular eukaryotes placed in Ki... 1
- Depletion of which gas in the atmosphere can lead to an increased incidence of skin cancers : Answer: 2. Ozone The ozone layer absorbs harmful UV-B radiation. When ozone is depleted, more UV reaches the earth and causes skin cancers a... 1
- A river with an inflow of domestic sewage rich in organic waste may result in : Answer: 4. Death of fish due to lack of oxygen. Sewage rich in organic waste is decomposed by microbes, which use up dissolved oxygen (high... 1
- In a testcross involving F_1 dihybrid flies, more parental-type offspring were produced than the recombinant-type offspring. This indicates : Answer: 3. The two genes are linked and present on the same chromosome. In a testcross with an F₁ dihybrid, independent assortment gives 1:1... 1
- Water vapour comes out from the plant leaf through the stomatal opening. Through the same stomatal opening carbon dioxide diffuses into the plant during photosynthesis. Reason out the above statements using one of following options : Answer: 2. Both processes can happen together because the diffusion coefficient of water and CO ₂ is different. Both processes can occur tog... 1
- Seed formation without fertilization in flowering plants involves the process of : Answer: 4. Apomixis Formation of seeds without fertilisation is called apomixis, in which the embryo develops from diploid cells of the ovul... 1
- Which of the following statements is not correct ? Answer: 1. Pollen grains of many species can germinate on the stigma of a flower, but only one pollen tube of the same species grows into th... 1
- Cotyledon of maize grain is called : Answer: 4. scutellum In maize (a monocot) the single cotyledon is a shield-shaped structure called the scutellum, lying towards one side of... 1