NEET UG
- Identify the correct statement on 'inhibin' : Answer: 2. Is produced by granulose cells in ovary and inhibits the secretion of FSH. Key idea: Inhibin is made by the granulosa cells of th... 1
- The amino acid Tryptophan is the precursor for the synthesis of : Answer: 1. Melatonin and Serotonin Tryptophan is the precursor of melatonin and serotonin. Thyroid hormones (thyroxine, T₃) are made from ty... 1
- Lack of relaxation between successive stimuli in sustained muscle contraction is known as : Answer: 3. Tetanus Sustained contraction caused by rapid successive stimuli, with no time to relax between them, is tetanus. Spasm: sudden i... 1
- Which type of tissue correctly matches with its location ?Tissue | Location(1) Smooth muscle | Wall of intestine(2) Areolar tissue | Tendons(3) Transitional epithelium | Tip of nose(4) Cuboidal epithelium | Lining of stomach Answer: 1. Smooth muscle - Wall of intestine Smooth (visceral) muscle forms the walls of hollow organs such as the intestine. 2: Areolar tis... 1
- Spindle fibres attach on to : Answer: 2. Kinetochore of the chromosome Key idea: Spindle fibres attach to the kinetochore. The kinetochore is a disc-shaped protein struct... 1
- In meiosis crossing over is initiated at : Answer: 1. Pachytene Key idea: Crossing over takes place at pachytene. At pachytene (prophase I), recombination nodules form and the enzyme... 1
- Microtubules are the constituents of : Answer: 2. Spindle fibres, Centrioles and Cilia Key idea: Microtubules make up spindle fibres, centrioles (and basal bodies), and the axonem... 1
- One of the major components of cell wall of most fungi is : Answer: 1. Chitin Key idea: The fungal cell wall is made mostly of chitin (a polymer of N-acetylglucosamine) and polysaccharides. Peptidogly... 1
- Which one of the following statements is wrong ? Answer: 3. Eubacteria are also called false bacteria. Key idea: Eubacteria are the true bacteria, not 'false' bacteria. Cyanobacteria are bl... 1
- Which of the following is the most important cause of animals and plants being driven to extinction ? Answer: 3. Habitat loss and fragmentation Key idea: The most important cause of species extinction is habitat loss and fragmentation. Over-e... 1
- Which is the National Aquatic Animal of India ? Answer: 2. River dolphin Key idea: The river dolphin (Gangetic dolphin, Platanista gangetica) is India's National Aquatic Animal, declared i... 1
- Joint Forest Management Concept was introduced in India during : Answer: 3. 1980s Key idea: Joint Forest Management (JFM) was introduced in India in 1980s. It involves local communities in protecting and m... 1
- Which one of the following is a characteristic feature of cropland ecosystem ? Answer: 2. Least genetic diversity Key idea: A cropland is a managed ecosystem where people grow one or a few crop species. This gives the l... 1
- Which of the following is required as inducer(s) for the expression of Lac operon ? Answer: 3. lactose Key idea: In the lac operon, lactose (as allolactose) is the inducer. It binds the repressor protein, which then leaves t... 1
- A tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant. When the F_1 plants were selfed the resulting genotypes were in the ratio of : Answer: 1. 1 : 2 : 1 :: Tall homozygous : Tall heterozygous : Dwarf Key idea: A TT × tt cross gives all Tt in F₁. Selfing F₁ (Tt × Tt) gives... 1
- Match the terms in Column I with their description in Column II and choose the correct option :Column I: (a) Dominance; (b) Codominance; (c) Pleiotropy; (d) Polygenic inheritanceColumn II: (i) Many genes govern a single character; (ii) In a heterozyg… Answer: 2. (ii) (iii) (iv) (i) Key idea: Match each term with its meaning. Dominance: in a heterozygote only one allele expresses: (ii) Codo... 1
- Pick out the correct statements :(a) Haemophilia is a sex-linked recessive disease.(b) Down's syndrome is due to aneuploidy.(c) Phenylketonuria is an autosomal recessive gene disorder.(d) Sickle cell anaemia is an X - linked recessive gene disorder. Answer: 4. (a), (b) and (c) are correct. Key idea: Check each statement. (a) Haemophilia is X-linked recessive: correct. (b) Down syndrome i... 1
- A complex of ribosomes attached to a single strand of RNA is known as : Answer: 1. Polysome Key idea: Several ribosomes attached to one mRNA strand make a polysome (polyribosome), so many copies of a polypeptide... 1
- The *Avena* curvature is used for bioassay of : Answer: 3. IAA Key idea: The Avena (oat coleoptile) curvature test is a bioassay for the auxin IAA. Auxin placed on one side of a decapitate... 1
- The standard petal of a papilionaceous corolla is also called : Answer: 3. Vexillum Key idea: In a papilionaceous corolla (pea family), the large back petal is the standard or vexillum. There are two late... 1
- Tricarpellary, syncarpous gynoecium is found in flowers of : Answer: 1. Liliaceae Key idea: Liliaceae flowers have a tricarpellary, syncarpous gynoecium (superior ovary). Solanaceae has a bicarpellary... 1
- Proximal end of the filament of stamen is attached to the : Answer: 4. Thalamus or petal Key idea: A stamen has an anther (distal) and a filament (long, stalk-like). The proximal end of the filament a... 1
- In higher vertebrates, the immune system can distinguish self-cells and non-self. If this property is lost due to genetic abnormality and it attacks self-cells, then it leads to : Answer: 3. Auto-immune disease Key idea: When the immune system attacks the body's own cells, it is an auto-immune disease. Examples are rhe... 1
- The taq polymerase enzyme is obtained from : Answer: 1. *Thermus aquaticus* Key idea: Taq polymerase comes from the thermophilic bacterium Thermus aquaticus. It is stable at the high te... 1