#neet
- Which of the following is a restriction endonuclease ? Answer: 1. Hind II Hind II is a restriction endonuclease, an enzyme from bacteria that cuts DNA at specific recognition sequences. Protease... 1
- The term ecosystem was coined by : Answer: 2. A.G. Tansley The term "ecosystem" was coined by A.G. Tansley (1935). Odum is known for ecosystem studies and the textbook "Fundam... 1
- In bryophytes and pteridophytes, transport of male gametes requires : Answer: 4. Water In bryophytes and pteridophytes the male gametes (antherozoids) are flagellated and swim through water to reach the egg, so... 1
- Which one of the following is the starter codon ? Answer: 1. AUG AUG codes for methionine and is the start (initiator) codon. UAA, UAG and UGA are stop codons. 1
- 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
- Which part of the tobacco plant is infected by *Meloidogyne incognita* ? Answer: 4. Root Key idea: The nematode Meloidogyne incognita infects the roots of tobacco. It causes root-knot galls and reduces yield. In b... 1
- Antivenom injection contains preformed antibodies while polio drops that are administered into the body contain : Answer: 4. Attenuated pathogens Key idea: Antivenom gives readymade antibodies (passive immunity), while polio drops contain attenuated (wea... 1
- Which one of the following cell organelles is enclosed by a single membrane ? Answer: 3. Lysosomes Lysosomes are single-membrane sacs, so the answer is option 3. Mitochondria and chloroplasts are enclosed by a double m... 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 of the following is not a stem modification ? Answer: 1. Pitcher of Nepenthes The pitcher of Nepenthes is a modified leaf, not a stem. Thorns of citrus: modified axillary buds (stem). Te... 1
- Water soluble pigments found in plant cell vacuoles are : Answer: 4. Anthocyanins Anthocyanins are water-soluble pigments dissolved in the cell sap of vacuoles and give red, blue and purple colours... 1
- Select the correct statement: Answer: 3. Sequoia is one of the tallest trees Sequoia (the redwood, a gymnosperm) is among the tallest trees, so option 3 is correct. 1: Gy... 1
- Which of the following is not required for any of the techniques of DNA fingerprinting available at present ? Answer: 2. Zinc finger analysis DNA fingerprinting uses PCR (to amplify VNTR/STR regions), restriction enzymes (to cut DNA) and DNA-DNA hybr... 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
- A plant in your garden avoids photorespiratory losses, has improved water use efficiency, shows high rates of photosynthesis at high temperatures and has improved efficiency of nitrogen utilisation. In which of the following physiological groups woul… Answer: 2. C ₄ The listed features are the hallmarks of C₄ plants. C₄ plants have Kranz anatomy and PEP carboxylase, which fixes CO₂ in meso... 1
- Which of the following structures is homologus to the wing of a bird ? Answer: 4. Flipper of Whale Homologous organs share the same basic anatomical plan (here the forelimb bones) but may differ in function. A b... 1
- Which of the following characteristic features always holds true for the corresponding group of animals ?(1) Cartilaginous endoskeleton | Chondrichthyes(2) Viviparous | Mammalia(3) Possess a mouth with an upper and a lower jaw | Chordata(4) 3 - chamb… Answer: 1. Cartilaginous endoskeleton - Chondrichthyes Class Chondrichthyes (sharks, rays) always has a cartilaginous endoskeleton. 2: Not a... 1
- Which of the following statements is not true for cancer cells in relation to mutations ? Answer: 4. Mutations inhibit production of telomerase. Cancer cells show reactivation of telomerase, which keeps telomeres from shortening a... 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
- Following are the two statements regarding the origin of life :(a) The earliest organisms that appeared on the earth were non-green and presumably anaerobes.(b) The first autotrophic organisms were the chemoautotrophs that never released oxygen.Of th… Answer: 3. Both (a) and (b) are correct. Both statements are correct. Life began in an oxygen-free atmosphere, so the first cells were non-g... 1
- Reduction in pH of blood will : Answer: 3. decrease the affinity of hemoglobin with oxygen. A fall in blood pH (more H⁺, higher CO₂) shifts the oxygen dissociation curve to... 1
- Which one of the following statements is wrong ? Answer: 4. Glycine is a sulphur containing amino acid. Glycine is the simplest amino acid, with H as its R group, and has no sulphur. The su... 1
- When does the growth rate of a population following the logistic model equal zero ? The logistic model is given as dN/dt = rN(1-N/K) : Answer: 1. when N/K is exactly one. Logistic growth: dN/dt=rN(1-N/K) . The growth rate is zero when 1-N/K=0 , that is when N/K=1 exactly (N... 1
- Which one of the following statements is not true ? Answer: 1. Tapetum helps in the dehiscence of anther The tapetum nourishes the developing pollen grains; it does not help in anther dehiscen... 1