NEET UG
- In angiosperm, the haploid, diploid and triploid structures of a fertilized embryo sac sequentially are : Answer: 4. Synergids, Zygote and Primary endosperm nucleus Key idea: In a fertilised embryo sac, count ploidy for each structure. Synergids:... 1
- What is the function of tassels in the corn cob? Answer: 3. To trap pollen grains Key idea: In maize (corn) the tassels are the long, silky styles and stigmas of the female inflorescence (c... 1
- Large, colourful, fragrant flowers with nectar are seen in : Answer: 2. insect pollinated plants Key idea: Insect-pollinated flowers are large, colourful and fragrant, and offer nectar as a reward. Win... 1
- Axile placentation is observed in Answer: 1. China rose, Petunia and Lemon Key idea: Axile placentation (ovary with two or more chambers, ovules on central axis) is found in... 1
- Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R :Assertion A : Late wood has fewer xylary elements with narrow vessels.Reason R : Cambium is less active in winters.In the light of the above statem… Answer: 2. Both A and R are true and R is the correct explanation of A. Key idea: In winter the cambium is less active and forms fewer xylar... 1
- Given below are two statements :Statement I : Endarch and exarch are the terms often used for describing the position of secondary xylem in the plant body.Statement II : Exarch condition is the most common feature of the root system.In the light of t… Answer: 1. Statement I is incorrect but Statement II is true. Key idea: Endarch and exarch describe the position of primary xylem. Statement... 1
- Identify the correct statements :A. Lenticels are the lens-shaped openings permitting the exchange of gases.B. Bark formed early in the season is called hard bark.C. Bark is a technical term that refers to all tissues exterior to vascular cambium.D.… Answer: 3. A and D only Key idea: Check each statement. A is true: lenticels allow gas exchange. B is false: bark formed early in the season... 1
- In gene gun method used to introduce alien DNA into host cells, microparticles of ________ metal are used. Answer: 4. Tungsten or gold Key idea: In the biolistic (gene gun) method, DNA is coated on microscopic particles of tungsten or gold, which... 1
- Main steps in the formation of Recombinant DNA are given below. Arrange these steps in a correct sequence.A. Insertion of recombinant DNA into the host cell.B. Cutting of DNA at specific location by restriction enzyme.C. Isolation of desired DNA frag… Answer: 2. B, C, D, A or 4. C, B, D, A Key idea: A recombinant DNA is made by cutting the DNA, getting the desired fragment, amplifying it,... 1
- Cellulose does not form blue colour with Iodine because Answer: 4. It does not contain complex helices and hence cannot hold iodine molecules. Key idea: The blue colour of the starch-iodine test c... 1
- Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R :Assertion A : The first stage of gametophyte in the life cycle of moss is protonema stage.Reason R : Protonema develops directly from spores produc… Answer: 2. Both A and R are correct and R is the correct explanation of A. Key idea: In mosses the haploid spore germinates into a creeping,... 1
- The thickness of ozone in a column of air in the atmosphere is measured in terms of : Answer: 2. Dobson units Key idea: Ozone thickness in a column of air is measured in Dobson units (DU). Kilobase measures DNA length, decibel... 1
- Among 'The Evil Quartet', which one is considered the most important cause driving extinction of species? Answer: 2. Habitat loss and fragmentation Key idea: Of the four causes in the "Evil Quartet", habitat loss and fragmentation is the most imp... 1
- Frequency of recombination between gene pairs on same chromosome as a measure of the distance between genes to map their position on chromosome, was used for the first time by Answer: 4. Alfred Sturtevant Key idea: Alfred Sturtevant, a student of T. H. Morgan, used the frequency of recombination between gene pairs... 1
- How many ATP and NADPH_2 are required for the synthesis of one molecule of Glucose during Calvin cycle? Answer: 3. 18 ATP and 12 NADPH ₂ Key idea: One CO₂ fixed in the Calvin cycle needs 3 ATP and 2 NADPH. Glucose has 6 carbons, so 6 turns are... 1
- Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R :Assertion A : ATP is used at two steps in glycolysis.Reason R : First ATP is used in converting glucose into glucose-6-phosphate and second ATP is… Answer: 2. Both A and R are true and R is the correct explanation of A. Key idea: Two ATP molecules are invested in the preparatory phase of... 1
- Which micronutrient is required for splitting of water molecule during photosynthesis? Answer: 2. manganese Key idea: Manganese (Mn) is needed for the water-splitting (photolysis) step of the light reaction, which releases O₂ ,... 1
- Which hormone promotes internode/petiole elongation in deep water rice? Answer: 4. Ethylene Key idea: In deep water rice, submergence raises ethylene levels, and ethylene promotes rapid elongation of internodes a... 1
- Family Fabaceae differs from Solanaceae and Liliaceae. With respect to the stamens, pick out the characteristics specific to family Fabaceae but not found in Solanaceae or Liliaceae. Answer: 2. Diadelphous and Dithecous anthers Key idea: Fabaceae has diadelphous stamens (9 + 1) with dithecous anthers. Solanaceae and Lilia... 1
- The equilibrium concentrations of the species in the reaction A + B ⇌ C + D are 2, 3, 10 and 6 mol L^-1, respectively at 300 K. Δ G^° for the reaction is (R = 2 cal / mol K) Answer: 4. -1381.80 cal Key idea: Δ G^° = -2.303 RTlog K . K = [C][D]/[A][B] = 10 × 6/2 × 3 = 10 , so log K = 1 . Δ G^° = -2.303 × 2 × 300 ×... 1
- Which complex compound is most stable? Answer: 4. [CoCl₂(en)₂]NO₃ Key idea: A chelating ligand makes a complex more stable (chelate effect). In [CoCl₂(en)₂]NO₃ , the ligand en (et... 1
- The reaction that does NOT take place in a blast furnace between 900 K to 1500 K temperature range during extraction of iron is : Answer: 2. Fe ₂ O ₃ + CO → 2FeO + CO ₂ Key idea: The blast furnace has temperature zones: the reduction of Fe₂O₃ to FeO by CO takes place in... 1
- Consider the following compounds/species :i. naphthalene ii. cyclopentadienyl anion iii. cyclobutadiene iv. cyclopropenyl anion v. cyclopropenyl cation vi. cyclooctatetraene vii. anthracene (all drawn as structures)The number of compounds/species whi… Answer: 2. 4 Key idea: Hückel's rule: a planar, cyclic, fully conjugated species with (4n+2) π electrons is aromatic. i. Naphthalene: 10 π e... 1
- Pumice stone is an example of - Answer: 4. solid sol Key idea: Name a colloid by its dispersed phase and dispersion medium. Pumice stone is a solid that traps gas, so gas i... 1