#neet
- Read the following statements and choose the set of correct statements :(a) Euchromatin is loosely packed chromatin(b) Heterochromatin is transcriptionally active(c) Histone octomer is wrapped by negatively charged DNA in nucleosome(d) Histones are r… Answer: 3. (a), (c), (d) Only (a) Euchromatin is loosely packed and transcriptionally active: true. (b) Heterochromatin is densely packed an... 1
- Which one of the following produces nitrogen fixing nodules on the roots of Alnus ? Answer: 3. Frankia Frankia is the actinomycete that forms nitrogen-fixing root nodules in non-leguminous plants such as Alnus. Rhizobium nod... 1
- Identify the incorrect statement related to Pollination : Answer: 1. Moths and butterflies are the most dominant pollinating agents among insects Bees are the dominant insect pollinators, not moths... 1
- Which of the following is not a method of ex situ conservation ? Answer: 3. National Parks National parks protect organisms in their natural habitat, so they are in situ conservation. Cryopreservation, in... 1
- Which one of the following is not true regarding the release of energy during ATP synthesis through chemiosmosis ? It involves : Answer: 3. Breakdown of electron gradient In chemiosmosis, a proton gradient (not an electron gradient) drives ATP synthesis. Protons move a... 1
- Which one of the following statements cannot be connected to Predation ? Answer: 4. Both the interacting species are negatively impacted In predation, one species (predator) benefits (+) and the other (prey) is ha... 1
- Given below are two statements :Statement I :Cleistogamous flowers are invariably autogamousStatement II :Cleistogamy is disadvantageous as there is no chance for cross pollinationIn the light of the above statements, choose the correct answer from t… Answer: 2. Both Statement I and Statement II are correct Statement I: cleistogamous flowers never open, so pollen falls on the stigma of the... 1
- Given below are two statements :Statement I :The primary CO_2 acceptor in C_4 plants is phosphoenolpyruvate and is found in the mesophyll cells.Statement II :Mesophyll cells of C_4 plants lack RuBisCo enzyme.In the light of the above statements, choo… Answer: 2. Both Statement I and Statement II are correct Statement I: in C₄ plants PEP, a three-carbon compound, is the primary CO₂ acceptor... 1
- Identify the correct set of statements :(a) The leaflets are modified into pointed hard thorns in Citrus and Bougainvillea(b) Axillary buds form slender and spirally coiled tendrils in cucumber and pumpkin(c) Stem is flattened and fleshy in Opuntia a… Answer: 4. (b), (c), (d) and (e) Only (a) In Citrus and Bougainvillea, axillary buds (stems) become thorns, not leaflets: false. (b) Axillar... 1
- The gaseous plant growth regulator is used in plants to : Answer: 3. promote root growth and roothair formation to increase the absorption surface The gaseous plant growth regulator is ethylene. It... 1
- Which one of the following plants shows vexillary aestivation and diadelphous stamens ? Answer: 3. Pisum sativum Vexillary (papilionaceous) aestivation with diadelphous stamens (9+1) is typical of the pea family, Fabaceae. Pisum... 1
- What amount of energy is released from glucose during lactic acid fermentation ? Answer: 1. Less than 7% Lactic acid fermentation releases less than 7% of the energy in glucose. Most energy stays in the lactic acid, since... 1
- Given below are two statements :Statement I :Decomposition is a process in which the detritus is degraded into simpler substances by microbes.Statement II :Decomposition is faster if the detritus is rich in lignin and chitinIn the light of the above… Answer: 4. Statement I is correct but Statement II is incorrect Statement I: decomposition breaks detritus into simpler substances through m... 1
- What is the net gain of ATP when each molecule of glucose is converted to two molecules of pyruvic acid ? Answer: 4. Two In glycolysis, one glucose gives two pyruvic acid molecules. 4 ATP are made and 2 ATP are used in the preparatory steps, so t... 1
- Match List - I with List - II.List - I: (a) Manganese (b) Magnesium (c) Boron (d) IronList - II: (i) Activates the enzyme catalase (ii) Required for pollen germination (iii) Activates enzymes of respiration (iv) Functions in splitting of water during… Answer: 3. (a) - (iv), (b) - (iii), (c) - (ii), (d) - (i) Manganese functions in splitting of water in photosynthesis: (a)-(iv). Magnesium a... 1
- Habitat loss and fragmentation, over exploitation, alien species invasion and co-extinction are causes for : Answer: 4. Biodiversity loss Habitat loss and fragmentation, over-exploitation, alien species invasion and co-extinction are the four major... 1
- The process of translation of mRNA to proteins begins as soon as : Answer: 2. The small subunit of ribosome encounters mRNA Translation begins when the small ribosomal subunit binds to the mRNA. Then the ini... 1
- "Girdling Experiment" was performed by Plant Physiologists to identify the plant tissue through which : Answer: 3. food is transported In the girdling experiment, a ring of bark (with phloem) is removed from a stem. Food accumulates above the r... 1
- Given below are two statements :Statement I :Mendel studied seven pairs of contrasting traits in pea plants and proposed the Laws of InheritanceStatement II :Seven characters examined by Mendel in his experiment on pea plants were seed shape and colo… Answer: 2. Both Statement I and Statement II are correct Mendel studied seven pairs of contrasting traits in pea and proposed the laws of in... 1
- In one molal solution that contains 0.5 mole of a solute, there is Answer: 3. 500 g of solvent Key idea: molality = moles of solute per kg of solvent. 1\ m=0.5/w with w in kg gives w=0.5 kg =500 g of solvent... 1
- Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).Assertion (A) : ICl is more reactive than I_2.Reason (R) : I-Cl bond is weaker than I-I bond.In the light of the above statements, choose the mo… Answer: 2. Both (A) and (R) are correct and (R) is the correct explanation of (A) Key idea: interhalogen compounds are more reactive than th... 1
- Gadolinium has a low value of third ionisation enthalpy because of Answer: 3. high exchange enthalpy Key idea: exchange enthalpy stabilises half-filled subshells. Gd is [Xe]4f⁷5d¹6s² . Removing the third ele... 1
- Compound X on reaction with O_3 followed by Zn/H_2O gives formaldehyde and 2-methyl propanal as products. The compound X is : Answer: 2. 3-Methylbut-1-ene Key idea: ozonolysis cuts the C=C bond and puts a C=O on each carbon. Working backwards: HCHO and mathrm(CH₃)₂C... 1
- For a first order reaction A → Products, initial concentration of A is 0.1 M, which becomes 0.001 M after 5 minutes. Rate constant for the reaction in min^-1 is Answer: 3. 0.9212 Key idea: for a first order reaction k=2.303/tlog[A]₀/[A] . k=2.303/5log0.1/0.001=2.303/5×2=0.9212\ mathrmmin⁻¹ . 1