Botany
- Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R).Assertion (A) : Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus.Reason (R) : Presence of more than one nuc… Answer: 1. Both A and R are true and R is the correct explanation of A Key idea: The tapetum is the innermost wall layer of the anther and n... 1
- How many meiotic and mitotic divisions need to occur for the development of a mature female gametophyte from the megaspore mother cell in an angiosperm plant? Answer: 3. 1 Meiosis and 3 Mitosis Key idea: Count divisions from megaspore mother cell (MMC) to the 7-celled, 8-nucleate embryo sac. MMC un... 1
- Which of the following is an example of a zygomorphic flower? Answer: 3. Pea Key idea: A zygomorphic flower can be divided into two equal halves in only one vertical plane. Pea (papilionaceous corolla)... 1
- Match List I with List II :List I: A. Scutellum B. Non-albuminous seed C. Epiblast D. PerispermList II: I. Persistent nucellus II. Cotyledon of Monocot seed III. Groundnut IV. Rudimentary cotyledonChoose the option with all correct matches. Answer: 1. A-II, B-III, C-IV, D-I Key idea: Seed structure terms. Scutellum is the single cotyledon of a monocot (grass) seed: A-II. Non-alb... 1
- Which of following organisms cannot fix nitrogen?A. AzotobacterB. OscillatoriaC. AnabaenaD. VolvoxE. NostocChoose the correct answer from the options given below: Answer: 2. D only Key idea: Volvox is a green alga and cannot fix nitrogen. Azotobacter (free-living bacterium) and Oscillatoria, Anabaena,... 1
- Match List - I with List - II.List - I: A. Centromere; B. Cilium; C. Cristae; D. Cell membraneList - II: I. Mitochondrion; II. Cell division; III. Cell movement; IV. Phospholipid BilayerChoose the correct answer from the options given below : Answer: 4. A-II, B-III, C-I, D-IV Centromere: cell division (II) Cilium: cell movement (III) Cristae: mitochondrion (I) Cell membrane: phosp... 1
- A specialised membranous structure in a prokaryotic cell which helps in cell wall formation, DNA replication and respiration is : Answer: 1. Mesosome Key idea: Mesosomes are infoldings of the plasma membrane in prokaryotes. They help in cell wall formation, DNA replicat... 1
- Name the class of enzyme that usually catalyze the following reaction :S – G + S# → S + S# – GWhere, G → a group other than hydrogenS → a substrateS# → another substrate Answer: 3. Transferase Key idea: Transferases move a group (not hydrogen) from one substrate to another. The reaction S-G + S# → S + S#-G tr... 1
- Which one of the following enzymes contains 'Haem' as the prosthetic group? Answer: 4. Catalase Key idea: Catalase contains a haem group as its prosthetic group. RuBisCO has none, carbonic anhydrase uses zinc, and su... 1
- The correct sequence of events in the life cycle of bryophytes isA. Fusion of antherozoid with egg.B. Attachment of gametophyte to substratum.C. Reduction division to produce haploid spores.D. Formation of sporophyte.E. Release of antherozoids into w… Answer: 3. B, E, A, D, C Key idea: In bryophytes, the gametophyte is dominant and the sporophyte depends on it. B: gametophyte attaches to t... 1
- Given below are the stages in the life cycle of pteridophytes. Arrange the following stages in the correct sequence.A. Prothallus stageB. Meiosis in spore mother cellsC. FertilisationD. Formation of archegonia and antheridia in gametophyte.E. Transfe… Answer: 1. B, A, D, E, C Key idea: In pteridophytes the dominant sporophyte makes spores by meiosis, which grow into the gametophyte. B: mei... 1
- What is the pattern of inheritance for polygenic trait? Answer: 2. Non-mendelian inheritance pattern Key idea: Polygenic traits are controlled by many genes, each with a small additive effect, and... 1
- Given below are two statements :Statement I : Transfer RNAs and ribosomal RNA do not interact with mRNA.Statement II : RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence.In the light of the above statement… Answer: 4. Statement I is incorrect but statement II is correct Key idea: tRNA and rRNA do interact with mRNA during translation. Statement... 1
- Which of the following are the post-transcriptional events in an eukaryotic cell?A. Transport of pre-mRNA to cytoplasm prior to splicing.B. Removal of introns and joining of exons.C. Addition of methyl group at 5' end of hnRNA.D. Addition of adenine… Answer: 2. B, C, D only Key idea: Post-transcriptional processing of hnRNA includes splicing (B), 5' capping with methylguanosine (C) and ta... 1
- Match List I with List II :List I: A. Chlorophyll a; B. Chlorophyll b; C. Xanthophylls; D. CarotenoidsList II: I. Yellow-green; II. Yellow; III. Blue-green; IV. Yellow to Yellow-orangeChoose the option with all correct matches. Answer: 2. A-III, B-I, C-II, D-IV Chlorophyll a: blue-green (III) Chlorophyll b: yellow-green (I) Xanthophylls: yellow (II) Carotenoids: yel... 1
- Which one of the following phytohormones promotes nutrient mobilization which helps in the delay of leaf senescence in plants? Answer: 4. Cytokinin Key idea: Cytokinins delay leaf senescence by promoting nutrient mobilisation. Ethylene and abscisic acid promote senes... 1
- Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R).Assertion (A) : A typical unfertilised, angiosperm embryo sac at maturity is 8 nucleate and 7-celled.Reason (R) : The egg apparatus has 2 polar… Answer: 3. A is true but R is false Key idea: The mature embryo sac is 7-celled and 8-nucleate, so A is true. The reason is false: the egg a... 1
- In the seeds of cereals, the outer covering of endosperm separates the embryo by a protein-rich layer called : Answer: 4. Aleurone layer Key idea: The aleurone layer is the outer protein-rich layer of the endosperm in cereal grains, separating it from... 1
- Find the statement that is NOT correct with regard to the structure of monocot stem. Answer: 1. Hypodermis is parenchymatous. Key idea: In a monocot stem the hypodermis is sclerenchymatous, not parenchymatous. The other state... 1
- Which of the following is an example of non-distilled alcoholic beverage produced by yeast? Answer: 3. Beer Key idea: Beer and wine are made by fermentation without distillation. Whisky, brandy and rum are made by fermentation follo... 1
- Streptokinase produced by bacterium Streptococcus is used for Answer: 4. Removing clots from blood vessels Key idea: Streptokinase is a clot buster. It is produced by Streptococcus and is used as a medi... 1
- From the statements given below choose the correct option :A. The eukaryotic ribosomes are 80S and prokaryotic ribosomes are 70S.B. Each ribosome has two sub-units.C. The two sub-units of 80S ribosome are 60S and 40S while that of 70S are 50S and 30S… Answer: 1. A, B, C are true Key idea: Eukaryotic ribosomes are 80S, made of 60S and 40S subunits. Prokaryotic ribosomes are 70S, made of 50S... 1
- Which one of the following statements refers to Reductionist Biology? Answer: 1. Physico-chemical approach to study and understand living organisms. Key idea: Reductionist biology explains living organisms by s... 1
- Which one of the following is an example of ex-situ conservation? Answer: 3. Zoos and botanical gardens Key idea: Ex-situ conservation means protecting species outside their natural habitat. Zoos and botani... 1