Botany
- Plants which produce characteristic pneumatophores and show vivipary belong to : Answer: 1. Halophytes Mangrove plants live in saline, waterlogged soil. They have pneumatophores (breathing roots) and show vivipary (seed g... 1
- Asymptote in a logistic growth curve is obtained when : Answer: 1. K = N In the logistic growth curve the upper asymptote is reached when the population size N equals the carrying capacity K , so... 1
- Which one from those given below is the period for Mendel's hybridization experiments ? Answer: 4. 1856 - 1863 Mendel carried out his hybridization experiments on garden pea from 1856 to 1863. He published the results in 1866. 1
- Which of the following RNAs should be most abundant in animal cell ? Answer: 4. r-RNA Among cellular RNAs, rRNA makes up about 80% of the total RNA, so it is the most abundant. tRNA is about 15%, and mRNA only... 1
- Which statement is wrong for Krebs' cycle ? Answer: 3. The cycle starts with condensation of acetyl group (acetyl CoA) with pyruvic acid to yield citric acid The wrong statement is opt... 1
- Which of the following is made up of dead cells ? Answer: 2. Phellem Phellem (cork) is made of dead cells with suberin deposits in the walls and no protoplasm. Collenchyma, phloem (sieve ele... 1
- Which of the following in sewage treatment removes suspended solids ? Answer: 2. Primary treatment Primary treatment of sewage is physical: filtration and sedimentation remove floating and suspended solids. Sec... 1
- Which of the following options gives the correct sequence of events during mitosis ? Answer: 1. condensation → nuclear membrane disassembly → arrangement at equator → centromere division → segregation → telophase The correct... 1
- Which of the following components provides sticky character to the bacterial cell ? Answer: 3. Glycocalyx The glycocalyx is the outer layer of the bacterial cell envelope, made of polysaccharide (and sometimes protein). It i... 1
- Viroids differ from viruses in having : Answer: 3. RNA molecules without protein coat Viroids are smaller than viruses: they are infectious RNA molecules and have no protein coat.... 1
- Which of the following are found in extreme saline conditions ? Answer: 4. Archaebacteria Archaebacteria live in harsh habitats: extreme halophiles in very salty places, thermoacidophiles in hot springs,... 1
- Which among the following are the smallest living cells, known without a definite cell wall, pathogenic to plants as well as animals and can survive without oxygen ? Answer: 2. Mycoplasma The description fits Mycoplasma. Smallest living cells. No cell wall, so they are pleomorphic. Pathogenic to plants an... 1
- Life cycle of Ectocarpus and Fucus respectively are : Answer: 2. Haplodiplontic, Diplontic Ectocarpus is a brown alga with alternation of generations, so its life cycle is haplodiplontic. Fucus... 1
- Which one of the following statements is not valid for aerosols ? Answer: 2. They cause increased agricultural productivity Aerosols are fine particles in the air. They change rainfall and monsoon patterns,... 1
- The region of Biosphere Reserve which is legally protected and where no human activity is allowed is known as : Answer: 4. Core zone A biosphere reserve has three zones. Core zone: legally protected, no human activity allowed. Buffer zone: limited rese... 1
- Mycorrhizae are the example of : Answer: 3. Mutualism Mycorrhizae are associations between fungi and roots of higher plants, and both partners benefit. The fungus absorbs ph... 1
- The genotypes of a Husband and Wife are I^AI^B and I^Ai.Among the blood types of their children, how many different genotypes and phenotypes are possible ? Answer: 2. 4 genotypes ; 3 phenotypes Write the Punnett cross of the parents and count the distinct genotypes and blood groups. Gametes: I^A... 1
- The final proof for DNA as the genetic material came from the experiments of : Answer: 1. Hershey and Chase Hershey and Chase used radioactive ³²P (labels DNA) and ³⁵S (labels protein) in bacteriophages. Only the DNA en... 1
- If there are 999 bases in an RNA that codes for a protein with 333 amino acids, and the base at position 901 is deleted such that the length of the RNA becomes 998 bases, how many codons will be altered ? Answer: 2. 33 Deleting one base causes a frameshift, so every codon after the deletion point is read differently. Codon 300 covers bases 898... 1
- With reference to factors affecting the rate of photosynthesis, which of the following statements is not correct ? Answer: 2. C₃ plants respond to higher temperatures with enhanced photosynthesis while C₄ plants have much lower temperature optimum The wro... 1
- Fruit and leaf drop at early stages can be prevented by the application of : Answer: 2. Auxins Auxins prevent early fruit and leaf drop (abscission) in plants. Ethylene promotes abscission and ripening, so it does the... 1
- Functional megaspore in an angiosperm develops into : Answer: 2. Embryo sac The functional megaspore divides mitotically to form the female gametophyte, the embryo sac. Endosperm and embryo form... 1
- A dioecious flowering plant prevents both : Answer: 1. Autogamy and geitonogamy A dioecious plant bears male and female flowers on separate plants. Autogamy (pollen to stigma of the sa... 1
- Attractants and rewards are required for : Answer: 1. Entomophily Insect pollinated flowers (entomophily) need attractants such as colour and scent and rewards such as nectar and poll... 1