Botany
- Stems modified into flat green organs performing the functions of leaves are known as : Answer: 3. Phylloclades Flat, green stems that do the work of leaves (photosynthesis) are phylloclades, e.g. Opuntia. Cladodes: short stem b... 1
- Specialised epidermal cells surrounding the guard cells are called : Answer: 2. Subsidiary cells Epidermal cells around the guard cells, which differ from other epidermal cells, are subsidiary cells. Bulliform... 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
- 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
- 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
- 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
- Nomenclature is governed by certain universal rules. Which one of the following is contrary to the rules of nomenclature ? Answer: 1. Biological names can be written in any language Biological names must be in Latin (or Latinised) form, whatever the language of t... 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
- Which of the following would appear as the pioneer organisms on bare rocks ? Answer: 1. Lichens On bare rock, lichens are the pioneer species of primary succession. They secrete acids, weather the rock and form soil,... 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 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 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
- 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 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
- 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
- Spindle fibres attach on to : Answer: 2. Kinetochore of the chromosome Key idea: Spindle fibres attach to the kinetochore. The kinetochore is a disc-shaped protein struct... 1
- In meiosis crossing over is initiated at : Answer: 1. Pachytene Key idea: Crossing over takes place at pachytene. At pachytene (prophase I), recombination nodules form and the enzyme... 1
- Microtubules are the constituents of : Answer: 2. Spindle fibres, Centrioles and Cilia Key idea: Microtubules make up spindle fibres, centrioles (and basal bodies), and the axonem... 1
- One of the major components of cell wall of most fungi is : Answer: 1. Chitin Key idea: The fungal cell wall is made mostly of chitin (a polymer of N-acetylglucosamine) and polysaccharides. Peptidogly... 1
- Which one of the following statements is wrong ? Answer: 3. Eubacteria are also called false bacteria. Key idea: Eubacteria are the true bacteria, not 'false' bacteria. Cyanobacteria are bl... 1
- Which of the following is the most important cause of animals and plants being driven to extinction ? Answer: 3. Habitat loss and fragmentation Key idea: The most important cause of species extinction is habitat loss and fragmentation. Over-e... 1
- Which is the National Aquatic Animal of India ? Answer: 2. River dolphin Key idea: The river dolphin (Gangetic dolphin, Platanista gangetica) is India's National Aquatic Animal, declared i... 1
- Joint Forest Management Concept was introduced in India during : Answer: 3. 1980s Key idea: Joint Forest Management (JFM) was introduced in India in 1980s. It involves local communities in protecting and m... 1