Botany
- The label of a herbarium sheet does not carry information on Answer: 3. height of the plant A herbarium label records the collector's name, date, locality, local name, family and scientific name, habit... 1
- Red List contains data or information on Answer: 2. threatened species The IUCN Red List documents the conservation status of threatened species of plants and animals, with categori... 1
- The term 'polyadelphous' is related to Answer: 1. androecium Polyadelphous means stamens united by their filaments into more than two bundles (for example in Citrus). Stamens belo... 1
- How many plants among *Indigofera*, *Sesbania*, *Salvia*, *Allium*, *Aloe*, mustard, groundnut, radish, gram and turnip have stamens with different lengths in their flowers? Answer: 1. Four Count the plants whose flowers have stamens of unequal length. Salvia: only two stamens, with unequal arms and a lever-like... 1
- Radial symmetry is found in the flowers of Answer: 4. *Brassica* Radial symmetry (actinomorphic) is seen in Brassica (cruciferae). Trifolium and Pisum have zygomorphic papilionaceous... 1
- Free-central placentation is found in Answer: 4. *Dianthus* Free-central placentation, in which ovules sit on a central axis without septa, is found in Dianthus and Primula. Arge... 1
- Cortex is the region found between Answer: 4. epidermis and stele The cortex is the ground tissue that lies between the epidermis and the stele (the vascular region enclosed b... 1
- The balloon-shaped structures called tyloses Answer: 2. are extensions of xylem parenchyma cells into vessels Tyloses are balloon-like outgrowths of xylem parenchyma cells that protrude... 1
- During cell growth, DNA synthesis takes place in Answer: 4. S phase In the cell cycle, DNA replication happens in the S (synthesis) phase of interphase. G₁ is for cell growth and preparing... 1
- A cell organelle containing hydrolytic enzymes is Answer: 4. lysosome Lysosomes are membrane-bound sacs filled with hydrolytic enzymes (acid hydrolases) that digest proteins, lipids, carbohy... 1
- How many hot spots of biodiversity in the world have been identified till date by Norman Myers? Answer: 2. 34 Biodiversity hotspots are regions with very high species richness and many endemic species that are under threat. Norman Myers... 1
- Which of the following is correctly matched? Answer: 2. *Parthenium hysterophorus*—Threat to biodiversity Parthenium hysterophorus (carrot grass) is an invasive weed that threatens nati... 1
- The primary producers of the deep-sea hydrothermal vent ecosystem are Answer: 1. chemosynthetic bacteria No sunlight reaches deep-sea hydrothermal vents. The primary producers are chemosynthetic bacteria, which... 1
- Which of the following is correct for r-selected species? Answer: 4. Large number of progeny with small size r-selected species have a high intrinsic rate of increase: they produce a large number of... 1
- If '+' sign is assigned to beneficial interaction, '–' sign to detrimental and '0' sign to neutral interaction, then the population interaction represented by '+' '–' refers to Answer: 3. parasitism In parasitism the parasite benefits (+) and the host is harmed (−). Amensalism: 0, − Commensalism: +, 0 Mutualism: +,... 1
- The mechanism that causes a gene to move from one linkage group to another is called Answer: 2. translocation A gene moves from one linkage group (chromosome) to another by translocation, the transfer of a chromosome segment... 1
- Taylor conducted the experiments to prove semiconservative mode of chromosome replication on Answer: 1. *Vicia faba* Taylor and co-workers (1957) used radioactive thymidine with root tip cells of Vicia faba (broad bean) to show that... 1
- A true breeding plant is Answer: 2. near homozygous and produces offspring of its own kind A true-breeding line, after repeated self-pollination, is nearly homozygou... 1
- The equivalent of a structural gene is Answer: 1. cistron A cistron is the functional unit of DNA that codes for one polypeptide, so it is equivalent to a structural gene. An oper... 1
- Which of the following rRNAs acts as structural RNA as well as ribozyme in bacteria? Answer: 2. 23 S rRNA In bacteria, the 23S rRNA of the large subunit acts as the peptidyl transferase ribozyme that forms peptide bonds, besi... 1
- Which of the following biomolecules is common to respiration-mediated breakdown of fats, carbohydrates and proteins? Answer: 3. Acetyl CoA Carbohydrates, fats and proteins are all finally oxidised through the Krebs cycle, which they enter as acetyl CoA. Pyr... 1
- The process which makes major difference between C_3 and C_4 plants is Answer: 2. photorespiration The big difference is photorespiration. In C₃ plants RuBisCO also acts as an oxygenase, causing a loss of fixed... 1
- A few drops of sap were collected by cutting across a plant stem by a suitable method. The sap was tested chemically. Which one of the following test results indicates that it is phloem sap? Answer: 1. Alkaline Phloem sap is rich in sugar (mainly sucrose), has a high refractive index because of dissolved solutes, and is alkaline... 1
- Which is essential for the growth of root tip? Answer: 2. Ca Calcium is needed for the formation of the middle lamella (calcium pectate) of the cell wall and for the spindle during cell d... 1