NEET Botany 4 — Questions and Answers
Question 1: Which of the following is a nitrogen-fixing non-leguminous plant?
- Cycas (Correct answer)
- Pinus
- Ficus
- Eucalyptus
Correct answer: Cycas
Cycas has coralloid roots that harbor Anabaena (a cyanobacterium) which fixes atmospheric nitrogen, making it a nitrogen-fixing non-leguminous plant.
Question 2: In angiosperms, the endosperm is:
- Diploid (2n)
- Haploid (n)
- Triploid (3n) (Correct answer)
- Tetraploid (4n)
Correct answer: Triploid (3n)
Endosperm in angiosperms is triploid (3n), formed by the fusion of the second male gamete with the two polar nuclei during double fertilization.
Question 3: The opening of stomata is triggered by:
- Increased CO2 concentration in guard cells
- Decrease in turgor pressure of guard cells
- Accumulation of K+ ions in guard cells (Correct answer)
- Darkness
Correct answer: Accumulation of K+ ions in guard cells
K+ ions accumulate in guard cells in response to light, increasing osmotic pressure and turgor, which causes the stomata to open.
Question 4: Which of the following is characteristic of a zygomorphic flower?
- Radial symmetry
- Bilateral symmetry (Correct answer)
- No plane of symmetry
- More than two planes of symmetry
Correct answer: Bilateral symmetry
A zygomorphic flower has bilateral symmetry and can be divided into two equal halves by only one plane, as seen in pea and bean flowers.
Question 5: Which of the following correctly describes a ligule in grasses?
- A small membranous outgrowth at the leaf-sheath junction (Correct answer)
- A modified leaf that protects the axillary bud
- A structure that aids in seed dispersal
- The enlarged basal portion of a leaf
Correct answer: A small membranous outgrowth at the leaf-sheath junction
A ligule is a thin, membranous or hairy outgrowth found at the junction of the leaf blade and leaf sheath in grasses.
Question 6: Photorespiration in C3 plants leads to:
- Increased photosynthetic efficiency
- Loss of fixed carbon and energy (Correct answer)
- Increased production of ATP
- Better adaptation to high CO2 environments
Correct answer: Loss of fixed carbon and energy
Photorespiration occurs when RuBisCO reacts with O2 instead of CO2, resulting in loss of previously fixed carbon and wasteful consumption of ATP and NADPH.
Question 7: Which part of the plant is used in the commercial extraction of rubber from Hevea brasiliensis?
- Roots
- Latex from phloem (bark) (Correct answer)
- Seeds
- Leaves
Correct answer: Latex from phloem (bark)
Rubber is extracted from latex, a milky fluid found in the laticiferous vessels of the phloem in the bark of Hevea brasiliensis.
NEET Botany 4
Which of the following is a nitrogen-fixing non-leguminous plant?