After fertilization, the ovule and ovary subsequently develop to form
- A.seed and fruit respectively
- B.fruit and seed respectively
- C.seed and flower respectively
- D.degenerated ovule and seedless fruit respectively
Correct answer
Explanation
The correct answer is A, seed and fruit respectively. After fertilisation, each ovule grows into a seed, and the ovary that holds the ovules grows into the fruit.
In flowering plants, a pollen tube carries two male gametes to the ovule. One fuses with the egg to form the zygote, which becomes the embryo, and the other fuses with the two polar nuclei to form the endosperm, the food store of the seed; this is double fertilisation. The integuments of the ovule harden into the seed coat, and the wall of the ovary becomes the pericarp, the wall of the fruit. The petals, sepals and stamens usually wither and fall away. Fruits that grow without fertilisation, like seedless bananas, are called parthenocarpic.
B is wrong: it reverses the pair; the ovary becomes the fruit, not the seed.
C is wrong: the flower exists before fertilisation; the ovary does not turn into a flower.
D is wrong: a fertilised ovule develops, it does not degenerate, and normal fruits contain seeds.
Exam tip: Ovule → seed, ovary → fruit, ovary wall → pericarp, integuments → seed coat.
Practice Questions
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1. Hedgehog
2. Marmot
3. Pangolin
To reduce the chance of being captured by predators, which of the above organisms rolls up/roll up and protects/protect its/their vulnerable parts?
- A.1 and 2
- B.2 only
- C.3 only
- D.1 and 3
Show answer
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- C.Lemongrass
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- A.Conducting copper coil
- B.Electric heating coil
- C.Semi conductor diode
- D.Rheostat
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- A.286 u
- B.106 u
- C.83 u
- D.53 u
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- A.Bauxite
- B.Quartz
- C.Feldspar
- D.Pitchblende
Show answer
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