Chapter 3 — Reproduction in Living Organisms · Biology. These are 10 questions from the Magmo3 bank on this lesson, from easy to hard. Solve each one, then open "Show answer and explanation". Magmo3 has 40 questions on this lesson, each with an explanation.
After fertilization, the ovule turns into a...
Correct answer: (B) Seed
Explanation: The fertilized ovule grows and becomes a seed, while the surrounding ovary becomes the fruit.
Inside which part of the flower are the pollen grains formed?
Correct answer: (A) The anther
Explanation: The anther contains the pollen sacs that produce the pollen grains.
The transfer of pollen grains from the anther to the stigma is called...
Correct answer: (A) Pollination
Explanation: Pollination is the transfer of pollen grains from the anther to the stigma, and it happens before fertilization.
The generative nucleus in a pollen grain divides to form...
Correct answer: (C) Two male nuclei
Explanation: The generative nucleus divides to give two male nuclei that take part in double fertilization.
What are the characteristics of insect-pollinated flowers?
Correct answer: (D) Coloured petals, nectar and a scent
Explanation: Insect-pollinated flowers are colourful and have nectar and a scent to attract insects, and their pollen is sticky so it clings to the insect's body.
A mature pollen grain contains two nuclei, which are...
Correct answer: (B) The tube (vegetative) nucleus and the generative nucleus
Explanation: A pollen grain contains the tube (vegetative) nucleus, which guides the pollen tube, and the generative nucleus, which gives rise to the two male nuclei.
The transfer of pollen grains to the stigma of a flower on another plant of the same species is called ... pollination.
Correct answer: (B) cross
Explanation: Cross-pollination occurs between two plants of the same species, whereas self-pollination occurs within the same flower or the same plant.
A pea pod contains 6 seeds. What is the minimum number of pollen grains that germinated on the stigma, and which part of the flower formed the wall of the pod?
Correct answer: (C) 6 pollen grains, and the ovary wall
Explanation: Each seed develops from one fertilized ovule, and one pollen grain supplies both male nuclei needed for the double fertilization of one ovule, so at least 6 pollen grains are needed. The pod is the fruit, and its wall develops from the ovary wall, while the integuments form the seed coats.
In double fertilization, the first male nucleus fuses with...
Correct answer: (B) The egg cell, forming the zygote
Explanation: The first male nucleus (n) fuses with the egg cell (n) to form the zygote (2n), which develops into the embryo.
A plant that lacks gene G is pollinated with pollen grains that all carry gene G. In which parts of the resulting fruit will gene G be present?
Correct answer: (B) In the embryo and the endosperm only
Explanation: In double fertilization one male nucleus fuses with the egg to form the zygote (embryo) and the other fuses with the two polar nuclei to form the endosperm nucleus, so both receive gene G. The seed coat develops from the ovule integuments and the pericarp from the ovary wall, which are tissues of the mother plant.
The first 10 questions in every subject are free, each with an explanation.