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Question
Explain what you understand by sexual reproduction.
Solution
- Sexual reproduction requires two parents, one male and the other female. The male parent generates the male gamete or sex cell (sperm), whereas the female parent produces the female gamete or egg cell (ovum).
- When sperm and egg cells merge, they generate a third cell called the zygote. Fertilisation is the process by which sperm and egg cells fuse and produce a zygote.
- The zygote is the starting cell of a new creature. It grows into a complete creature throughout time. Sexual reproduction in flowering plants happens through the generation of seeds. Flowers are the primary organs involved in plant sexual reproduction.
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RELATED QUESTIONS
You are asked by your teacher to study the different parts of an embryo of a gram seed. Given below are the steps to be followed for the experiment:
I. Soak the gram seeds in plain water and keep them overnight.
II. Cut open a soaked seed and observe its different parts.
III. Take some dry gram seeds in a petri dish.
IV. Drain the excess water.
V. Cover the soaked seeds with a wet cotton cloth and leave them for a day.
The correct sequence of these steps is :
(A) III, I, V, IV, II
(B) III, I, II, IV, V
(C) III, IV, V, I, II
(D) III, I, IV, V, II
Write the names of those parts of a flower which serve the same function as the following do in the animals :
(i) testis,
(ii) sperm,
(iii) ovary,
(iv) egg
Explain the terms 'cross-pollination'?
Name the part of a seed which contains stored food.
In tobacco plant, the male gametes have 24 chromosomes.
What is the number of chromosomes in the zygote?
(a) Draw a neat diagram of a flower showing its various parts. In this diagram mark stem, receptacle, sepals, petals, stamen and carpel.
(b) What name is given to (i) all the petals of a flower, and (ii) all the sepals of a flower?
(c) What are (i) stamen, and (ii) carpel, in a flower?
(d) What is the other name of carpel of a flower?
(e) What is the name of yellow powdery substance present in the anther of a flower?
Fill in the blank by selecting suitable word:
A flower bearing only male or female parts is known as __________ flower.
Multiple choice question. Tick (✓) the correct choice:
The male gamete is present inside the which germinates.
- the style
- the stigma
- the anther
- the ovary
Where does the endothecium layer of anther lobes is present?
- Assertion: Primary endosperm nucleus is diploid.
- Reason: It is the product of double fertilisation.
