Apomixis

Q.

What is apomixis and what is its importance?

Q. During the formation of embryo sac, the functional megaspore undergoes:

1. Two mitotic divisions
2. Two meiotic divisions
3. Three meiotic divisions
4. Three mitotic divisions

Q. Differentiate between Parthenocarpy and Parthenogenesis. Give one example of each. [3]

Q. (a) Explain post pollination events leading to seed production in angiosperms
(b) List the different types of pollination depending on the source of pollen grain [5]

Q. I didn't understand the statement given in NCERT class 12 textbook in page number 37.. the sentence goes like this... seeds offer several advantages to angiosperms, firstly since reproductive processes such as pollination and fertilization are independent of water , seed formation is more dependable

​​​ed formation is more dependable even though the pollination and fertilization are independent of water

Q. Adventive embryony in Citrus is due to:

1. Nucellus or maternal sporophytic tissues in ovule
2. Integuments
3. Zygotic embryo
4. Fertilised egg

Q.

Agamospermy includes

1. Adventive polyembryony

2. Recurrent apomixis

3. Nonrecurrent apomixis

4. All the above

Q. Apomixis is a type of reproduction that results in the development of a/an

1. New seed with fusion of gametes
2. Embryo from nucellus
3. New seed without fusion of gametes
4. Embryo from endosperm

Q. The 2 polar-nuclei present in the embryo sac of angiosperms are derived from which of the following ends?

1. Both from micropylar end
2. Both from chalazal end
3. One each from micropylar and chalazal end
4. None of the above

Q. Match the following:

$\begin{array}{cccc}a& \text{Polyembryony}& \text{i}& \text{Beet}\\ \text{b}& \text{Apomixis}& \text{ii}& \text{Grasses}\\ \text{c}& \text{Lupine}& \text{iii}& \text{Orange}\\ \text{d}& \text{Perisperm}& \text{iv}& \text{Longest period}\\ & & & \text{of dormancy}\end{array}$

1. a-(i), b-(iii), c-(ii), d-(iv)
2. a-(ii), b-(iii), c-(i), d-(iv)
3. a-(iii), b-(ii), c-(i), d-(iv)
4. a-(iii), b-(ii), c-(iv), d-(i)

Q. Nucellar embryo is

1. Amphimictic haploid
2. Amphimictic diploid
3. Apomictic haploid
4. Apomictic diploid.

Q. 10 seeds collected from a Citrus fruit are likely to have how many embryos?

1. 9
2. 8
3. 5
4. More than 10

Q. Mendel’s laws of inheritance are applicable on the plants which
(1) reproduce asexually
(2) reproduce sexually
(3) reproduce vegetatively
(4) all of the above plants

Q. What is apomixis? Mention its significance.

Q.

Few flowering plants like Sunflower have formulated a special mechanism of producing seeds without fertilisation called __.

Q. Seed formation without fertilization in flowering plants involves the process of:

1. sporulation
2. budding
3. somatic hybridization
4. apomixis

Q.

Which of the following terms is used to describe the component isolated from a plant for culturing in the specific medium?

1. Explant

2. Synthetic seeds

3. Callus

4. Embryoid

Q. How is the embryo formed from the zygote in angiosperms?

1. By meiotic divisions.
2. By mitotic divisions.
3. By mitotic divisions followed by meiotic divisions.
4. By meiotic divisions followed by mitotic divisions.

Q. Which one produces embryo sac?

1. Megaspore mother cell
2. Megaspore
3. Microspore
4. Embryo cell

Q. Adventive embryony in Citrus is due to:

1. Nucellus or maternal sporophytic tissues in ovule
2. Integuments
3. Zygotic embryo
4. Fertilised egg

Q. Fertilization is essential for the production of seeds but in some angiospermic seeds develop without fertilization.
Give an example of angiosperm that produces seeds without fertilization. Name the process.

Q.

What is pollination? How does it occur in plants? How does pollination lead to fertilization? Explain.

Q. Sexual reproduction is better mode of reproduction because

1. are bigger in size
2. Faster mode of reproduction
3. off spring have better chances of survival
4. are identical to one another

Q. Match the following:

$\begin{array}{cccc}a& \text{Polyembryony}& \text{i}& \text{Beet}\\ \text{b}& \text{Apomixis}& \text{ii}& \text{Grasses}\\ \text{c}& \text{Lupine}& \text{iii}& \text{Orange}\\ \text{d}& \text{Perisperm}& \text{iv}& \text{Longest period}\\ & & & \text{of dormancy}\end{array}$

1. a-(i), b-(iii), c-(ii), d-(iv)
2. a-(iii), b-(ii), c-(iv), d-(i)
3. a-(iii), b-(ii), c-(i), d-(iv)
4. a-(ii), b-(iii), c-(i), d-(iv)

Q. State what is apomixis. Comment on its significance. How can it be commercially used?

Q. Match the following:

$\begin{array}{cccc}a& \text{Polyembryony}& \text{i}& \text{Beet}\\ \text{b}& \text{Apomixis}& \text{ii}& \text{Grasses}\\ \text{c}& \text{Lupine}& \text{iii}& \text{Orange}\\ \text{d}& \text{Perisperm}& \text{iv}& \text{Longest period}\\ & & & \text{of dormancy}\end{array}$

1. a-(i), b-(iii), c-(ii), d-(iv)
2. a-(iii), b-(ii), c-(iv), d-(i)
3. a-(iii), b-(ii), c-(i), d-(iv)
4. a-(ii), b-(iii), c-(i), d-(iv)

Q. Apomixis is:

1. formation of seeds by fusion of gametes
2. formation of seeds with syngamy but no meiosis
3. formation of seeds without syngamy and meiosis
4. none of these.

Q.

What is polyembryony ? Give one example.

What is polyembryony ? Give one example.

Q. Assertion :Apomixis is very important in hybrid seed industry. Reason: Apomixis is a form of sexual reproduction that mimics asexual reproduction.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Distinguish between asexual and sexual reproduction. Why is vegetative reproduction also considered as a type of asexual reproduction?