Tag: sexual reproduction in plants

Questions Related to sexual reproduction in plants

In coconut black covering (thin layer) adherent to the kernel around the endosperm is 

  1. Mesocarp

  2. Seed coat

  3. Pericarp

  4. Epicarp


Correct Option: B
Explanation:

In the case of coconut plant, the hard shell forms the inner layer of fruit (endocarp). Inside the shell, there is a seed which is covered by a seed coat. This seed coat is brown in colour and attached to the kernel which is endosperm. The seed coat is a thin layer which is protective in nature. 

Which of the following triggers the ripening of fruits?

  1. Ethylene

  2. Indoleacetic acid

  3. Gibberellic acid

  4. Kinetin


Correct Option: A
Explanation:

Ethylene helps fruits ripen by making them softer, through the breakdown components of the cell walls, and sweeter, through the conversion of starches to sugars. Unlike the other plant hormones, ethylene is actually a gas and is distributed through the air, not through the plant body. One of the coolest things about ethylene is that it is released in a positive feedback loop, a little bit of ethylene causes more to be released, which causes even more to be released, and so on. A benefit of this fact is that you can take an unripe fruit (a pear, plum, or peach, for example) and put it in a paper bag with riper fruit (bananas work well for this) and ethylene will accumulate, making the unripe fruit soft and sweet. Indoleacetic acid, gibberellic acid and kinetin does not triggers the ripening process. 

Hence, the correct answer is option A.

Parthenogenesis is the development of

  1. Fruit without hormones

  2. Fruit without fertilisation

  3. Egg without fertilisation

  4. Embryo without fertilisation


Correct Option: C
Explanation:

Parthenogenesis is a type of asexual reproduction in which the offspring develops from unfertilized eggs. It is particularly common among arthropods and can also be found in some species of fish, amphibians, birds and reptiles, but not in mammals. 

Therefore, the correct answer is option C.

Mature fruit is ________

  1. Transformed sepal

  2. Transformed ovule

  3. Transformed ovary

  4. All of the above


Correct Option: C
Explanation:

Ovary get transformed into fruit post fertilisation. Outer layer of ovary becomes the outer layer of fruit along with ovules converting into seeds.

Ovules convert into ................. in the mature fruit.

  1. Seeds

  2. Fruits

  3. Stamens

  4. All of the above


Correct Option: A
Explanation:

Ovules form into seeds in the mature fruit post fertilisation (transformed ovary). Their different arrangements can be seen in fruits such as pea, orange etc.

In an angiospermic plant, endosperm is formed due to fertilization of secondary nucleus but it is absent in some of the seeds viz. pea, bean, phaseolus (moong) etc. It is due to lack of 

  1. Certain enzymes

  2. Dicotyledonous hormone

  3. Growth hormone

  4. None of the above


Correct Option: D
Explanation:

In almost all angiosperms, double fertilisation takes place where a triploid endosperm is formed. In a few cases, it is non - endospermous where the entire endosperm is consumed during the development of embryo.

Endosperm of angiosperms results after fertilization from ................

  1. Antipodal cells

  2. Zygote

  3. Synergids

  4. Secondary nucleus


Correct Option: D
Explanation:

Endosperm of angiosperm results when the secondary nuclei which is diploid fuses with the second sperm entering the apparatus, which is haploid in nature.

The plant, whose seeds are known to have longest viability period is

  1. Nelumbo nucifera 

  2. Triticum vulgare 

  3. Zizyphus jujube 

  4. Carica papaya 


Correct Option: A
Explanation:

Water lotus (Nelumbo  nucifera) have an unusually long period of viable germination. Even if, a seed is in the ideal condition of germination, it might remain dormant for decades. They show self-preservation and resistance to germination. 

So, the correct answer is 'Nelumbo nucifera'

Fruit is 

  1. Ripened ovule

  2. Ripened bud

  3. Ripened ovary

  4. Ripened pistil


Correct Option: C
Explanation:

The ovary is converted into fruit after the formation of an embryo and protects the seed in angiosperms.

So, the correct option is 'Ripened ovary'

After fertilization ovary changes into

  1. Seed

  2. Flower

  3. Fruit

  4. None of the above


Correct Option: C
Explanation:
After the embryo formation, the female part and the ovule starts converting to protect the seed and ovary is the part which converts into fruit in which seed is kept in angiosperms.
So the correct option is 'Fruit'