Tag: biology

Questions Related to biology

Nasal chamber is divided into two parts by ____________

biology neural control and coordination human nose nose nose : the olfactory organ

  1. $Sphenoid$

  2. $Palatine$

  3. $Mesethmoid$

  4. $Zygomatic$

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Correct Option: A

What part is developed into a seed?

types of endosperms plant kingdom biology

  1. Endosperm

  2. Cotyledons

  3. Synergids

  4. Hypocity

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Correct Option: A

The dry (mass excluding water) of a seed in the process of germination

types of endosperms plant kingdom biology

  1. Increase over time until the first leaves appear

  2. Decreases over time until the first leaves appear

  3. Stays constant until the first leaves appear

  4. First Increases and then decreases until the first leaves appear

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Correct Option: A
Explanation:

During the germination process, there is a permanent increase of cell size and dry mass of the seed and water uptake may differ from day to day, plant take more water on a wet day and less on a dry day.

So the correct option is 'Increase over time until the first leaves appear.'

If the leaf tip cells posses 14 chromosomes that how many chromosomes will be present in the endosperm of Pisum satium?

types of endosperms plant kingdom biology

  1. 7

  2. 14

  3. 21

  4. 28

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Correct Option: C
Explanation:

Leaves of a plant are diploid as it forms from zygote which is diploid itself.

The gametes are haploid means contain 7 chromosomes.
Endosperm is triploid means it has 21 chromosomes.
Gamete n=7
Leaf 2n=14
Endosperm 3n=21
So the correct option is '21'.

At which stage one can distinguish between nuclear and cellular type of endosperm?

types of endosperms plant kingdom biology

  1. Stage following division of primary endosperm nucleus

  2. Mature stage of endosperm

  3. When embryo has started divisions

  4. At heart shaped stage of embryo

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Correct Option: A
Explanation:
In the nuclear type of endosperm, the first division of the primary endosperm nucleus and few subsequent nuclear divisions are not accompanied by wall formation. The nuclei produced are free in the cytoplasm of the embryo sac and they may remain free indefinitely or wall formation takes place later.
In the cellular type of endosperm, there is cytokinesis after each nuclear division of the endosperm nucleus. The endosperm, thus, has a cellular form, from the very beginning because first and subsequent divisions are all accompanied by wall formation.
So, the correct option is 'Stage following division of primary endosperm nucleus'.

(a) Endosperm development in most of the plants is nuclear type
(b) In rice, endosperm is starchy and present in mature seed.

types of endosperms plant kingdom biology

  1. Both (a) and (b) are correct

  2. Only (a) is correct

  3. Only (b) is correct

  4. Both (a) and (b) are incorrect

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Correct Option: A
Explanation:

(a) Endosperm is the layer of tissue in the seeds that surround the embryo and provides nutrition' It is mainly of three different types:

  1. Nuclear endosperm is formed by the free nuclear division and cell wall formation does not occur. It is the most common type of endosperm in most of the plants.
  2. Cellular endosperm cell wall formation occurs at the same time when a nuclear division occurs.
  3. Helobial endosperm is the intermediate of both nuclear and cellular endosperm. It is the least common type of endosperm.

(b) In rice during the time of processing, all the things including rice bran are removed, this leaves the only endosperm which is found to be white and starchy. It is present in the seeds of the plants.

So, the correct option is 'Both Endosperm development in most of the plants is the nuclear type and In rice, the endosperm is starchy and present in the mature seed'.
So the correct answer is option A

In Angiosperms, the endosperm is

types of endosperms plant kingdom biology

  1. Diploid protective tissue

  2. Haploid nutritive tissue

  3. Triploid nutritive tissue

  4. Tetraploid protective tissue

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Correct Option: C
Explanation:

Because it is formed by separate fertilization, the endosperm constitutes an organism separate from the growing embryo. About 70% of angiosperm species have endosperm cells that are polyploid. These are typically triploid (containing three sets of chromosomes). So, the correct option is C. ( Triploid nutritive tissue )

Coconut water is _______ part of endosperm.

types of endosperms plant kingdom biology

  1. Cellular

  2. Free nuclear

  3. Cellular as well as nuclear

  4. Neither cellular nor free nuclear

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Correct Option: A

Scutelum represent the:

types of endosperms plant kingdom biology

  1. Endosperm

  2. Cotyledons

  3. Radicle

  4. Plumule

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Correct Option: A

The plant is called helobial, when there is a type of endosperm development which is intermediate between the nuclear and the cellular types.

types of endosperms plant kingdom biology

  1. $Linnophyton$

  2. $Vallisneria$

  3. $Eremurus$

  4. All of the above

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Correct Option: D
Explanation:

Helobial endosperm is an intermediate between nuclear and cellular types. Helobial endosperm formation is a type of endosperm formation, where a cell wall is laid down between the first two nuclei, after which one half develops endosperm along the cellular pattern and the other half along the nuclear pattern.