Tag: biology

Questions Related to biology

Cellular endosperm can be seen in ........................

types of endosperms plant kingdom biology

  1. Family Annonaceae

  2. Gentianaceae

  3. Adoxa Peperomia

  4. All of the above

Show answer
Correct Option: D
Explanation:

Cellular endosperm formation - where a cell wall formation is coincident with nuclear divisions. Coconut meat is cellular endosperm. Acoraceae has cellular endosperm development while other monocots are helobial. Examples are: Gentianaceae, Adoxa and Peperomia.

Ruminate endosperm occurs in 

types of endosperms plant kingdom biology

  1. Cruciferae

  2. Euphorbiaceae

  3. Asteraceae

  4. Annonaceae

Show answer
Correct Option: D
Explanation:
Ruminate endosperm is the condition in which the endosperm is dissected by in-growths of the seed coat, is a common condition in the palms or Annonaceae. This type of  endosperm develops early and hence the in-growths are formed directly into its tissue.
Seeds of Annonaceae are characterized as possessing are one to many pistil; have a fleshy and usually brightly colored cover, have ruminate endosperm (nutritive tissue surrounding the embryo) and are oily.
hence, answer is 'Annonaceae'.

Free nuclear divisions in the life cycle of angiosperms can be traced in .........

types of endosperms plant kingdom biology

  1. Cellular endosperm

  2. Nuclear endosperm

  3. Helobial endosperm

  4. Both (B) and (C)

Show answer
Correct Option: D
Explanation:

Nuclear endosperm formation - where repeated free nuclear divisions take place; if a cell wall is formed, it will form after free nuclear divisions. Commonly, referred to as liquid endosperm. Coconut juice is an example of this.
Helobial 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.

In a nuclear endosperm, which of the following is seen? 

types of endosperms plant kingdom biology

  1. Every nuclear division is followed by wall formation.

  2. Initially free-nuclear divisions followed by wall formation.

  3. First division followed by wall formation and other free nuclear.

  4. None of the above.

Show answer
Correct Option: B
Explanation:

The three principal types of endosperm formation found in angiosperms—nuclear, cellular and helobial and are classified on the basis of when the cell wall forms. In nuclear endosperm formation, repeated free-nuclear divisions take place; if a cell wall is formed, it will form after free-nuclear division. In cellular endosperm formation, cell-wall formation is coincident with nuclear divisions. In helobial endosperm formation, 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. 

Thus, the correct answer is option B.

Assertion : Nuclear endosperm is formed by subsequent nuclear divisions with or without wall formation.

Reason : Coconut is an example of such endosperm, where the endosperm remains nuclear throughout the development of the fruit.

types of endosperms plant kingdom biology

  1. Both assertion and reason are true and reason is a correct explanation of the assertion.

  2. Both assertion and reason are true but reason is not a correct explanation of the assertion.

  3. Assertion is true but Reason is false

  4. Both Assertion and Reason are false

  5. Assertion is false but Reason is true

Show answer
Correct Option: B
Explanation:
In free nuclear or nuclear type of endosperm the PEN undergoes multiple divisions with no or partially formed cell walls at a later stage of division.
This type of endosperm formation is observed in coconut, where the liquid or the coconut water is the free nuclear stage while the white layer formation is development of the cell wall
So, the correct answer is 'Both assertion and reason are true but reason is not a correct explanation of the assertion'

Which one of the following phytochromones is associated with seed maturation?

types of endosperms plant kingdom biology

  1. ABA

  2. Kinetin

  3. Ethylene

  4. IAA

Show answer
Correct Option: A

Mango trees do not and cannot grow in temperate regions. The most important environment factor responsible for it. 

types of endosperms plant kingdom biology

  1. soil

  2. temperature

  3. water

  4. light

Show answer
Correct Option: B
Explanation:

Temperature has a direct effect on working of enzymes. Through enzymes, it influences basal metabolite, activity and physiological functions of the organism Hence, mango trees cannot grow in temperate countries like canada and Germany. 

Ruminate endosperm occurs in the seeds of.

types of endosperms plant kingdom biology

  1. Arecaceae

  2. Poaceae

  3. Myrtaceae

  4. Euphorbiaceous

Show answer
Correct Option: A

The coconut water from tender coconut represents

types of endosperms plant kingdom biology

  1. Free nuclear endosperm

  2. Free nuclear proembryo

  3. Fleshy mesocarp

  4. Endocarp

Show answer
Correct Option: A
Explanation:
The coconut water from tender coconut represents the free nuclear or liquid endosperm. During the development of nuclear type of endosperm, the primary endosperm mother cell divides by free nuclear divisions, and these divisions are not followed by cell wall formation. Thus, the free nuclei remain in the cytoplasm of the embryo sac.
So, the correct answer is A.

In Angiosperms, endosperm is formed by

types of endosperms plant kingdom biology

  1. Free nuclear division of megasphore

  2. Division of fused polar endosperm nuclei

  3. Division of fused secondary nucleus and male gamete

  4. Division of fused synergids and male gamete

Show answer
Correct Option: C
Explanation:

The endosperm is a tissue produced inside the seeds of most of the flowering plants following fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. It is formed by the fusion of secondary nucleus and one of the male gamete.

So the correct answer should be option "division of secondary nucleus and male gamete".