Tag: gymnosperms

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Questions Related to gymnosperms

Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

Occurrence of triploid primary endosperm nucleus is characteristic of.

  1. Algae

  2. Bryophytes

  3. Gymnosperms

  4. Angiosperms
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The primary endosperm nucleus is formed by the fusion of two polar nuclei and one male gamete, resulting in a triploid (3n) state, which is unique to angiosperms.

Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

In angiosperms the number of meiotic divisions required to produce $100$ macrospores is?

  1. $125$
  2. $100$
  3. $50$
  4. $25$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Each meiotic division of a megaspore mother cell produces 4 megaspores. To produce 100 functional megaspores (assuming one per division), you need 100 meiotic divisions.

Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

External water is not required for fertilization of

  1. Pteriodophytes

  2. Bryophytes

  3. Thallophytes

  4. Spermatophytes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Spermatophytes (seed plants, including gymnosperms and angiosperms) do not require external water for fertilization because they use pollen tubes to deliver sperm to the egg.

Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

Select the correct statements from the following.
I. Endosperm is generally triploid in angiosperms.
II. All angiosperms have monosporic and endosporic embryo sac.
III. Angiosperms are characterised by double fertilization.
IV. All angiosperms show indirect pollination and siphonogamy.

  1. I, II and IV

  2. II, III and IV

  3. I, III and IV

  4. I, II, III and IV
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

I, III, and IV are correct. II is incorrect because not all angiosperms have monosporic embryo sacs; some are bisporic or tetrasporic.

Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

Which of the following is false in angiosperms?

  1. Egg cell - haploid

  2. Megaspore - diploid

  3. Pollen grain - haploid

  4. Synergid - haploid

  5. Endosperm - triploid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Megaspores are haploid (n), produced by meiosis from the diploid megaspore mother cell. The option stating they are diploid is false.

Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

Datura is a classical example of study of

  1. Monosomics

  2. Trisomics

  3. Triploids

  4. Nullisomics
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Trisomics are those organisms, which have an extra chromosome (2n + 1). Trisomics were obtained for the first time in Datura stramonium (jimson weed) by A.F. Blakeslee and his co-workers. Since haploid chromosome number in this species is n = 12, 12 primary trisomics, 24 secondary trisomics and a large number of tertiary trisomics are possible. Most of the trisomics were identified by size, shape and other morphological features of the fruit.
So, the correct answer is 'Trisomics'.
Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

Which one of the following plants has ovary superior, monocarpellary and unilocular with several ovules on marginal placenta?

  1. Anona squamosa

  2. Datura stramonium

  3. Pisum sativum

  4. Ricinus comm unis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Anona squamosa (custard apple) belongs to the Annonaceae family, which features superior ovaries, monocarpellary conditions, and marginal placentation.

Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

Among angiosperm plants, the lowest chromosome & number is found in _________________.

  1. Haplopappus gracilis

  2. Crepis capillaris

  3. Arabidopsis thaliana

  4. Oenothera lamarckiana
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Haplopappus gracilis is well-known in botany for having one of the lowest chromosome numbers (2n = 4) among angiosperms.

Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

In angiosperms, the wall around the microspore tetrads is deposited with.

  1. Callose

  2. Cellulose

  3. Pectocellu lose

  4. Sporopollenin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During microsporogenesis, the microspore mother cells are surrounded by a callose wall, which is later degraded by the enzyme callase to release the microspores.

Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

In angiosperms, the egg is?

  1. Completely surrounded by a wall

  2. Surrounded by a wall only at the micropylar end

  3. Surrounded by a wall only at the chalazae end

  4. Devoid of wall
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In angiosperms, the egg cell within the embryo sac is a distinct cell enclosed by a plasma membrane and a cell wall, unlike some primitive plants where gametes might be naked.