Tag: botany

Questions Related to botany

While studying a plant, you discover that it has chlorophyll, no xylem. Its multicellulcar sex organs are enclosed in a layer of jacket cells. Its gametophyte Stage is free living. The plant probability belongs to

botany kingdom plantae uses of bryophytes introduction to bryophytes cryptogams

  1. Chlorophyceae

  2. Bryophyte

  3. Pteridophyte

  4. Gymnosperm

Show answer
Correct Option: B
Explanation:

The life cycle of higher plants is dominated by the sporophyte stage, with the gametophyte borne on the sporophyte. In ferns, the gametophyte is free-living and very distinct in structure from the diploid sporophyte. Pteridophytes also have their multicellular sex organs covered in the multicellular jacket later.

So the correct answer should be option 'Pteridophyte' .

In which of the following groups would you place a plant which produces spores and embryos but lacks seeds and vascular tissues?

botany kingdom plantae uses of bryophytes introduction to bryophytes cryptogams

  1. Fungi

  2. Pteridophytes

  3. Bryophytes

  4. Gymnosperms

Show answer
Correct Option: C
Explanation:
1. The Plant body is a gametophyte. They grow in areas which arc in between the aquatic and terrestrial habitats i.e. amphibious zone and hence known as amphibious plants.
2. They have thalloid or leafy multi cellular green plant body.
3. The smallest form is microscopic (e.g. Zoopsis). The largest genus recorded so far is an Australian Dawsonia which is about 70 cms in length.
4. The dominant plant body is gametophyte (n) which is independent.
5. The plant body lacks true roots, stem or leaves.
6. Rhizoids - (root like structure) serve the function of roots.
7. The plants are green and possess chloroplasts.
8. They show autotrophic mode of nutrition.
9. Vascular tissues are completely absent.
10. Sexual reproduction is oogamous.
11. Sex organs are multi cellular and jacketed.
12. Male reproductive organ is known as antheridium. It is a club shaped structure being borne by a narrow stalk. It produces biflagellate and motile male gametes or antherozoids.
14. The female sex organ is known as archegonium. It is a flask shaped structure having a swollen base and a narrow neck.
15. Water is essential for fertilization.
16. The diploid zygote undergoes repeated divisions to form a multi cellular sporophyte.
17. Sporophyte is dependent on the gametophyte for nutrition.
18. Sporophyte generally consists of foot, seta and capsule. It produces haploid spores (homospores).
19. Spores on germination give rise to gametophyte plant.
20. Gametophyte and sporophyte differ in form which alternate with each other, thus heterologous alternation of generation is seen in Bryophytes.

Bryophytes are the first land plants but incompletely adapted to land conditions as______________________

botany kingdom plantae uses of bryophytes introduction to bryophytes cryptogams

  1. Plant body is parenchymatous

  2. Protonema is present

  3. Male gametes are motile

  4. Stomata are absent

Show answer
Correct Option: D
Explanation:

Certain features in bryophytes are not completely supporting the life of bryophytes on land like:

  • Absence of stomata
  • The plant body lacks true roots, stem or leaves
  • Vascular tissues are completely absent.
  • Water is essential for fertilization.

Bryophytes are dependent on water because

botany kingdom plantae uses of bryophytes introduction to bryophytes cryptogams

  1. Archegonium has to remain filled with water for fertilization.

  2. Water is essential for fertilization for homosporous nature.

  3. Water is essential for vegetative propagation.

  4. The sperms can easily reach up to the egg in the archegonium.

Show answer
Correct Option: D
Explanation:

Bryophytes require water to reproduce. The male gametes (sperm) require water to reach the female gamete. The fact that they are non-vascular plant only accounts for their small size and not why they are dependent on water.

Vascular and mechanical tissue is absent in_____________.

botany kingdom plantae uses of bryophytes introduction to bryophytes cryptogams

  1. Bryophyta

  2. Pteridophyta

  3. Gymnosperms

  4. Angiosperms

Show answer
Correct Option: A
Explanation:

Pteridophytes have a well-differentiated plant body with vascular tissues. Therefore, option B is incorrect. 
Gymnosperms have a well-differentiated plant body with vascular tissues. They produce naked seeds. Therefore, option C is incorrect. 
Angiosperms have a well-differentiated plant body with vascular tissues. They produce seeds enveloped in fruits. Therefore, option D is incorrect. 
Bryophytes have a well-differentiated plant body with stem and leaf-like structures. They do not have conducting or vascular tissues, i.e, xylem, and phloem. Thus, they are called non-vascular cryptogamic plants. They are very small in length usually 2 cm to 15 cm. So they do not need mechanical tissues.  Therefore, option A is correct.

Give the differences between thallophyta and bryophyta.

botany kingdom plantae uses of bryophytes introduction to bryophytes cryptogams

  1. Thallophyta: Body is thallus like, not differentiated into root, stem, and leaves.                                          Bryophyta: Plant's body is differentiated into leaf-like structure and rhizoids.

  2. Thallophyta: Sex organs single celled.
    Bryophyta: Sex organs multicellular.

  3. Both A and B

  4. None of these

Show answer
Correct Option: C
Explanation:

The differences between thallophyta and bryophyta are :
(i) Thallophyta: Body is thallus like, not differentiated into root, stem and leaves. Sex organs single celled. Example: Spirogyra.
(ii) Bryophyta: Plant body is differentiated into leaf and rhizoids. Sex organs multicellular. Example : Moss

Female sex organ of bryophytes is called as

botany kingdom plantae uses of bryophytes introduction to bryophytes cryptogams

  1. Ovary

  2. Oogonia

  3. Antheridium

  4. Archegonium

Show answer
Correct Option: D
Explanation:

Archegonium is the the female reproductive organ in ferns and mosses. An archegonium also occurs in some gymnosperms, e.g., cycads and conifers. It is a flask-shaped structure, consists of a neck, with one or more layers of cells, and a swollen base and the centre, which contains the egg. Neck-canal cells, located above the egg, disappear as the archegonium matures, thus producing a passage for entry of the sperm. The sperm are produced in the corresponding male reproductive organ, the antheridium.

Which does not occur in thallus of Marchantia?

botany kingdom plantae uses of bryophytes introduction to bryophytes cryptogams

  1. Nostoc

  2. Oil cells

  3. Starch grains

  4. Reticulate thickenings

Show answer
Correct Option: A

Sphaerocarpos belongs to

botany kingdom plantae uses of bryophytes introduction to bryophytes cryptogams

  1. Pteridophyta

  2. Bryophyta

  3. Gymnospermae

  4. Angiospermae

Show answer
Correct Option: B

More than one answer may be correct:
Marchantia polymorpha
1. Is dioecious
2. Possesses antheridiophores and archegoniophores
3. Lacks foot and seta in its sporophyte
4. Is heterosporous.

botany kingdom plantae uses of bryophytes introduction to bryophytes cryptogams

  1. 1, 2, 3 are correct

  2. 1 and 2 are correct

  3. 2 and 4 are correct

  4. 1 and 3 are correct

Show answer
Correct Option: B