Tag: gymnosperms

Questions Related to gymnosperms

Ovules are naked in gymnosperm, because

  1. Fertilisation is absent

  2. True carpels are absent

  3. Archegonia are absent

  4. Endosperm is absent


Correct Option: B
Explanation:

The gymnosperms do not have petals or flowers, but they do produce seeds. The name 'Gymnosperm' means, 'naked seeds' and refers to the fact that the gymnosperms bears their seeds on the margins of modified leaves or cones. 

There are no sealed carpels, like those the define angiosperms. Although gymnosperms do have ovules, they do not have ovaries, pistils or stamens. Since the term 'fruit' refers to the mature ovary, gymnosperms do not in botanical usage have 'fruit' and the reproductive stages are referred to as cones.  

Gymnosperm plants do not produce fruits because they do not have

  1. Ovary

  2. Gametes

  3. Fertilization

  4. None of the above


Correct Option: A
Explanation:

In Gymnosperms the fertilized ovule does not develop into a fruit as it would in an angiosperm. Because gymnosperms have no ovary, they can never produce fruit. Seeds develop from the ovules that are found in the developed ovaries or fruit, but in the case of gymnosperms, the ovules are located directly on the surface of the flower or cone. Yews and ginkgoes develop fruit like structures, but their seed is not inside these organs, which makes them Gymnosperms.

Gymnosperm plants lack

  1. Vessels

  2. Fruits

  3. Companion cells

  4. All of the above


Correct Option: D
Explanation:

Gymnosperms are seed bearing non flowering plants. Since gymnosperms have no ovaries, they do not produce real fruits, at least not in the botanical sense. Because no fruit tissue surrounds gymnosperm seeds, the seeds are said to be "naked." 
In Gymnosperms vascular tissues are arranged into vascular bundles just like Angiosperms. However, xylem does not possess vessels and phloem is without companion cells, like pteridophytes.

Which plant group is exclusively perennial?

  1. Dicots

  2. Ferns

  3. Gymnosperms

  4. Monocots


Correct Option: C
Explanation:

A perennial plant or simply perennial is a plant that lives for more than two years. 

One of the main characteristics of gynmosperms is that the group consists of plants that are perennial and woody. 

Which group of plants is exclusively arborescent (woody)?

  1. Pteridophytes

  2. Dicots

  3. Gymnosperms

  4. Monocots


Correct Option: C
Explanation:

The gymnosperm is represented by a perennial, evergreen, woody plant. Most of them are trees and some are shrubs. A few gymnosperms may be lianas or climbers. There are no herbs. Gymnosperms include one of the world's tallest trees, Sequoia sempervirens.

Bitegmic ovules occur in which of the following gymnosperm plant?

  1. Ginkgo

  2. Taxus

  3. Gnetum

  4. All of the above


Correct Option: C
Explanation:

Megasporangium or ovule is borne on adaxial or upper surface of megasporophyll or ovuliferous scale and are generally orthotropous and unitegmic in gymnosperms but are bitegmic in the Gnetales.

Which of the following are absent in group gymnosperm?

  1. Trees

  2. Shrubs

  3. Liana

  4. Herbs


Correct Option: D
Explanation:

The gymnosperms are a group of seed-producing plants that do not produce flowers. These include conifers, cycads, Ginkgo, and gnetales. Though they are seed bearing their seeds are not enclosed in ovary they make up for about 700 species of woody plants with most of them being trees and some shrubs. A few gymnosperms however may lianas or climbers. However, there are no herbs in the group.

Fruits are not formed in gymnosperms, because

  1. Fertilization is absent

  2. Pollination is absent

  3. Seeds are not formed

  4. Ovary is absent


Correct Option: D
Explanation:

Fruits are not formed in gymnosperms due to absence of ovary. The ovules of a gymnosperm do not develop in an ovary but are "naked". Seeds develop from the ovules that are found in the developed ovaries but in the case of gymnosperms, the ovules are located directly on the surface of the flower or cone. 

The gymnosperm resembles with angiosperm in having

  1. Ciliated sperms

  2. Presence of ovary

  3. Presence of seed

  4. Presence of fruit


Correct Option: C
Explanation:

Gymnosperms and angiosperms are the phenerogames or spermatophytes. 

Phenerogams are the seed bearing plants. Gymnosperms are distinguished from angiosperms by having naked ovules and seeds. The ovules are not enclosed in an ovary and the seeds are not enclosed in a pericarp. 
In angiosperms or flowering plants, the seeds are enclosed in a fruit, and are known as "covered seeds".

Endosperm in gymnosperms is

  1. Haploid and developed after fertilization

  2. Haploid and developed before fertilization

  3. Triploid and developed before fertilization

  4. Triploid and developed after fertilization


Correct Option: B
Explanation:

Gymnosperms are the most primitive of the seed plants. A seed comprises two parts: an endosperm, which nourishes the embryo, and the embryo itself, which is fed by the endosperm.

In gymnosperms the endosperm grows from a spore (a cell with half the number of chromosomes n). Pollination may occur when the cone is small, but the endosperm continues to grow to completion before fertilisation occurs.