Answer the following questions.
List the characteristic features of gymnosperms and angiosperms.
Answers
Answer:
Angiosperms -1)Seed -producing flowering plants whose seeds are enclosed within an ovary . 2)Lifecycle is seasonal . 3)Present in flowers, can be unisexual or bisexual. Gymnosperms - 1)Seeds producing non - flowering plants whose seeds are unenclosed
Answer:
Characteristics of Gymnosperms
Following are the important characteristics of gymnosperms:
They do not produce flowers.
Seeds are not formed inside a fruit. They are naked.
They are found in colder regions where snowfall occurs.
They develop needle-like leaves.
They are perennial or woody, forming trees or bushes.
They are not differentiated into ovary, style and stigma.
Since stigma is absent, they are pollinated directly by the wind.
The male gametophytes produce two gametes, but only one of them is functional.
They form cones with reproductive structures.
The seeds contain endosperm that stores food for the growth and development of the plant.
These plants have vascular tissues which help in the transportation of nutrients and water.
Xylem does not have vessels and the phloem has no companion cells and sieve tubes.
Characteristics of Angiosperms
Angiosperms have diverse characteristics. The important characteristics of angiosperms are mentioned below:
All plants have flowers at some stage in their life. The flowers are the reproductive organs for the plant, providing them with a means of exchanging genetic information.
The sporophyte is differentiated into stems, roots, and leaves.
The vascular system has true vessels in the xylem and companion cells in the phloem.
The stamens (microsporophyll) and the carpels (megasporophyll) are organized into a structure called the flower.
Each microsporophyll has four microsporangia.
The ovules are enclosed in the ovary at the base of the megasporophyll.
Angiosperms are heterosporous, i.e., produce two kinds of spores, microspore (pollen grains) and megaspores.
A single functional megaspore is permanently retained within the nucellus.
The pollen grains transfer from the anther to stigma and reproduction takes place by pollination. They are responsible for the transfer of genetic information from one flower to the other. The pollen grains are much smaller than the gametophytes or reproductive cells present in the non-flowering plants.
The sporophytes are diploid.
The root system is very complex and consists of cortex, xylem, phloem, and epidermis.
The flowers undergo double and triple fusion which leads to the formation of a diploid zygote and triploid endosperm.
Angiosperms can survive in a variety of habitats, including marine habitats.
The process of fertilization is quicker in angiosperms. The seeds are also produced quickly due to the smaller female reproductive parts.
All angiosperms are comprised of stamens which are the reproductive structures of the flowers. They produce the pollen grains that carry the hereditary information.
The carpels enclose developing seeds that may turn into a fruit.
The production of the endosperm is one of the greatest advantages of angiosperms. The endosperm is formed after fertilization and is a source of food for the developing seed and seedling.