Name: Apomixis and Polyembryony
Uploaded: 2019-07-19
Duration: 7 min 23 s
Description: Apomixis and polyembryony are unusual forms of reproduction that allow seed formation, for continuity of life, without genetic shuffling. Do you want to know...

Question

What is sexual reproduction? Describe the isogamous, anisogamous and oogamous types of sexual reproduction giving examples.

Accepted Answer

The process by which reproduction takes place by the union of unicellular units called gametes is termed sexual reproduction. Sexual reproduction in plants is mainly of two types: Syngamy and conjugation.
Syngamy: The method of sexual reproduction is called syngamy when two cells of opposite sexes fuse permanently.

In this case, one male gamete unites with the egg within the embryo sac forming a diploid zygote (2n). This process is also called generative fertilization.

Syngamy are of three types, such as

Isogamy: In isogamy, fusion takes place between two identical gametes (isogametes) to produce a zygote (zygospore) e.g., Ulothrix.

Anisogamy-In anisogamy union of dissimilar gametes (heterogametes) takes place to yield zygote (oospore) e.g., Volvox. Of the two heterogametes, the male gamete is called sperm or antherozoid which is smaller but active and the female gamete is known as ovum or egg which is larger but passive.

Oogamy: In oogamy one of the gametes is small flagellate and motile while the other one is large non-flagellate and non-motile unite with each other to form a zygote. The motile flagellate gamete is the male gamete and is called an antherozoid or spermatozoid. The non-motile larger female gamete is called egg or ovum or oosphere.

What is sexual reproduction? Describe the isogamous, anisogamous and oogamous types of sexual reproduction giving examples.

Important Questions on Sexual Reproduction in Flowering Plants

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