explain the different kinds of syngamy 5mark from 12th
Answers
Answer:
An important characteristic of angiosperms is double fertilization, where two nuclei (of sperm) from each of the pollen tubes go on to fertilise two other cells that belong to the ovary. A diploid zygote is formed when one of the sperm cells fertilizes one of the egg cells. An embryo now develops from this diploid zygote. The fusion of the cells in such a scenario is called syngamy. It can be noted that syngamy is also referred to as true fusion and generative fertilisation.
Explanation:
Types of syngamy
Syngamy is of two kinds on the basis of the source of fusion gametes, which are
Self-fertilization or Endogamy: The includes the fusion of two forms of gametes originating from the same parent for example, Taenia. It is a process is very uncommon.
Cross-fertilization or Exogamy: When two fusing gametes for example in human, frog, cockroach, etc. are derived from separate parents. It is more general.
There are three types of syngamy and they are:
Isogamy: This occurs when the gametes that fuse are similar. An advanced system of recognition is used so as to avoid self-fertilization. Surface proteins such as cells of immune system help in recognizing the different types of genotypes.
Heterogamy: This happens when the gametes are of two different sizes. Based on the division of labor, the difference between the two gametes are done. Usually the female is larger while the male is smaller. Also, the number of male gametes is more so that there is an increase in the competition and makes fertilization likely.
Oogamy: This takes place when the mobility of the gametes are different. Oocyte is the non-motile female and spermatozoon is the flagellate male. In most of the cases, spermatozoon is the only mobile gamete. Spermatozoa and spermatia are known as sperms.
Answer:
Syngamy means the fusion of two haploid gametes to produce a diploid zygote.
There are three types of syngamy:
- Isogamy
- IsogamyHeterogamy
- Oogamy
The distinction between the three different types of syngamy is:
1. Isogamy - The word 'Iso' means similiar. Therefore, isogamy is the fusion of two morphologygically and physiologically similar gametes. Isogamy is found in most unicellular eukaryotes.
2. Heterogamy - The word 'Hetero' means different. Therefore, heterogamy is the fusion of two morphologygically and physiologically different gametes, which are called the male and the female gamete.
3. Oogamy - Oogamy is an extreme type of syngamy where the gametes differ in both size, form and even motility. In oogamy the large female gamete is immobile, while the small male gamete is mobile, which moves towards the female gamete to fuse with it i.e. primates, humans.
To support the above answer refer to the following link,
https://brainly.in/question/12331942
To support the above answer refer to the following link,
https://brainly.in/question/40775107