What is polyembryony in Fasciola hepatica?

2019-03-04 by No Comments

What is polyembryony in Fasciola hepatica?

Polyembryony is the phenomenon of two or more embryos developing from a single fertilized egg. Fasciola shows the phenomenon of polyembryony. Germ cells in the sporocyst and rediae are direct descendants of the zygote.

What is polyembryony and example?

Polyembryony, a condition in which two or more embryos develop from a single fertilized egg, forming what in humans is known as identical twins. A common phenomenon in many plant and animal species, polyembryony occurs regularly in the nine-banded armadillo, which usually gives birth to four identical young.

What is polyembryony explain it with at least one example?

When two or more than two embryos develop from a single fertilized egg, then this phenomenon is known as Polyembryony. In the case of humans, it results in forming two identical twins. The best example of Polyembryony in the animal kingdom is the nine-banded armadillo.

What is polyembryony give an example class 12?

Occurrence of more than one embryo in a seed is called polyembryony. It is due to formation of more than one egg in embryo sac formation of more embryosac synergid cell integument and nucellus cells may also develops into embryo. e.g.Orange lemon groundnut mango onion etc.

Is polyembryony a form of apomixis?

Apomixis is a type of asexual reproduction, whereas polyembryony is a type of sexual reproduction. In apomixis, the seeds are produced without the fusion of gametes (or fertilization) and polyembryony refers to the occurrence of many embryos in the same seed.

What disease does Fasciola hepatica cause?

Fascioliasis is a parasitic infection typically caused by Fasciola hepatica, which is also known as “the common liver fluke” or “the sheep liver fluke.” A related parasite, Fasciola gigantica, also can infect people.

What are the types of polyembryony?

The true polyembryony may be subdivided into two types: (i) Cleavage polyembryony, where the embryos arise within an embryo sac, either by a cleavage of the egg, or from the synergids, antipodals or endosperm; (ii) Adventive polyembryony, where the embryos arise from the tissues living outside the embryo sac, i.e., the …

What causes polyembryony?

The condition of the development of two or more embryos from one fertilised egg is called polyembryony. Polyembryony is common in citrus plants as well as mango and jamun where multiple embryos arise from sporophytic cells of ovules or zygote.

What are some examples of polyembryony?

What are some Examples of Polyembryony? Ans. Polyembryony is common in citrus plants as well as mango and jamun where multiple embryos arise from sporophytic cells of ovules or zygote.

Is polyembryony a type of apomixis?

Is Apple an example of polyembryony?

Polyembryony is also common in jamun (Syzygium cumini) and rose apple (Syzygium jambos). Number of embryos varies with species and varieties.

Does Onion show polyembryony?

Synergids and antipodal cells may also form embryos. Formation of extra embryos through sporophytic budding is called adventive polyembryony. Polyembryony is quite common in Onion, Groundnut, Mango, Lemon, Orange.

Where does polyembryony take place in the Fasciola?

Polyembryony is a special kind of reproduction involving a continuous line of germinal cells from the miracidium, through all the larval generation, to the gonads of the adult. This is known germinal lineage hypothesis. This view is widely accepted.

What is the definition of a false polyembryony?

False polyembryony :- This type includes the cases in which two or more embryos are formed as result of the development of the aposporic embryo sac. The cells of the nucellus or the integuments but generally they come to lie within the embryo sac.

Why do some plants have more than one type of polyembryony?

In plants, this phenomenon is caused either due to the fertilization of one or more than one embryonic sac or due to the origination of embryos outside of the embryonic sac. This natural phenomenon was first discovered in the year 1719 by Antonie van Leeuwenhoek in Citrus plant seeds.

Is there such a thing as accidental polyembryony?

Accidental or “sporadic” polyembryony in the form of monozygotic twinning occurs at a very low frequency in humans and in some other mammals under natural conditions, but the process can be augmented in vitro by embryo splitting technique ( Chan et al., 2000 ).