What is the change in the amount of yolk in the eggs in the process of vertebrate phylogenesis

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MEDICAL BIOLOGY
Md shihab shahriar.
Practical class no 7

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Ques:What is the change in the amount of yolk in
the eggs in the process of vertebrate
phylogenesis?
• the change in the amount of yolk in the eggs in the process of vertebrate phylogenesis will be
fertilization.
The phylogeny of a group, in this case back-boned animals (vertebrates), represents the course of
evolutionary change undergone by that group over time. It is typically represented in the form of
a dichotomous branching tree in which the vertical axis represents time and the horizontal axis
represents closeness of relationship . Fertilization is the fusion of gametes to give rise to a new
individual organism or offspring and initiate its development. This cycle of fertilisation and
development of new individuals is called sexual reproduction. During double
fertilisation in angiosperms the haploid male gamete combines with two haploid polar nuclei to
form a triploid primary endosperm nucleus by the process of vegetative fertilisation.
Fertilization occurs when a sperm and an egg have fused together to form a zygote, which begins
to divide as it moves towards the uterus.
of paternal origin, with an egg nucleus, of maternal origin, to form the primary nucleus of
an embryo. In all organisms the essence of fertilization is, in fact, the fusion of
the hereditary material of two different sex cells, or gametes, each of which carries half the
number of chromosomes typical of the species. The most primitive form of fertilization, found in
microorganisms and protozoans, consists of an exchange of genetic material between two cells.