Answer:
The correct answer would be zygote...blastocyst...embryo...fetus.
The fertilization of sperm and egg results in the formation of zygote. It receives genetic material from a male as well as a female parent.
It divides with the help of mitotic divisions and results in the formation of 2, 4, 8, and 16 celled stages.
It results in the formation of the hollow spherical ball of cells termed as a blastocyst. The cells are distributed to form the outer layer termed trophoblast and inner cell mass which gives rise to the embryo.
Trophoblast help in the implantation of the blastocyst into the uterine wall.
The cells of the embryo undergo organogenesis during different organs such as heart, brain, lungs et cetera are formed.
In humans, almost 9 weeks after the fertilization the developing embryo is considered a fetus.
The fetus development continues until birth.
The species was a keystone species.
Keystone species are the species that ''hold the ecosystem together''.
They have an important role in the trophic networks (food chains) and often they can even afflict changes in the abiotic part of the ecosystem (change the composition of soil, purify the water, lower the effect of the wind etc)
Therefore, when a keystone species is removed it affects greatly the whole ecosystem.
Answer:
it A
Explanation:
pick A hopefully it right
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