Explain what happens to the zona pellucida after the egg is fertilised

Biology

2 answers:

vodka [1.7K]2 years ago

8 0

write it in your own words:

"In humans, five days after the fertilization, the blastocyst performs zona hatching; the zona pellucida degenerates and decomposes, to be replaced by the underlying layer of trophoblastic cells. The zona pellucida is essential for oocyte growth and fertilization."

The zona pellucida supports communication between oocytes and follicle cells during oogenesis; protects oocytes, eggs, and embryos during development, and regulates interactions between ovulated eggs and free-swimming sperm during and following fertilization.

Lesechka [4]2 years ago

5 0

The blastocyst achieves zona hatching. The zona pellucida deteriorates and disintegrates, waiting for its replacement by the underlying layer of trophoblastic cells.

Once a sperm enters the zona pellucida, it connects and combines with the plasma membrane of the oocyte. Union occurs at the back region of the sperm head. The molecular characteristics of sperm-oocyte binding are not entirely resolved.

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kvasek [131]

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8 0

3 years ago

Suppose "A" is a dominant gene for the ability to taste phenylthiocarbamide and "a" is a recessive gene for the inability to tas

dexar [7]

Complete question:

Suppose "A" is a dominant gene for the ability to taste phenylthiocarbamide and "a" is a recessive gene for the inability to taste it. Which couples could possibly have both a child who tastes it and a child who does not?

a. father AA, mother aa

b. father Aa, mother AA

c. father Aa, mother Aa

d. father AA, mother AA

Answer:

c. father Aa, mother Aa

Explanation:

According to the given information, the ability to taste phenylthiocarbamide is a dominant trait and is imparted by the allele "A". This phenotype would be expressed in both homozygous and heterozygous conditions. The non-taster phenotype would be expressed in the homozygous recessive genotypes only.

To have both taster and non-taster children, both the parents should have at least one copy of the recessive allele. Among the given options, the father with genotype Aa and the mother with genotype Aa have the possibility to have both taster and non-taster children.

Aa x Aa= 3/4 taster (1/4 AA and 1/2 Aa): 1/4 non-taster (1/4 aa)