In a newly fertilized egg, the vitelline layer
A) opens the egg's nuclear membrane to allow haploid sperm DNA to enter.
B) hardens to form a protective cover.
C) secretes hormones that enhance steroidogenesis by the ovary.
D) reduces the loss of water from the egg and prevents desiccation.
E) provides most of the nutrients used by the zygote.
Answer: B
Learn More :
Biology
- During the early part of the cleavage stage in frog development, the rapidly developing cells
- As cleavage continues during frog development, the size of the blastomeres
- The pattern of embryonic development in which only the cells lacking yolk subsequently undergo cleavage is called
- Among these choices, the largest cell involved in frog reproduction is
- In a developing frog embryo, most of the yolk is
- At the moment of sperm penetration, human eggs
- A human blastomere is
- Compared to sea urchin eggs, those of mammals
- In mammalian eggs, the receptors for sperm are found in the
- Fertilization normally
- In mammals, the nuclei resulting from the union of the sperm and the egg are first truly diploid at the end of the
- In an egg cell treated with EDTA, a chemical that binds calcium and magnesium ions, the
- In sea urchins, the "fast block" and the longer lasting "slow block" to polyspermy, respectively, are
- The cortical reaction functions directly in the
- From earliest to latest, the overall sequence of early development proceeds in which of the following sequences?
- The vitelline layer of the sea urchin egg
- During fertilization, the acrosomal contents
- Contact of a sea urchin egg with signal molecules on sperm causes the egg to undergo a brief
- A reproductive difference between sea urchins and humans is
- A human zygote undergoes its first cell division
- A sea urchin zygote undergoes its first cell division
- The formation of the fertilization membrane requires an increase in the availability of
- Even in the absence of sperm, metabolic activity in an egg can be artificially activated by
- Contact of a sperm with signal molecules in the coat of an egg causes the sperm to undergo
If the answers is incorrect or not given, you can answer the above question in the comment box. If the answers is incorrect or not given, you can answer the above question in the comment box.