During the early part of the cleavage stage in frog development, the rapidly developing cells

During the early part of the cleavage stage in frog development, the rapidly developing cells 

A) skip the mitosis phase of the cell cycle.
B) skip the S phase of the cell cycle.
C) skip the G1 and G2 phases of the cell cycle.
D) rapidly increase the volume and mass of the embryo.
E) skip the cytokinesis phase of the cell cycle.





Answer: C

As cleavage continues during frog development, the size of the blastomeres

As cleavage continues during frog development, the size of the blastomeres 

A) increases as the number of the blastomeres decreases.
B) increases as the number of the blastomeres increases.
C) decreases as the number of the blastomeres increases.
D) decreases as the number of the blastomeres decreases.
E) increases as the number of the blastomeres stays the same.






Answer: C

The pattern of embryonic development in which only the cells lacking yolk subsequently undergo cleavage is called

The pattern of embryonic development in which only the cells lacking yolk subsequently undergo cleavage is called 

A) arcadian development, which is typical of insects.
B) holoblastic development, which is typical of marsupial mammals.
C) meroblastic development, which is typical of humans.
D) holoblastic development, which is typical of amphibians.
E) meroblastic development, which is typical of birds.






Answer: E

Among these choices, the largest cell involved in frog reproduction is

Among these choices, the largest cell involved in frog reproduction is

A) the spermatozoon.
B) the ovum.
C) a blastomere in the vegetal pole.
D) a blastomere in the animal pole.
E) one of the products of the first cleavage.






Answer: B

In a developing frog embryo, most of the yolk is

In a developing frog embryo, most of the yolk is 

A) located near the animal pole.
B) located near the vegetal pole.
C) found within the cleavage furrow.
D) found within the blastocoels.
E) distributed equally throughout the embryo.







Answer: B

At the moment of sperm penetration, human eggs

At the moment of sperm penetration, human eggs 

A) have used flagellar propulsion to move from the ovary to the oviduct.
B) accept as many sperm as possible in order to select the one with the highest fertility.
C) are still located within the ovary.
D) have a paper-thin cell of calcium carbonate that prevents desiccation.
E) are still surrounded by follicular cells.






Answer: E

A human blastomere is

A human blastomere is 

A) an embryonic cell that is much smaller than the ovum.
B) an embryonic structure that includes a fluid-filled cavity.
C) that part of the acrosome that opens the egg's membrane.
D) a component of the zona pellucida.
E) a cell that contains a (degenerating) second polar body.





Answer: A