- An organism with extensive yolk, such as the chick,
A) has incompletecleavage. D)forms a blastoderm but no blastocoel.
B) has yolk evenly distributed in the egg. E) has completecleavage.
C) fails to synthesize DNA duringcleavage.
- Invagination
A) occurs in sea urchins.
B) forms the archenteron in echinoderms.
C) creates unique positions for new cell interactions.
D) requires unique cell movement.
E) All of the above
- When the blastopore dorsal lip is grafted from one frog embryoonto a second embryo, the second dorsal lip will
A) change the developmental fate of the surrounding cells.
B) change the polarity of the adjacent segments.
C) cause rapid cell division.
D) block gastrulation.
E) change the prospective potency of the surrounding cells.
- Gastrulation in birds differs in many ways from gastrulation infrogs. The main feature that both have in common is that
A) the neural tube forms.
B) somites are created.
C) cells from the surface of the blastocyst migrate to form thegut.
D) three germ layers are established.
E) All of the above
- In humans, the secondary oocyte forms:
- at ovulation.
- during telophase I.
- after fertilization.
- at birth.
- all of the above.
- In Ascaris:
- The secondary oocyte is fertilized.
- Two polar bodies are visible when the secondary oocyte is inprophase II.
- Both a haploid and a diploid nucleus are present in a primaryoocyte during early prophase I.
- Cell plates are formed during both anaphase I and anaphaseII.
- No correct answer is given.
- A gastrula is:
a. an embryo that is younger than a blastula.
b. a stage in development that has three tissue layers.
c. a type of egg that has yolk concentrated at one end of thecell.
d. an opening in the center of an early embryo.
e. something else
- A human cell containing 22 autosomes and one Y chromosome isa
a. somatic cell of amale b. zygote
c. somatic cell of afemale d. a sperm e. an ovum
- The spermatogonium is ________ , and the primary spermatocyteis __________ .
a. diploid,haploid b. haploid, diploid
c. haploid,haploid d. diploid,diploid e. triploid, diploid
- The first cavity formed in the rapidly dividing starfish embryois the:
a. Blastoderm. b. Archenteron.
c. Neural groove. d. Blastocoel. e. Trophoblast.
