Animal Development

Which of these regions is most likely to develop into the Drosophilia's head?A. AB. BC. CD. DE. E

Disruption of the gradient of an inducer (i.e., an inductive signal) during an animal's development would NOT be expected to result ina. altered pattern formation.b. altered development along one of the body axes.c. increased numbers of mutation in the animal's DNA.d. abnormal gene regulation in some of the animal's cells.e. missing body parts.

The following quote is describing a yellow-pigmented region of the egg of marine invertebrate. “An orange or yellow colored cytoplasm, initially uniformly distributed in egg, becomes localized to a crescent when the cortex rearranges right after fertilization. Cells that obtain the pigmented material become muscle, as indicated by the fate map of this embryo.” Which of the following best describes the content of this area?a. cytoplasmic determinant b. Hox gene c. Hormone d. endoderm e. blastopore

If an important cytoplasmic determinant were missing from an animal zygote, what would you expect to happen as the zygote developed into a multicellular organism?a. The animal would lack certain amino acids.b. The animal would lack ribosomes.c. DNA polymerase would be unable to replicate the animal's genome.d. The animal would develop normally. e. One of the animal's major body axes would fail to develop normally.

Identical twins result from a single fertilization to form a zygote, which then clones itself.a. Trueb. False

Fraternal (nonidentical) twins result from two simultaneous fertilizations, which form two separate zygotes. a. Trueb. False

The process that merges the gametes from two parents is: a. Fertilizationb. Meiosisc. Mitosisd. Conjugation

A zygote is: a. A haploid cellb. A gametec. A product of meiosisd. All are correcte. A diploid cell

A __________ is a hollow ball of cells of an early animal embryo.a. coelomb. gastrulac. blastulad. blastoporee. inner cell mass

During the formation of an embryo, a hollow sphere of cells with a fluid-filled cavity inside is termed a _____.A. blastulaB. gastrulaC. morulaD. blastocoelE. neurula

The human blastocystA. has three germ layers.B. contains a fluid-filled central cavity.C. is the expanded end of the gastrula.D. is the fertilized egg.E. gives rise to umbilical blood vessels.