Question 1

Which of the following best describes the difference between direct and indirect development in animals?

Accepted Answer

Direct development produces offspring that resemble the adult, while indirect development involves a larval stage that looks very different from the adult.

Question 2

During animal development, which process is responsible for the formation of the three primary tissue layers?

Accepted Answer

Gastrulation

Question 3

Which extraembryonic membrane is primarily responsible for gas exchange in the amniotic egg of reptiles and birds?

Accepted Answer

Chorion

Question 4

A scientist transplants cells from a region of a light-colored amphibian blastula that normally becomes skin into a region of a dark-colored blastula that normally becomes nerve tissue. The transplanted cells develop into nerve tissue. What does this experiment demonstrate?

Accepted Answer

Cell fate is determined by the location and chemical signals from neighboring cells (induction).

Question 5

Which tissue layer gives rise to the nervous system during animal development?

Accepted Answer

Ectoderm

Question 6

Which of the following is a function of homeobox (Hox) genes in animal development?

Accepted Answer

They regulate the development of specific body regions by encoding transcription factors.

Question 7

In mammals, what is the primary function of the placenta?

Accepted Answer

To exchange nutrients, gases, and wastes between mother and embryo without mixing their blood supplies

Question 8

Which hormone is responsible for stimulating uterine contractions during labor and also plays a role in milk ejection during lactation?

Accepted Answer

Oxytocin

Question 9

A mutation in a fruit fly homeobox gene causes the development of an extra pair of wings. What does this reveal about the function of homeobox genes?

Accepted Answer

They control the development and identity of body segments.

Question 10

Which of the following best explains why all cells in an animal’s body (except gametes) are genetically identical but have different structures and functions?

Accepted Answer

Different cells express different sets of genes due to regulation by transcription factors.

Question 11

Which of the following is a correct sequence of early embryonic development in animals?

Accepted Answer

Zygote → Morula → Blastula → Gastrula

Question 12

Which of the following is a real-world example of indirect development?

Accepted Answer

A caterpillar transforming into a butterfly through metamorphosis

Question 13

Which of the following statements about aging is supported by current scientific evidence?

Accepted Answer

Aging is associated with the gradual accumulation of damage to biological molecules, especially DNA.

Question 14

Which of the following best describes the role of apoptosis during organogenesis?

Accepted Answer

It prunes away excess cells to sculpt functional organs and structures.

Question 15

Which of the following is a function of the yolk sac in amniotic eggs?

Accepted Answer

It provides nourishment to the developing embryo.

Question 16

Which of the following best explains why naked mole rats are of interest to aging research?

Accepted Answer

They exhibit negligible senescence, have efficient DNA repair, and are resistant to cancer.

Question 17

Which of the following best describes the positive feedback mechanism during human labor?

Accepted Answer

Uterine contractions cause the release of oxytocin, which increases contractions, leading to more oxytocin release.

Question 18

Which of the following is true about the transfer of substances across the placenta?

Accepted Answer

Small molecules like oxygen, nutrients, and some antibodies can cross, but large proteins and cells are restricted.

Question 19

Which hormone is primarily responsible for stimulating milk production after childbirth?

Accepted Answer

Prolactin

Question 20

Which of the following best describes the role of maternal molecules in early embryonic development?

Accepted Answer

They are localized in the egg cytoplasm and help direct early cell differentiation by regulating gene expression.

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