Question 1

Which hormone is produced by the implanted embryo and is responsible for maintaining the corpus luteum during the first trimester of pregnancy?

Accepted Answer

Human chorionic gonadotropin (hCG)

Question 2

During fertilization, what prevents polyspermy after the first sperm successfully fuses with the oocyte?

Accepted Answer

Depolarization of the oocyte membrane and release of chemicals

Question 3

Which fetal circulatory structure allows blood to bypass the lungs by connecting the pulmonary trunk to the aorta?

Accepted Answer

Ductus arteriosus

Question 4

A woman stops taking her birth control pills, which contain constant levels of estrogen and progestin. What physiological event is most likely to occur as a result?

Accepted Answer

Endometrium sloughs off, resulting in menstrual bleeding

Question 5

Which embryonic germ layer gives rise to the nervous system and skin?

Accepted Answer

Ectoderm

Question 6

A newborn exhibits jaundice due to elevated bilirubin levels. Which physiological process is most likely responsible?

Accepted Answer

Immature liver processing bilirubin slowly

Question 7

Which of the following best describes the process of capacitation in sperm?

Accepted Answer

Sperm membranes become fragile, allowing acrosomal enzymes to be released

Question 8

A couple both carry the defective gene for cystic fibrosis. What is the probability that their child will have the disease?

Accepted Answer

$$\frac{1}{4}$$

Question 9

Which event marks the transition from embryo to fetus during human development?

Accepted Answer

Beginning of the ninth week after fertilization

Question 10

Which congenital defect is most commonly prevented by maternal intake of folic acid during pregnancy?

Accepted Answer

Neural tube defects (NTDs)

Question 11

Which of the following best explains why sex-linked diseases are more commonly expressed in males?

Accepted Answer

Males have only one X chromosome, so defects are not masked by another X

Question 12

During gastrulation, which structure forms as a groove in the embryonic disc and is essential for cell migration?

Accepted Answer

Primitive streak

Question 13

Which process during meiosis increases genetic diversity by exchanging chromosomal parts between homologous chromosomes?

Accepted Answer

Recombination (cross-over)

Question 14

A fetus is diagnosed with Down's syndrome. Which chromosomal abnormality is present?

Accepted Answer

Trisomy of chromosome 21

Question 15

Which hormone is responsible for the milk let-down reflex during lactation?

Accepted Answer

Oxytocin

Question 16

Which fetal structure allows mixing of blood between the left and right sides of the heart?

Accepted Answer

Foramen ovale

Question 17

A newborn is delivered in breech position. Which intervention is most likely required?

Accepted Answer

Cesarean section

Question 18

Which term describes the rapid cell divisions without an increase in cell size that occur after fertilization?

Accepted Answer

Cleavage

Question 19

Which genetic inheritance pattern involves more than one gene contributing to a single trait, such as skin color?

Accepted Answer

Polygene inheritance

Question 20

A pregnant woman is exposed to thalidomide during the limb bud stage. What is the most likely outcome for the fetus?

Accepted Answer

Flipper-like limb defects

Chapter 27: Development and Heredity – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards