Question 1

Identical twins
A) are the result of a single fertilized egg
B) usually share an umbilical cord
C) usually share a placenta
D) both A and C

Accepted Answer

Identical twins are the result of a single fertilized egg that splits into two embryos. As such, they will share a placenta in the womb. However, not all identical twins share an umbilical cord. Sometimes each twin has their own individual umbilical cord, while other times they may share one cord or have separate cords that merge together.

Question 2

Which of the following is not formed by the mesoderm?
A) dermis of the skin
B) kidneys
C) bladder
D) muscles

Accepted Answer

The bladder is formed by the endoderm, not the mesoderm. The dermis of the skin, kidneys, and muscles are all formed by the mesoderm.

Question 3

The time from maximal cervical dilation until the baby exits through the vagina is the _____ stage of labor.
A) first
B) second
C) third
D) fourth

Accepted Answer

The second stage of labor is defined as the period of time from full dilation of the cervix to the birth of the baby.

Question 4

Which of the following is not a function of the placenta?
A) acting as the nutrient bridge between mother and baby
B) acting as an excretory organ
C) acting as an endocrine organ
D) All of the above are functions of the placenta.

Accepted Answer

All of the choices listed (A, B, and C) are functions of the placenta.

Question 5

Fertilization usually occurs in the
A) uterus
B) outer third of the oviduct near the ovary
C) inner third of the oviduct near the uterus
D) ovarian follicle

Accepted Answer

Fertilization typically occurs in the outer third of the oviduct, near the ovary. This is where the sperm and egg meet and combine to form a zygote. The fertilized egg then travels down the oviduct towards the uterus for implantation.

Question 6

The implantation of a fertilized egg outside the uterus is called
A) placenta previa
B) abruptio placentae
C) ectopic pregnancy
D) preeclampsia

Accepted Answer

The implantation of a fertilized egg outside the uterus is called an ectopic pregnancy. Placenta previa refers to the placenta attaching low in the uterus, abruptio placentae refers to the detachment of the placenta from the uterus, and preeclampsia refers to high blood pressure and organ damage in pregnant women.

Question 7

The time from the onset of uterine contractions to the complete dilation of the cervix is the _____ stage of labor.
A) first
B) second
C) third
D) fourth

Accepted Answer

The first stage of labor begins with the onset of uterine contractions and ends with full dilation of the cervix.

Question 8

Which of the following is not formed by the ectoderm?
A) dermis of the skin
B) epidermis of the skin
C) brain
D) spinal cord

Accepted Answer

The dermis of the skin is formed from the mesoderm, while the epidermis, brain, and spinal cord are derived from the ectoderm.

Question 9

Fraternal twins
A) are the result of two fertilized eggs
B) must be of the same sex
C) must have the same blood type
D) All of the above are true.

Accepted Answer

Fraternal twins are the result of two separate eggs being fertilized by two separate sperm. Therefore, they are not identical and can be of different sexes and may have different blood types.

Question 10

Because of the rapid cell division,the blastocyst is _____ as the fertilized egg.
A) about twice as large
B) about four times as large
C) almost eight times as large
D) the same size

Accepted Answer

The blastocyst is the same size as the fertilized egg because the zona pellucida restricts its growth, maintaining the overall size while the number of cells increases.

Question 11

Which of the following is not formed by the endoderm?
A) lining of the lungs
B) nasal bones
C) thymus gland
D) tonsils

Accepted Answer

The endoderm does not form bones, including the nasal bones which are formed from the mesoderm. The lining of the lungs (A), thymus gland (C), and tonsils (D) are all formed from the endoderm.

Question 12

Which of the following terms refers to a fertilized ovum?
A) blastocyst
B) embryo
C) zygote
D) morula

Accepted Answer

A zygote is a fertilized ovum, formed by the fusion of a sperm and an egg. The other terms refer to developing stages of the embryo after the formation of the zygote.

Question 13

Separation of the placenta from the uterine wall after 20 weeks' gestation is a condition called
A) placenta previa
B) abruptio placentae
C) ectopic pregnancy
D) preeclampsia

Accepted Answer

Separation of the placenta from the uterine wall after 20 weeks' gestation is known as abruptio placentae. Placenta previa refers to the placenta covering the cervix, ectopic pregnancy is implantation of the fertilized egg outside the uterus, and preeclampsia is a pregnancy-specific disorder characterized by high blood pressure and damage to organs.

Question 14

Which structure is a solid ball of cells that forms about 3 days after fertilization?
A) blastocyst
B) embryo
C) zygote
D) morula

Accepted Answer

The morula is a solid ball of cells that forms about 3 days after fertilization, before developing into a blastocyst. The zygote is the fertilized egg cell, and the embryo is the stage of development after the blastocyst has implanted in the uterus.

Question 15

The function of the yolk sac is to
A) provide food until the blastocyst implants in the uterus
B) develop into a protective structure called the "bag of waters"
C) help in the production of blood cells
D) All of the above are functions of the yolk sac.

Accepted Answer

The yolk sac helps in the production of blood cells in the early stages of embryonic development, before the fetal liver takes over this function. It does not provide food or develop into the "bag of waters".

Question 16

Blood type is an inherited trait; therefore
A) identical twins must have the same blood type
B) fraternal twins must have the same blood type
C) identical twins may have the same blood type,but don't have to
D) both A and B

Accepted Answer

Identical twins have the same genetic makeup, so they will have the same blood type. Fraternal twins, on the other hand, can inherit different blood types from their parents, just like any other siblings. Therefore, B is incorrect, and C and D are partially correct but do not provide the best choice.

Question 17

The sequence of development for the fertilized egg is
A) fertilization,zygote,morula,implantation,and blastocyst
B) fertilization,zygote,morula,blastocyst,and implantation
C) fertilization,zygote,blastocyst,morula,and implantation
D) fertilization,zygote,blastocyst,implantation,and morula

Accepted Answer

After fertilization, the zygote divides into a solid ball of cells called the morula. Next, the morula develops a fluid-filled cavity to form the blastocyst. Finally, the blastocyst travels down to the uterus to implant into the uterine wall.

Question 18

The process of the expulsion of the placenta occurs in the _____ stage of labor.
A) first
B) second
C) third
D) fourth

Accepted Answer

The expulsion of the placenta occurs in the third stage of labor, which typically lasts from a few minutes up to 30 minutes after the baby is born. During this stage, the uterus continues to contract, causing the placenta to detach from the uterine wall and be expelled through the birth canal. It is important for the entire placenta to be expelled to prevent bleeding and infection.

Question 19

Which structure is a hollow ball of cells that develops and implants into the uterus?
A) blastocyst
B) embryo
C) zygote
D) morula

Accepted Answer

The blastocyst is a hollow ball of cells that forms from the zygote (fertilized egg) during early embryonic development. This structure implants into the uterus and ultimately develops into the embryo. The morula is an earlier stage of embryonic development, and the zygote is the initial cell formed when sperm and egg unite. Therefore, the correct answer is A) blastocyst.

Question 20

If a blastocyst implants too close to the cervical opening,which of the following conditions can develop?
A) placenta previa
B) abruptio placentae
C) ectopic pregnancy
D) preeclampsia

Accepted Answer

If a blastocyst implants too close to the cervical opening, it can lead to placenta previa, which is a condition where the placenta implants low in the uterus and covers part or all of the cervix. This can cause complications during pregnancy, including bleeding and preterm labor. Abruptio placentae, ectopic pregnancy, and preeclampsia are not directly related to the location of the blastocyst implantation.

Quiz 24: Growth and Development

Identical twins

Which of the following is not formed by the mesoderm?

The time from maximal cervical dilation until the baby exits through the vagina is the _____ stage of labor.

Which of the following is not a function of the placenta?

Fertilization usually occurs in the

The implantation of a fertilized egg outside the uterus is called

The time from the onset of uterine contractions to the complete dilation of the cervix is the _____ stage of labor.

Which of the following is not formed by the ectoderm?

Fraternal twins

Because of the rapid cell division,the blastocyst is _____ as the fertilized egg.

Which of the following is not formed by the endoderm?

Which of the following terms refers to a fertilized ovum?

Separation of the placenta from the uterine wall after 20 weeks' gestation is a condition called

Which structure is a solid ball of cells that forms about 3 days after fertilization?

The function of the yolk sac is to

Blood type is an inherited trait; therefore

The sequence of development for the fertilized egg is

The process of the expulsion of the placenta occurs in the _____ stage of labor.

Which structure is a hollow ball of cells that develops and implants into the uterus?

If a blastocyst implants too close to the cervical opening,which of the following conditions can develop?