Question 1

In the last century global infant mortality rates have

Accepted Answer

Global infant mortality rates have decreased in the last century due to improvements in healthcare and public health initiatives.

Question 2

How long can a sperm survive in the female body?

Accepted Answer

Sperm can survive in the female body for up to 72 hours (3 days). This is why it is possible to get pregnant even if intercourse occurs a few days before ovulation.

Question 3

The fetal period lasts

Accepted Answer

The fetal period lasts from 9 weeks to birth, which is the period in which the fetus develops and matures. The other options are incorrect: A is the embryonic period, B is a partial range within the fetal period, and D is incorrect because it doesn't include the entire fetal period.

Question 4

Only about _________ fertilized eggs develop to maturity.

Accepted Answer

Only about 30% of fertilized eggs develop to maturity. Therefore, the best choice is C) 3 in 10.

Question 5

The mother's cells determine the gender of the baby.

Accepted Answer

The gender of a baby is determined by the father's sperm, which can carry either an X or a Y chromosome. If the sperm carrying an X fertilizes the egg, the baby will be female (XX); if the sperm carrying a Y fertilizes the egg, the baby will be male (XY). The mother's cells do not determine the gender of the baby.

Question 6

Which layer becomes the heart and circulatory systems?

Accepted Answer

The mesoderm layer is responsible for the development of the heart and circulatory systems. The ectoderm layer develops into the skin, nervous system, and sense organs, while the endoderm layer becomes the digestive and respiratory systems. The embryoblast, also known as the inner cell mass, is the group of cells that eventually form the embryo itself.

Question 7

Fertilization usually occurs in the

Accepted Answer

Fertilization typically occurs in the Fallopian tubes, where the egg and sperm meet and combine to form a zygote. The uterus is where the fertilized egg eventually implants and develops into a fetus. The cervix is the lower part of the uterus that separates it from the vagina, and does not typically play a role in fertilization. Cilia are hair-like structures found in the Fallopian tubes that help move the egg towards the uterus, but they are not the site of fertilization.

Question 8

Twins are caused by two sperm entering the egg at the same time.

Accepted Answer

Twins can be identical (resulting from one fertilized egg splitting into two embryos) or fraternal (resulting from two separate eggs being fertilized by two separate sperm). In the case of fraternal twins, two separate sperm fertilize two separate eggs, rather than two sperm entering the same egg.

Question 9

More than 50% of fertilized eggs fail to implant on the wall of the uterus.

Accepted Answer

This is true. It is estimated that around 50-75% of fertilized eggs fail to implant on the uterine wall, often because they are not viable or have chromosomal abnormalities.

Question 10

The __________period is the first 2 weeks after fertilization.

Accepted Answer

The germinal period is the first 2 weeks after fertilization, during which the zygote undergoes cell division and becomes a blastocyst.

Question 11

Which of the following chromosomal patterns is a girl?

Accepted Answer

The XX chromosomal pattern is associated with females.

Question 12

Which layer develops into the nervous system?

Accepted Answer

The nervous system develops from the ectoderm layer during embryonic development.

Question 13

How long is human gestation?

Accepted Answer

Human gestation is typically around 40 weeks, which is approximately 9 months, but not exactly 300 days.

Question 14

Cell division in gametes is achieved by

Accepted Answer

Gametes undergo meiosis to reduce their chromosome number by half, creating haploid cells for sexual reproduction.

Question 15

Biologically,ova and sperm are known as

Accepted Answer

Ova and sperm are both gametes, which are specialized reproductive cells that fuse during fertilization to form a zygote. Gametes are produced through a process called meiosis, which allows for the genetic diversity necessary for sexual reproduction. Therefore, option B - Gametes is the correct choice.

Question 16

A man releases about _______________ sperm in each ejaculation.

Accepted Answer

On average, a man releases about 300 million sperm in each ejaculation.

Question 17

Of the sperm released during intercourse,about __________ reach the egg.

Accepted Answer

The answer of Of the sperm released during intercourse,about __________...

Question 18

The embryoblast becomes the placenta.

Accepted Answer

The embryoblast does not become the placenta. The embryoblast develops into the embryo, while the placenta is formed from maternal and fetal tissues.

Question 19

About how many ripened ova does a woman have during her reproductive life?

Accepted Answer

A woman releases about 400 ripened ova (eggs) during her reproductive life, typically one per menstrual cycle.

Question 20

A fertilized egg is called a zygote.

Accepted Answer

A fertilized egg is indeed called a zygote.

Quiz 3: Prenatal Development