Question 1

According to the text,at what month can the fetus's heartbeat be heard with a stethoscope?

Accepted Answer

The text states that the fetal heartbeat can be heard with a stethoscope during the third month of pregnancy.

Question 2

What embryonic structure will become the brain and spinal cord?

Accepted Answer

The neural tube is the embryonic structure that develops into the brain and spinal cord. The brain stem (A) is part of the early brain development but does not develop into the entire brain. The neuralblast (B) is a type of cell that is involved in neural development but is not the overarching structure that becomes the brain and spinal cord. The cerebral cortex (D) is the outer layer of the brain that is responsible for cognitive functions and develops later in embryonic development.

Question 3

During the embryonic period,the endoderm is formed,which will become the ____.

Accepted Answer

During the embryonic period, the endoderm is formed which gives rise to the digestive and respiratory systems. Option A is incorrect as sensory organs and nervous system are formed from ectoderm and the skin, hair, and nails are formed from the ectoderm and mesoderm. Option B is incorrect as muscles and bones are formed from mesoderm, while reproductive and circulatory system are formed from the endoderm and mesoderm. Option D is incorrect as the endocrine system is formed from the ectoderm and mesoderm.

Question 4

At three months the average fetus _____.

Accepted Answer

At three months, the average fetus weighs around three ounces and is around three inches long. The other options are not accurate in describing the average fetus at this stage of development.

Question 5

At the end of the eighth week the embryo is only one inch long and weighs just one gram.According to the text,what can the embryo now do?

Accepted Answer

At the end of the eighth week, the embryo is able to respond to touch, meaning it has some level of neurological development. It is not yet able to step in place, suck its thumb, or vocalize.

Question 6

The outer layer of the embryonic disk will become ____.

Accepted Answer

The outer layer of the embryonic disk is called the ectoderm and it gives rise to the skin, hair, nails and the nervous system.

Question 7

During the embryonic period,the ectoderm is formed which will become the ____.

Accepted Answer

The ectoderm is one of the three primary germ layers formed during embryonic development, and it gives rise to the skin, hair, nails, sensory organs (such as the eyes and ears), and the nervous system. Therefore, choice A is the correct answer. The other choices - muscles, bones, reproductive system, circulatory system, digestive and respiratory systems, hormonal and endocrine systems - are derived from the mesoderm and endoderm germ layers.

Question 8

Nearly all of the major organs are formed during what period?

Accepted Answer

The major organs are formed during the embryonic period, which occurs within the first eight weeks of development after fertilization.

Question 9

By the end of the eighth week the embryo ____.

Accepted Answer

The answer of By the end of the eighth week...

Question 10

By the end of the fourth week the embryo's head is apparent and the eyes,nose,mouth,and ears begin to form.How long is the embryo at this point?

Accepted Answer

At the end of the fourth week, the embryo's head is beginning to form, and it is only around ¼ of an inch in length. It is still very small and in the early stages of development. Choices B, C, and D are much too large for an embryo at this stage.

Question 11

During the embryonic period,the mesoderm is formed,which will become the ____.

Accepted Answer

During the embryonic period, the mesoderm forms the muscles, bones, reproductive system, and circulatory system.

Question 12

Fernando and Rebecca are anxious to know the sex of their baby.It would not be until the end of the ____ month of pregnancy that they can find out because the genitalia will not have fully formed before then.

Accepted Answer

The answer of Fernando and Rebecca are anxious to know...

Question 13

The ____ period lasts from the ninth week after conception until birth.

Accepted Answer

The fetal period lasts from the ninth week after conception until birth. The germinal period is the first two weeks after conception, the embryonic period is from the third week until the eighth week after conception, and the zygote period is not a commonly recognized stage of prenatal development.

Question 14

The fetal period ends at birth.When does it begin?

Accepted Answer

The answer of The fetal period ends at birth.When does...

Question 15

Your friend just had her first pregnancy check-up and is just starting her second month of pregnancy.She is very upset that she was not given the chance to hear her fetus's heartbeat.Remembering what you learned in developmental class,what should you tell her?

Accepted Answer

At just starting the second month of pregnancy, it is not always possible to hear the fetus's heartbeat with a stethoscope. The fetal heartbeat can usually be heard using a fetal Doppler at around 10-12 weeks of pregnancy. It is not necessarily an indication of any problem with the fetus or the pregnancy if the heartbeat cannot be heard at this stage.

Question 16

At what rate are neurons produced during the embryonic period?

Accepted Answer

During the embryonic period, neurons are produced at a remarkable rate of 250,000 per minute.

Question 17

By the end of the third month the typical fetus can be described as "three times three" because ____.

Accepted Answer

"Three times three" implies a multiplication of three, and the only option that has three factors of three is A - three months, three ounces, and three inches long.

Question 18

By the end of the third week the neural tube begins to form.This structure will eventually become ____.

Accepted Answer

The neural tube will develop into the spinal cord and brain, which are essential components of the nervous system. Option A is incorrect because the skull and torso develop from a different process. Option B is incorrect because the development of the limbs occurs later in embryonic development. Option D is incorrect because the lungs and digestive system develop from different embryonic layers.

Question 19

Prenatal development is divided into segments.What are these segments called?

Accepted Answer

Prenatal development is typically divided into three trimesters, with each trimester representing a three-month period of fetal development. These trimesters are used as a rough framework for tracking fetal growth and development, as well as for scheduling prenatal care visits with healthcare providers.

Question 20

What is the average weight of babies at birth in developed countries?

Accepted Answer

The average weight of babies at birth in developed countries is around 7.5 pounds (3.4 kg), as per the World Health Organization (WHO). The other options are not correct as they are either too low (Option A) or too high (Option C and D) compared to the average birth weight.

Quiz 2: Genetics and Prenatal Development