Question 1

As part of embryonic development, the neural tube will become the _____.

Accepted Answer

The neural tube is a structure that develops early in embryonic development and will eventually give rise to the central nervous system, including the brain and spinal cord. Choice A (reproductive organs) and B (intestinal tract) develop from other germ layers and are not derived from the neural tube. Choice C (backbone, legs, and arms) develop from the mesoderm germ layer.

Question 2

Jenny just learned that she is 6 weeks pregnant. She is in the _____ period of prenatal development.

Accepted Answer

At 6 weeks pregnant, Jenny is in the embryonic period of prenatal development, which lasts from 2-8 weeks after conception. During this time, the major organs and body systems begin to form. The germinal period is the first 2 weeks after conception, in which the zygote divides and implants in the uterus. The fetal period is the last 7 months of pregnancy, in which the fetus grows and matures. The second period does not refer to any specific stage of prenatal development.

Question 3

By the end of the ____prenatal month, sex organs develop and are soon visible via ultrasound.

Accepted Answer

It is during the third prenatal month (around week 12) that sex organs begin to differentiate and become visible through ultrasound.

Question 4

At the onset of the embryonic period, the _____ appears. It will eventually become the neural tube.

Accepted Answer

The primitive streak appears at the onset of the embryonic period and is the first sign of gastrulation. It eventually gives rise to the three germ layers which differentiate into all of the body's tissues and organs. The neural tube, which will become the brain and spinal cord, forms from the ectoderm layer.

Question 5

Johnny's mom is four months pregnant. Johnny is anxious for the new baby and asks, "How many more months until I'm a big brother?" His mother says he has to wait about _____ more months.

Accepted Answer

A typical pregnancy lasts about 9 months. Since Johnny's mom is 4 months pregnant, there are about 5 more months to go.

Question 6

The longest period of prenatal development is the _____ period.

Accepted Answer

The fetal period is the longest period of prenatal development, lasting from the 9th week of gestation until birth. The embryonic period only lasts from weeks 3-8, the germinal period only lasts for the first 2 weeks, and the proximodistal period refers to the pattern of development within the fetal period.

Question 7

The head begins to take shape in the _____ week after conception.

Accepted Answer

The answer of The head begins to take shape in...

Question 8

Cindy is doing a presentation on prenatal development and wants to present the three main periods of prenatal development in order from conception to birth. Cindy's presentation uses the following order:

Accepted Answer

The three main periods of prenatal development are germinal, embryonic, and fetal, in that order. Germinal period includes conception to 2 weeks, embryonic period includes 3rd to the 8th week, and fetal period includes 9th week to birth. Choice C presents the correct order.

Question 9

The third period of gestation is the _____ period.

Accepted Answer

The third period of gestation is the fetal period, which begins at the end of the eighth week after fertilization and lasts until birth.

Question 10

Many obstetricians date the onset of pregnancy from the date of _____.

Accepted Answer

Obstetricians typically date the onset of pregnancy from the first day of the woman's last menstrual period, as it is difficult to determine the exact date of conception or implantation. This is known as the "gestational age" of the fetus.

Question 11

Prenatally, development happens in a "near-to-far" pattern known as _____.

Accepted Answer

Proximodistal development refers to the pattern of growth and development that occurs from the center of the body outwards, with control of the trunk and inner structures developing before control of the limbs and outer structures. This pattern is seen prenatally as well, with the development of the spinal cord and brainstem preceding the development of the limbs. Cephalocaudal refers to the pattern of development that occurs from the head down, and while it is also seen prenatally, it is not as applicable to the developmental pattern described in the question. Neurogenesis and synaptogenesis both refer to specific processes in brain development and do not describe the overall pattern of prenatal development.

Question 12

During the germinal period, the first task of the zygote's outer cells is _____.

Accepted Answer

During the germinal period, the zygote moves down the fallopian tube and begins to implant itself in the lining of the uterus. Therefore, the first task of the zygote's outer cells is implantation.

Question 13

During the germinal period of prenatal development, some cells become part of the brain, some become part of the leg, and some become part of the stomach, etc. The term for this process is _____.

Accepted Answer

During the germinal period, cells differentiate into specific types of cells that will eventually form different parts and organs of the body. This process is called differentiation. Option A, duplication, refers to the process of a cell cloning itself, whereas option B, division, refers to the process of a cell dividing into two or more daughter cells. Option D, specialization, refers to the process of cells becoming highly adapted for their specific function, which can occur after differentiation has taken place.

Question 14

A pregnant woman is having an ultrasound done eight weeks into prenatal development. She is surprised by the size of the embryo's head when she sees the image on the screen. The doctor reassures her that this is typical and due to the _____ pattern of development.

Accepted Answer

The cephalocaudal pattern of development means that growth and development proceed from the head down to the rest of the body. This is why, at eight weeks into development, the embryo's head appears proportionally larger than the rest of its body.

Question 15

What happens to the brain during the fetal period of development?

Accepted Answer

During the fetal period of development, the brain increases in size as the neurons continue to develop and migrate to their appropriate locations in the brain.

Question 16

The age of viability is the time when the preterm newborn _____.

Accepted Answer

The age of viability is the point at which a preterm infant has developed enough to possibly survive outside the uterus, typically defined as around 24 weeks of gestation. While the preterm newborn may still have some developmental milestones yet to achieve, such as completing organ development, the ability to survive outside the uterus is the defining characteristic of viability. Therefore, choice A is the best answer.

Question 17

The germinal period ends approximately _____ after conception.

Accepted Answer

The germinal period is the first stage of prenatal development and lasts approximately two weeks after conception. During this period, the zygote (fertilized egg) undergoes rapid cell division and eventually implants in the uterine wall.

Question 18

About _____ percent of natural conceptions never implant.

Accepted Answer

Approximately 50% of natural conceptions never implant. This typically occurs before the woman is even aware she is pregnant and is often due to chromosomal abnormalities in the developing embryo.

Question 19

About a week after conception, the outer layer of the multiplying cells forms a protective circle, or shell, that will become the _____.

Accepted Answer

The outer layer of cells that forms a protective circle around the developing embryo is known as the trophoblast. This trophoblast will eventually become the placenta, which is responsible for providing nutrients and oxygen to the developing fetus, as well as helping to remove waste products from the fetal blood. The umbilical cord is a flexible tube that connects the fetus to the placenta, while vernix is a waxy substance that covers the skin of the fetus and helps protect it from the amniotic fluid. The infant is the fully developed baby that is born after approximately 40 weeks of pregnancy.

Question 20

In the fourth week after conception, a miniscule blood vessel that will become the _____ begins to pulsate.

Accepted Answer

The formation of the heart begins around the fourth week after conception, and at this stage, a tiny blood vessel that will become the heart starts to beat or pulsate. This forms the basis for the development of the circulatory system in the embryo. Therefore, option D (heart) is the correct answer.

Quiz 4: Seciton 3: Beginnings: Parental Development and Birth