Question 1

Monozygotic twins __________.

Accepted Answer

Monozygotic twins come from a single fertilized egg that splits into two embryos. Since they come from the same fertilized egg, they have the same genetic material and are therefore genetically identical.

Question 2

Which kind of cells that form during the germinal period are being examined by researchers for their use in growing new organs and tissues for transplant or repairing neurological damage?

Accepted Answer

Stem cells are the type of cells being examined for their potential use in growing new organs and tissues for transplant or repairing neurological damage. Stem cells are pluripotent, meaning they have the potential to develop into various types of specialized cells in the body.

Question 3

Ali and her husband are thrilled as they peer into Ali's uterus by means of an ultrasound. The physician reports that the pregnancy appears normal, and that their baby's fingers, toes, heart, and circulatory system are developing as expected. The couple learns that the baby is only an inch long. Given this information, the current stage of prenatal development is the __________ period.

Accepted Answer

The embryonic period is characterized by the development of basic structures such as fingers, toes, heart, and circulatory system, and typically occurs from the 2nd to the 8th week of pregnancy, which aligns with the description of the baby being only an inch long.

Question 4

__________ develop when two eggs each get fertilized by different sperm cells, resulting in two zygotes in the uterus at the same time.

Accepted Answer

Dizygotic twins develop when two separate eggs are fertilized by different sperm cells, resulting in two zygotes in the uterus at the same time. Monozygotic twins, on the other hand, develop when a single fertilized egg splits into two embryos, while identical twins refer to monozygotic twins who have the same genetic makeup. "Wombmates" is not a biological term and is not a correct answer.

Question 5

Misaki is at a point in her pregnancy during which the major organs and structures of her baby are first developing. Which period of prenatal development is Misaki currently experiencing?

Accepted Answer

The embryonic period is the first period of prenatal development, which lasts from conception to the end of the eighth week of pregnancy. During this period, major organs and structures are formed, which is what Misaki is currently experiencing. The germinal period is the first two weeks of development, during which the zygote attaches to the uterine wall and begins to form a placenta. The placental period refers to the latter part of pregnancy, during which the placenta grows and supports the developing fetus. The fetal period begins at the end of the eighth week of pregnancy and lasts until birth, during which time the fetus grows and develops further.

Question 6

The union of the ovum and sperm is called ________.

Accepted Answer

Fertilization is the process of the union of the ovum and sperm, leading to the formation of a zygote. The zygote then divides and develops into an embryo during the embryonic period, which is followed by the fetal period of development.

Question 7

The placenta is __________.

Accepted Answer

The placenta is a specialized organ that forms during pregnancy and provides nourishment and filters waste products from the developing baby. Option A describes the umbilical cord, which is the tube through which a developing baby receives nourishment. Option B describes the navel, also known as the belly button, which is a scar left by the umbilical cord that attached the baby to the placenta. Option D describes the embryo, which is the name for the developing organism from fertilization to 8 weeks gestation.

Question 8

The study of ethical and moral issues brought about by new advances in biology and medicine is called __________.

Accepted Answer

Bioethics is the field that deals with ethical and moral questions that arise from advances in the biological and medical sciences. Germinal staging is not a term used in bioethics. Axiology is the study of value and ethics but is not specific to biology and medicine. Twenty-first-century moral standards is a vague and broad term that does not specifically refer to the study of ethical and moral issues in biology and medicine.

Question 9

Julia's child has facial deformities, a smaller-than-normal head, intellectual disability, learning difficulties, and delayed growth. If these defects can be traced to a teratogen used by Julia when she was pregnant, which was she most likely abusing?

Accepted Answer

Alcohol is known to be a potent teratogen that can cause a range of physical and cognitive abnormalities in babies if consumed during pregnancy. The specific defects described in the question, such as facial deformities, intellectual disability, and delayed growth, are commonly associated with fetal alcohol syndrome (FAS). While other drugs of abuse can also harm the developing fetus, alcohol is the most likely culprit given the combination of symptoms described.

Question 10

Which of the following accurately describes the way in which monozygotic twins occur?

Accepted Answer

Monozygotic (identical) twins occur when a single egg is fertilized by a single sperm and the resulting zygote splits into two separate embryos, each with its own amniotic sac and placenta. This is known as embryo twinning.

Question 11

Ashley and Mary-Kate are twins who are genetically identical. What type of twins are they?

Accepted Answer

Ashley and Mary-Kate, being genetically identical, are monozygotic twins, meaning they developed from a single fertilized egg that split into two embryos.

Question 12

Tamika and Tyrone are twins who developed from two separate fertilized ova that were fertilized by two different sperm. What type of twins are they?

Accepted Answer

Tamika and Tyrone are dizygotic (fraternal) twins, meaning they developed from two separately fertilized eggs. Monozygotic twins develop from a single fertilized egg that splits into two embryos, while maternal twins is not a recognized term for twin types. Wombmates is not a recognized term for twin types either.

Question 13

The germinal period occurs __________.

Accepted Answer

The germinal period occurs during the first two weeks after fertilization, when the zygote travels down the fallopian tube and undergoes cell division to form a blastocyst, which eventually implants in the uterus.

Question 14

Which of the following terms is used to describe any substance, such as a drug, chemical, or virus, that can bring about a birth defect?

Accepted Answer

A teratogen is any substance or agent that can cause harm to the developing fetus and result in a birth defect. These substances may include drugs, chemicals, viruses, alcohol, and more. It is important for pregnant women to be aware of potential teratogens and avoid exposure whenever possible.

Question 15

Fraternal twins are __________ similar genetically than are regular, non-twin siblings.

Accepted Answer

Fraternal twins are no more similar genetically than regular, non-twin siblings. Fraternal twins come from two separate eggs fertilized by two separate sperm, whereas regular siblings come from one egg fertilized by one sperm. Therefore, fraternal twins share approximately 50% of their genetic material like any other siblings, while identical twins share nearly 100% of their genetic material.

Question 16

Fiona is at a point in her pregnancy when the zygote is moving down to her uterus, and the placenta and umbilical cord are beginning to form. Which period of prenatal development is Fiona currently experiencing?

Accepted Answer

The germinal period is the first two weeks after conception, during which the zygote moves to the uterus and the placenta and umbilical cord begin to form.

Question 17

Times during which some environmental influences can have a major impact on development are called __________ periods.

Accepted Answer

Critical periods are times during development when certain experiences must occur for development to proceed normally, or when exposure to certain experiences is particularly influential.

Question 18

The specialized organ that provides nourishment and filters away waste products from the developing baby is called the __________.

Accepted Answer

The placenta is a specialized organ that develops during pregnancy and acts as a connection between the mother and the developing baby. The placenta is responsible for providing nourishment and oxygen to the baby as well as filtering away waste products such as carbon dioxide. The uterus is the organ in which the baby develops, but it does not provide nourishment or filter waste products. The umbilical cord is the structure that connects the developing baby to the placenta and allows for exchange of nutrients and waste products, but it is not the specialized organ itself. The embryo is the early stage of development before the placenta has formed.

Question 19

In the process of fertilization, the __________ and __________ unite, resulting in a single cell.

Accepted Answer

Fertilization is the process where a sperm cell and an ovum (egg cell) unite, resulting in the formation of a zygote, which is a single cell that contains all the genetic information needed to form a new individual.

Question 20

Which of the following accurately describes the embryonic period?

Accepted Answer

The embryonic period is the period during which the major organs and structures of the organism first develop. This typically occurs during the first 8 weeks of pregnancy.

Quiz 8: Development Across the Life Span