Deck 21 (CO): Human Development and Genetics

Question 1

The zygote begins a series of cell divisions called ___________________,and the process of cell division is called _______________________.

Answer 1

cleavage,mitosis

Question 2

The union of human _____________ and _______________,each with ___________ chromosomes,forms a zygote.

Answer 2

egg,sperm,23

Question 3

The early embryonic stage that is a solid sphere of cells is the ______________________.

Answer 3

morula

Question 4

The trophoblast of the blastocyst secretes enzymes to permit _______________________ in the uterus.

Question 5

During an average gestation period,the period of embryonic growth lasts __________ weeks and the period of fetal growth lasts _____________ weeks.

Question 6

The average human gestation period is ____________ weeks.

Question 7

During gestation,the last 32 weeks are considered the ______________________ growth period.

Question 8

The blastocyst is an early embryonic stage,and the cells of the inner cell mass are ________________________,because they are not yet specialized.

Question 9

The morula stage of early embryonic development may be described as a(n)___________________________ of cells.

Question 10

When a zygote undergoes cleavage,the process of cell division is _____________________.

Question 11

The human ___________________ has _____________ chromosomes,and is formed by the union of egg and sperm.

Question 12

Fertilization of an ovum usually takes place in the ______________________________.

Question 13

The early embryonic stage that is a hollow sphere of cells with an inner cell mass is the ____________________________.

Question 14

In the embryo,the three germ layers,or primary layers,are the ______________________,_______________________,and ________________________.

Question 15

During gestation,the first 8 weeks are considered the ________________________ growth period.

Question 16

In the embryo,the bones and muscles are derived from the _______________________.

Question 17

In the embryo,the epidermis and nervous system are derived from the ___________________.

Question 18

The part of a blastocyst that secretes enzymes to permit implantation is the ____________________.

Question 19

In the embryo,the liver and lungs are derived from the _______________________.

Question 20

Normal implantation of a blastocyst takes place in the _________________________ of the uterus.

Question 21

The chorion is the embryonic membrane that contributes to the formation of the __________________________.

Question 22

During pregnancy,the placental hormone that inhibits contractions of the myometrium is ______________________________.

Question 23

The placental hormone that maintains the corpus luteum during early pregnancy is ______________________________.

Question 24

Blood is carried from the fetus to the placenta by the _______________________,and this blood has high levels of the gas ___________________________.

Question 25

The function of the placental hormone hCG is to maintain the _______________________ during early pregnancy.

Question 26

In the placenta,oxygen and carbon dioxide move by the process of _____________________.

Question 27

The yolk sac is the embryonic membrane that forms the first _________________________.

Question 28

The embryonic membrane that forms the fetal part of the placenta is the ___________________.

Question 29

The site of exchanges between maternal blood and fetal blood is the _______________________.

Question 30

The embryonic membrane that has villi to provide for the nourishment of the early embryo is the _________________________.

Question 31

During pregnancy,an important function of progesterone is to inhibit contractions of the __________________________ of the uterus.

Question 32

In later pregnancy,the placenta secretes the hormones _________________________ and ____________________________.

Question 33

The embryonic membrane that contains fluid to cushion the embryo is the _________________.

Question 34

The hormone hCG is produced by the ____________________ of the embryo,and its effects are on the ________________________ in the ovary.

Question 35

In the placenta,nutrients are taken into fetal vessels by the process of _____________________.

Question 36

Blood is carried from the placenta to the fetus by the ________________________,and this blood has high levels of the gas ________________________.

Question 37

The umbilical vein carries blood from the _____________________ to the ____________________________.

Question 38

The amnion is the embryonic membrane that contains ______________________ to provide a(n)________________________ for the fetus.

Question 39

The embryonic membrane that forms the first blood cells is the ______________________.

Question 40

The umbilical arteries carry blood from the _____________________ to the _________________________.

Question 41

Just before birth,all of the fetus's organ systems are functioning except the ________________________ system.

Question 42

During the _______________ stage of labor,the placenta is delivered.

Question 43

During the ________________ stage of labor,the baby is delivered.

Question 44

During the _______________ stage of labor,the amniotic sac ruptures.

Question 45

After birth,the foramen ovale in the baby's __________________ is ________________,which helps increase ________________________ circulation.

Question 46

During the third stage of labor,____________________________.

Question 47

A few moments after birth,the baby's ______________________ system begins functioning because the _____________________ have inflated.

Question 48

During the first stage of labor,the _____________________ dilates and the __________________________ ruptures.

Question 49

During labor,the hormone that causes strong contractions of the uterus is ___________________.

Question 50

During pregnancy,the hormones that prepare the mammary glands for lactation are __________________________ and ________________________.

Question 51

During the _______________ stage of labor,the cervix dilates.

Question 52

The genetic code for one protein is called a(n)______________________.

Question 53

After birth,the baby's ductus arteriosus ______________________,which allows more blood to flow to the ___________________,which increases _____________________ circulation.

Question 54

During the first stage of labor,the cervix ____________________ and the amniotic sac __________________________.

Question 55

A gene is the genetic code for ___________________________.

Question 56

After birth,the ______________________ in the baby's heart is closed,which helps increase ___________________________ circulation.

Question 57

During the second stage of labor,________________________________.

Question 58

During pregnancy,the placental hormones that inhibit ovulation are _____________________ and ___________________________.

Question 59

After birth,the baby's _______________________ constricts,which prevents blood from flowing into the aorta and thereby allows more blood to flow to the ____________________.

Question 60

After birth,the baby's ductus venosus _______________________,because the umbilical cord has been cut and blood no longer enters the baby from the _________________________.

Question 61

A human cell contains _____________ pair(s)of autosomes and _____________ pair(s)of sex chromosomes.

Question 62

The two members of a homologous pair of chromosomes have genes for the ______________________________________.

Question 63

A person's genotype for a particular trait refers to the __________________________________.

Question 64

A pair of chromosomes that has maternal and paternal genes for the same traits is a(n)___________________ pair.

Question 65

Homologous chromosomes are a pair of chromosomes that may also be called ______________________ and ___________________.

Question 66

A person who is heterozygous for a particular trait has two ____________________ genes for it.

Question 67

A person's phenotype for a particular trait refers to the _________________________________.

Question 68

The expression of the genes a person has for a particular trait is called the ____________________.

Question 69

The sex chromosomes in women are called _______________.

Question 70

The sex chromosomes in _______________ are called XX,and in ______________ are called XY.

Question 71

The sex chromosomes in women are called ____________ and in men are called ____________.

Question 72

A person who is homozygous for a particular trait has two ____________________ genes for it.

Question 73

A person has two genes for each genetic trait,and these genes are called __________________ and _____________________.

Question 74

The genes a person has for a particular trait are called the _______________________.

Question 75

The possibilities for the expression of a gene are called _____________________.

Question 76

A human cell contains ________ (number)chromosomes,and 22 pairs of these are called _________________________.

Question 77

A person who has two similar genes for a particular trait is said to be ______________________ for that trait.

Question 78

A person who has two different genes for a particular trait is said to be _____________________ for that trait.

Question 79

The sex chromosomes in men are called _________________.

Question 80

The genetic code in the nucleus of a cell is contained in the __________________ of the ____________________________.