Chapter 18: Development and aging

Question 1

What is fertilization and where does it occur?

Answer 1

the union of egg and sperm and occurs in the oviduct

Question 2

Define the Zone pellucida

Answer 2

the matrix surrounding the egg

Question 3

What is the corona radiata?

Answer 3

Follicular cells surrounding the zone pellucida

Question 4

What is the acrosome?

Answer 4

the head of the sperm that has enzymes to beak through the zona pellucida.

Question 5

What are the cortical granules/vesicles?

Answer 5

releases enzymes and prevent polyspermy.

Question 6

What is polyspermy?

Answer 6

an egg that has been fertilized by more than one sperm

Question 7

What is cleavage and when does it occur?

Answer 7

cleavage is the mitotic cell division of the zygote to form the morula. it occurs during the pre-embryonic stage (the first week)

Question 8

What is morphogenesis?

Answer 8

the embryo takes shape

Question 9

What is cell differentiation?

Answer 9

cells take on a specific structure and function.

Question 10

What system is the first visible system?

Answer 10

the nervous system

Question 11

Name the four extraembyronic membranes:

Answer 11

chorion, allantois, yolk sac, and amnion.

Question 12

Brief description of chorion:

Answer 12

fetal half of the placenta

Question 13

Brief description of allantois:

Answer 13

forms bladder and the umbilical cord blood vessels

Question 14

Brief description of the yolk sac:

Answer 14

first site of blood cell formation

Question 15

Brief description of amnion:

Answer 15

contains amniotic fluid and protects the embryo.

Question 16

Name the 3 stages of development:

Answer 16

1. Pre-embryonic which is the first week.
2. Embryonic which is the 2nd week to 2nd month
3. Fetal and development after birth which is the third months to ninth month and the rest of their lives.

Question 17

Morula:

Answer 17

compact ball of embryonic cells.

Question 18

Blastocyte:

Answer 18

inner cell mass becomes the embryo, covered by a layer of cells. Partially hollow.

Question 19

Implantation:

Answer 19

the embryo implants in the uterine wall

Question 20

What is HCG?

Answer 20

Human chorionic gonadotropin: maintains corpus leutium and endometrium.

Question 21

PROGESTERONE PREVENTS WHAT?

Answer 21

menstruation

Question 22

The inner cell mass becomes the what?

Answer 22

embryonic disk

Question 23

Gastrulation begins in the ___ week

Answer 23

2nd`

Question 24

Define gastrulation and what does it do?

Answer 24

the movement and migration of cells to form the 3 primary germ layers endoderm, mesoderm, ectoderm,

Question 25

What system is the first system to form in the embryo?

Answer 25

nervous

Question 26

In fetal circulation, most blood is stunted into the left atrium through the:

Answer 26

foreman ovale

Question 27

The ductus arterioles and the ductus venous are both present in the:

Answer 27

fetal circulation to prevent blood from reaching the fetal lungs and the liver

Question 28

the primary functions of the placenta is to provide and do what?

Answer 28

1. nutrients and oxygen
2. Remove waste products from baby’s blood
3. Takes pace of the lungs and liver in the uterus during development

Question 29

When this gene is present, the gonads will develop into the testes:

Answer 29

SRY gene and its found on the Y chromosome.

Question 30

What do the mullerian and wolffian ducts develop into?

Answer 30

Mullerian: female oviducts and uterus
Wolffian: male reproductive duct system

Question 31

What is parturition and how many stages are there?

Answer 31

Parturition is birth and there are 3 stages: effacement and dilation, uterine contractions, and placenta is expelled.

Question 32

What are telomeres and what do they do?

Answer 32

Telomeres are short sequences of DNA found at the end of chromosomes. They stop chromosome ends from breaking during cell division.

Question 33

What are knock out mice?

Answer 33

a gene is removed from these mice and the gene that is removed is studied for its function.

Question 34

What are some effects of aging?

Answer 34

skin thins, less adipose tissue, heart shrinks, ateries are more rigid, reaction time slows, blood pressure increases, muscle mass decreases.