Embryogenesis and Development

Question 1

Acromosomal apparatus

Answer 1

Tube that extends to and penetrates the cell membrane from sperm

Question 2

Cortical reaction

Answer 2

Release of calcium ions after penetration of sperm through cell membrane
Depolarize membrane of ovum to prevent fertilization of multiple sperm and increase metabolic rate of zygote
Create fertilization membrane

Question 3

Dizygotic/fraternal twins

Answer 3

Fertilization of two different eggs from one ovulatory cycle by two different sperm
Separte placenta, chorion, and amnioni

Question 4

Monozygotic/Identical twins

Answer 4

Single zygote splits into two

Chorion/amnion types

Question 5

Cleavage

Answer 5

Zygote undergoes rapid mitotic cell division while moving to uterus for implantation

Question 6

Zygote must be

Answer 6

Unicellular, after it is an embryo

Question 7

Indeterminate cleavage

Answer 7

In cells that still develop into complete organisms (identical twins came from a indeterminately cleaved cell)

Question 8

Determinate cleavage

Answer 8

Cell fate already determined, committed to differentiating into certain cell types

Question 9

Morula

Answer 9

Solid mass of cells after after divisions

Question 10

Blastulation

Answer 10

Forms a hollow ball of cells with a fluid-filled inner cavity called a blastocoel

Question 11

Trophoblast

Answer 11

Surrounds blastocoel and gives rise to chorion and placenta

Question 12

Inner cell mass

Answer 12

Of blastula, produdes into blastocoel and gives rise to organism

Question 13

What does the embryo implant as?

Answer 13

Blastula

Question 14

Chorion

Answer 14

Extraembryonic membrane that develops into the placenta

Question 15

What does the umbilical cord contain?

Answer 15

Two arteries and one vein
Artery- deoxygenated blood
Vein- Oxygenated blood

Question 16

Chorionic villi

Answer 16

Fingerlike projections that penetrate endometrium that support fetal gas exchange

Question 17

Yolk sac

Answer 17

Early blood cell development

Supports embryo before placenta

Question 18

Allantois

Answer 18

Early fluid exchange between embryo and yolk sac

Question 19

Amnion

Answer 19

Surrounds allantois which is a membrane filled with amniotic fluid (shock absorber)

Question 20

Gastrulation

Answer 20

Generation of three distinct cell layers

Question 21

Archenteron

Answer 21

Membrane of invagination of gastrula that develops into the gut

Question 22

Blastopore

Answer 22

Opening of archenteron

Question 23

Deuterosomes

Answer 23

Humans, blastopore develops into anus

Question 24

Protosomes

Answer 24

Blastopore develops into mouth

Question 25

Ectoderm

Answer 25

Outermost layer | Epidermis, hiar, nails, epithelia, nervous system, inner ear

Question 26

Mesoderm

Answer 26

Musculoskeletal, circulatory, excretory, gonads

Question 27

Endoderm

Answer 27

Epithelial linings of digestive, respiratory tracts | Pancreas, thyroid, bladder, urinary, liver

Question 28

Where is the adrenal cortex derived from?

Answer 28

Mesoderm

Question 29

Where is adrenal medulla derived from?

Answer 29

Ectoderm

Question 30

Neurulation

Answer 30

Development of the nervous system after the germ layers are formed

Question 31

Notochord

Answer 31

Rod of mesoderm cells forms along the long axis of organism

Question 32

Neural folds

Answer 32

Notochord induces ectodermal cells to move in and produce a neural tube

Question 33

Neural crest cells

Answer 33

Migrate outward to form peripheral nervous system

Question 34

Teratogens

Answer 34

Substances that interfere with development causing defects or death- genetics changes effects

Question 35

Morphogens

Answer 35

Molecules that cause nearby cells to follow particular development

Question 36

Pluripotent

Answer 36

After formation of germ cell layers, still differentiate into any cell except those found in placental structures

Question 37

Multipotent

Answer 37

Most specialized stem cells

Question 38

Paracrine cells

Answer 38

Act on cells in a local area v. endocrine that travel

Question 39

Senescence

Answer 39

Biological aging

Question 40

What do telomeres have a high concentration of?

Answer 40

Guanine and cytosine

Question 41

Do maternal and fetal mix blood?

Answer 41

No

Question 42

Where is the higher partial pressure of oxygen, maternal or fetal blood?

Answer 42

Maternal

Question 43

What organs do not serve significant function prior to birth?

Answer 43

Lungs and liver, shunts blood away while these develop

Question 44

Foramen ovale

Answer 44

One-way valve taht conects right atrium to left atrium (higher pressure right side

Question 45

Ductus arteriosus

Answer 45

Shunts leftover blood from pulmonary artery into aorta

Question 46

When are most organs formed?

Answer 46

In first trimester by the end of 8 weeks