Biology 3: Embryogenesis Development

Question 1

Ampulla

Answer 1

widest part of the fallopian tube

Question 2

Cortical reaction

Answer 2

a release of calcium ions

these calcium ions depolarize the membrane of the ovum

Question 3

Two purposes of the calcium ions depolarizing the membrane:

Answer 3

prevents the fertilization of the ovum by multiple cells

increased calcium concentration increases the metabolic rate of the new zygote

Question 4

Indeterminate cleavage

Answer 4

results in cells that when isolated can still develop into complete organisms

Question 5

Determinate cleavage

Answer 5

results in cells with fates that are already determined

Question 6

Morula

Answer 6

solid mass of cells

Question 7

Blastula

Answer 7

hollow ball of cells with a fluid-filled inner cavity - (blastocoel)

Question 8

Trophoblast cells

Answer 8

surround the blastocoel and give rise to the chorion and later the placenta

Question 9

Chorion

Answer 9

extra-embryonic membrane that develops into the placenta

interface between maternal blood and the embryo

Question 10

Chorionic villi

Answer 10

microscopic fingerlike projections that penetrate the endometrium

Question 11

Yolk Sac

Answer 11

site of early blood cell development before the development of placenta

Question 12

Allantois

Answer 12

involved in early fluid exchange between the embryo and the yolk sac

Question 13

Amnion

Answer 13

thin, tough membrane filled with amniotic fluid

acts as a shock absorber

outer membrane is formed by the chorion

Question 14

Induction

Answer 14

ability of one group of cells to influence the fate of other nearby cells

Question 15

Neural crest cells

Answer 15

migrate outward to form the peripheral nervous system

Question 16

Teratogens

Answer 16

substances that interfere with development, causing defects or even death of the developing embryo

genetics of an individual embryo interferes with the formation of these

Question 17

Determination

Answer 17

irreversible commitment of a cell to having a particular function in the future

can occur through unbalanced distribution of mRNAs and protein in mitosis

can occur through secretion of morphogens from nearby cells

Question 18

Morphogens

Answer 18

chemicals that cause nearby cells to follow a particular developmental pathway

Question 19

Totipotent

Answer 19

include embryonic stem cells

can ultimately differentiate into any cell types, either in the fetus or placental structures

present in the blastula

Question 20

Pluripotent

Answer 20

can differentiate into any cell type in fetal structures

cannot differentiate into cell types in placental structures

brought about by gastrulation

Question 21

Multipotent

Answer 21

can differentiate into multiple types of cells within a particular group

ex. hematopoietic stem cells

Question 22

Juxtacrine

Answer 22

a cell communicating by directly stimulating receptors of the adjacent cell

Question 23

Growth factors

Answer 23

peptides that promote differentiation and mitosis

Question 24

Senescence

Answer 24

biological aging as a result of disrupted metabolism, accumulated changes in molecular and cellular structure

Question 25

Fetal hemoglobin

Answer 25

exhibits a greater affinity for oxygen than does maternal hemoglobin

Question 26

Umbilical arteries

Answer 26

carry **deoxygenated** blood **away** from the fetus to the placenta

Question 27

Umbilical vein

Answer 27

carries **oxygenated** blood **toward** the fetus from the placenta

Question 28

Foramen ovale

Answer 28

one-way valve that connects the fetal **right atrium to the left atrium** avoids the right ventricle and pulmonary circulation the right side of the fetal heart has higher pressure, so it is able to push blood left, but this disparity normalizes after birth

Question 29

Ductus arteriosus

Answer 29

shunts leftover blood from the **pulmonary artery to the aorta**

Question 30

Three phases of birthing:

Answer 30

1. cervix thins out and the amniotic sac ruptures (**water breaks**) 2. strong uterine contractions that result in the birth of a fetus (**birth**) 3. placenta and umbilical cord are expelled (**after birth**)

Question 31

What comprises the umbilical cord?

Answer 31

allantois and yolk sac

Question 32

gastrula

Answer 32

hollow **cup-shaped** structure having **three layers of cells**

Question 33

what is the difference between deuterostomes and protostomes

Answer 33

**deuterostomes** - blastopore becomes the organism's future **anus** **protostomes** - blastopore becomes the organism's future **mouth**

Question 34

what does the ectoderm go on to form?

Answer 34

**epidermis** and **nervous tissue**

Question 35

what does the mesoderm go on to form?

Answer 35

musculoskeletal, circulatory, gonads, digestive, respiratory systems

Question 36

what does the endoderm go on to form?

Answer 36

**internal linings** of digestive and respiratory

Question 37

inducers

Answer 37

chemical substances secreted from organizing cells to responsive cells to influence induction ex. growth factors, morphogens

Question 38

what layer of the gastrula is the adrenal cortex formed from?

Answer 38

mesoderm

Question 39

what layer of the gastrula is the adrenal medulla formed from?

Answer 39

ectoderm (it's nervous tissue)

Question 40

what is the difference between **specification**, **determination**, and **differentiation**?

Answer 40

**specification** - reversible designation of a cell to a specific cell type **determination** - irreversible designation of a cell **differentiation** - change in cell structure, function, biochemistry to match cell type

Question 41

placenta

Answer 41

organ that **develops from uterus** during pregnancy allows **nutrient, gas, waste exchange** through diffusion provides **immune protection** and has **endocrine** function makes **progesterone**, **estrogen**, **hCG**

Question 42

Which substances can cross the placenta?

Answer 42

TOxoplasma gondii Rubella Cytomegalovirus HErpes Syphilis ***TORCHES cross placenta***

Question 43

what are the three shunts to direct blood away from the fetal liver and lungs for development?

Answer 43

foramen ovale ductus arteriosus ductus venous

Question 44

Ductus venosus

Answer 44

shunt that transports blood from the **umbilical vein to the inferior vena cava** bypasses the liver, which gets a small amount of blood from the **hepatic arteries**