Embryogenesis and Development

Question 1

What sex are embryos by default?

Answer 1

female <3

Question 2

Fertilization usually occurs in the…?

Answer 2

ampulla

Question 3

Acrosomal apparatus

Answer 3

the first sperm to come in contact with the secondary oocyte’s cell membrane, forms a tubelike structure

Question 4

Cortical reaction?

Answer 4

after the sperm penetrates the cell membrane, a release of calcium ions occurs; the calcium ions depolarize the membrane of the ovum, prevents fertilization of the ovum by multiple sperm cells and increased calcium concentration increases the metabolic rate of the newly formed zygote

Question 5

Cleavage (for cells)

Answer 5

as the zygote moves to the uterus for implantation, the zygote undergoes rapid mitotic cell divisions in a process called cleavage!

indeterminate and determinate cleavage

Question 6

indeterminate cleavage

Answer 6

cells that can still develop into complete organisms

Question 7

determinate cleavage

Answer 7

results in cells with fates that are already determined; committed to differentiating into a certain type of cell

Question 8

morula

Answer 8

embryo becomes a solid mass of cells

Question 9

blastula

Answer 9

when morula undergoes blastulation, in which the blastula, a hollow ball of cells with a fluid-filled inner cavity known as a blastocoel; mammal’s are called blastocyst

Question 10

chorionic villi

Answer 10

microscopic fingerlike projections that penetrate the endometrium

Question 11

yolk sac

Answer 11

what the embryo is supported by until the placenta is fully functional

Question 12

allantois

Answer 12

involved in early fluid exchange between the embryo and the yolk sac, ultimately, the umbilical cord is formed from remnants of the yolk sac and the allantois, allantois is surrounded by the amnion, a thin, tough membrane filled with amniotic fluid

Question 13

gastrulation

Answer 13

generation of three distinct cell layers

Question 14

archenteron

Answer 14

membrane invagination into the blastocoel, later develops into the gut, opening of this is called the blastopore, turns into the anus (in deuterostomes), like humans, in protostomes, it turns into the mouth

Question 15

ectoderm

Answer 15

outermost layer, gives rise to the integument, including the epidermis, hair, nails, and the epithelia of the nose, mouth, and lower anal canal, the lens of the eye, nervous system (including adrenal medulla), and inner ear are also derived from ectoderm

Question 16

mesoderm

Answer 16

develops into several systems including the musculoskeletal, circulatory, and most of the excretory systems, gives rise to gonads as well as the muscular and connective tissue layers of the digestive and respiratory systems and the adrenal cortex

Question 17

endoderm

Answer 17

epithelial linings of the digestive and respiratory tracts, including the lungs, pancreas, thyroid, bladder, and distal urinary tracts, as well as parts of the liver, are derived from endoderm

Question 18

selective transcription

Answer 18

only the genes that are needed for a particular cell are transcribed

Question 19

induction

Answer 19

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

Question 20

inducers

Answer 20

diffuse from organizing cells to the responsive cells, chemicals are responsible for processes such as the guidance of neuronal axons

Question 21

neurulation

Answer 21

development of the nervous system, can occur once the three germ layers are formed

Question 22

teratogens

Answer 22

substances that interfere with development ex. alcohol or high blood glucose

Question 23

specification

Answer 23

cell is reversibly designated as a specific cell type

Question 24

determination

Answer 24

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

Question 25

morphogens

Answer 25

molecules that can cause a neighboring cell to follow a particular developmental pathway

Question 26

differentiation

Answer 26

changing the structure, function, and biochemistry of the cell to match the cell type

Question 27

totipotent

Answer 27

cells that can differentiate into any cell type, either fetal of placental

Question 28

pluripotent

Answer 28

cells that can differentiate into any cell type in the fetus

Question 29

multipotent

Answer 29

cells that can differentiate into multiple cell types within a particular group

Question 30

autocrine signals

Answer 30

act on the same cell that secreted the signal in the first place

Question 31

paracrine signals

Answer 31

act on cells in the local area

Question 32

juxtacrine signals

Answer 32

do not usually involve diffusion, but involve a cell directly stimulating receptors of an adjacent cell

Question 33

endocrine signals

Answer 33

involve secreted hormones that travel through the bloodstream to a distant target tissue

Question 34

Growth factors

Answer 34

often inducers, peptides that promote differentiation and mitosis in certain tissues

Question 35

apoptosis

Answer 35

programmed cell death

Question 36

necrosis

Answer 36

process of cell death in which a cell dies as a result of injury

Question 37

senescence

Answer 37

biological aging

Question 38

What happens as a cell divides ?

Answer 38

It’s telomeres/end of chromosomes will shorten

Question 39

umbilical arteries

Answer 39

carry blood away from the fetus, carry deoxygenated blood

Question 40

umbilical veins

Answer 40

carry blood towards the fetus from the placenta, carries oxygenated blood

Question 41

Does a fetus depend on its own lungs and liver?

Answer 41

No, it has shunts to direct blood away from them while they develop

Question 42

Foramen ovale

Answer 42

one-way valve that connect the right atrium to the left atrium , allows blood that enters the right atrium from the inferior vena cava to flow into the left atrium instead of the left atrium instead of the right ventricle and thereby be pumped through the aorta

Question 43

Ductus arteriosus?

Answer 43

Shunts leftover blood in the pulmonary artery to the aorta

Question 44

Ductus venosus?

Answer 44

liver is bypassed by this shunt, blood returning from the placenta via the umbilical vein directly into the inferior vena cava, liver still receives some blood supply from smaller hepatic arteries in the systemic circulation

Question 45

Parturition

Answer 45

vaginal childbirth, accomplished by rhythmic contractions of the uterine smooth muscle, coordinated by prostaglandins and the peptide hormone oxytocin

1. water breaks
2. birth of child
3. expulsion of placenta and umbilical cord (afterbirth)