Early developmental stages Flashcards Preview

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Flashcards in Early developmental stages Deck (44)
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1
Q

Fertilization is…

A

The joining of sperm and ovum

2
Q

Fertilization usually occurs in the ____ of the Fallopian tube

A

Ampulla

3
Q

How does the sperm penetrate the corona radiate and zone pelluicida?

A

By the use of acrosomal enzymes

4
Q

Once the sperm contacts the located plasma membrane … The sperm establishes the ___ and injects its nucleus

A

Acrosomal apparatus

5
Q

When the first sperm penetrates, it causes the release of what?

A

Calcium ions

6
Q

The release of calcium ions, when the sperm penetrates, prevents what?

A

Prevents additional sperm from fertilizing the egg and increases the metabolic rate of the resulting zygote - this is called cortical reaction

7
Q

A secondary locate is ovulated from the follicle on approximately what day of the cycle ?

A

Day 14

8
Q

after fertilization, the zygote travels to the..

A

uterus for implantation

9
Q

cleavage

A

when the zygote undergoes rapid mitotic cell divisions

10
Q

one of the zygotes defining characteristics is:

A

unicellularity

11
Q

by the zygote dividing into smaller cells, the cells increase two ratios:

A

nuclear to cytoplasmic ratio

surface area - to - volume ratio

12
Q

two types of cleavage:

A

indeterminate cleavage

determinate cleavage

13
Q

indeterminate cleavage

A

results in cells that can still develop into complete organisms

14
Q

determinate cleavage

A

results in cells with fates that are already determined

these cells are committed to differentiating into a certain type of cell

15
Q

morula

A

the embryo becoming a solid mass of cells

16
Q

once the moral is formed, it undergoes _______

A

blastulation

17
Q

blastulation forms the ______

A

blastula

18
Q

blastula

A

a hollow ball of cells with fluid filled inner cavity known as blastocoel

19
Q

blastocyst

A

the mammalian blastula that consists of two noteworthy cell groups - the trophoblast and inner cell mass

20
Q

trophoblast cells

A

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

specialized to create an interface between the maternal blood supply and the developing embryo

21
Q

inner cell mass

A

protrudes into the blastocoel and gives rise to the organism itself

22
Q

trophoblast cells give rise to the ______

A

chorion

23
Q

chorion

A

and extra embryonic membrane that develops in the placenta

24
Q

chorionic villi

A

formed by trophoblasts

they are microscopic fingerlike projections that penetrate the endometrium

develop in the placenta

support maternal - fetal gas exchange

25
Q

embryo is connected to the placenta by the …

A

unbilical cord

26
Q

unbilical cord consist of

A

2 arteries and 1 vein encased in a gelatinous substance

27
Q

unbilical arteries carry

A

deoxygenated blood and waste to the placenta for exchange

28
Q

until the placenta is functional, the embryo is supported by the

A

yolk sac

29
Q

early blood cell development :

A

yolk sac

30
Q

2 extra embryonic membranes :

A

allantois

amnion

31
Q

allantois

A

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

surrounded by the amnion

32
Q

amnion

A

thin, though membrane filled with amniotic fluid that serves as a shock absorber during pregnancy

33
Q

Gastrulation

A

developmental process that begins once the cell mass implants

34
Q

During Gastrulation, the _________ is formed with a ________ at the end

A

archentreron ; blastopore

35
Q

As the archenteron grows through the blastocoel, it contacts the opposite side, establishing..

A

the 3 primary germ layers

36
Q

the 3 primary germ layers

A

ectoderm
mesoderm
endoderm

37
Q

ectoderm

A

becomes epidermis, hair, nails and the epithelia of the nose, mouth, and anal canal as well as the nervous system (including the adrenal medulla) and the lends of the eye

38
Q

mesoderm

A

becomes much of the muscoskeletal, circulatory, and excretatory systems

gives rise to the gonads and the muscular and connective tissue layers of the digestive and respiratory systems as well as the adrenal cortex

39
Q

endoderm

A

becomes much of the epithelial linings of the respiratory and digestive tracts and parts of the pancreas, thyroid, bladder, and distal urinary tracts

40
Q

neurulation

A

development of the nervous system, begins after the formation of the 3 germ layers

41
Q

notochord

A

introduced a group of overlying ectoderm cells to form neural folds surrounding a neural groos

42
Q

the neural folds fuse to form the

A

neural tube; which becomes the CNS

43
Q

Neural crest cells

A

found on the tip of the neural fold

becomes the PNS as well as specific cell types in other tissues

44
Q

Teratogens

A

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

Include alcohol, certain prescription drugs, viruses, bacteria, and environmental chemicals