Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

DAT prep > Developmental biology > Flashcards

Developmental biology Flashcards

1
Q

over the course of 9 months, a human zygote undergoes ___, ____ and _____ in preparation for life outside the uterus

A

cell division, cellular differentiation and morphogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

2 early developmental stages

A

fertilization and cleavage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

when does fertilization occur in mammals?

A

12-24 hours after ovulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

where does fertilization occur?

A

in the lateral, widest portion of the oviduct where sperm travelling from the vagina encounter an egg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what may result from the fertilization of more than one egg?

A

fraternal (dizygotic) twins may be conceived

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What occurs when one zygote divides into two separate embryos?

A

identical (monozygotic) twins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

early embryonic development is characterized by a series of rapid mitotic divisions known as ____

A

cleavage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

during cleavage, what happens to the total volume of the cytoplasm?

A

it remains constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

cleavage results in progressively smaller cells with an increasing ratio of ___ to ___

A

nuclei to cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When do the first, second, and third complete cleavage of zygote occur?

A

1st: approx 32 hours after fertilization
2nd: approx 60 hours “”
3rd: approx 72 hours “”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how many cells are present following 3 complete cleavages of the zygote?

A

8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

define morula

A

once embryo reaches the uterus, cell division continues and forms a SOLID BALL OF EMBRYONIC CELLS known as morula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is blastulation?

A

process by which a morula develops a fluid-filled cavity called the BLASTOCOEL, which by the fourth day becomes a hollow sphere of cells called the BLASTULA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the name of the stage of the embryo which implants in the uterus?

A

blastula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What occurs in an ectopic pregnancy?

A

embryo implants outside the uterus (e.g., in the Fallopian tube)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe gastrulation

A

After week 2, the embryo is fully implanted in the uterus and cell migrations transform the single cell layer of the blastula into a THREE-LAYERED STRUCTURE called a GASTRULA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

3 primary germ layers:

A
  1. ectoderm
  2. endoderm
  3. mesoderm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what structures does each primary germ layer give rise to?

A
  1. ectoderm: INTEGUMENTARY SYSTEM (including the EPIDERMIS, hair, nails, and epithelium of the nose, mouth, and anal canal), the LENS OF THE EYE, the RETINA, and the NERVOUS SYSTEM.
  2. endoderm: EPITHELIAL LININGS OF THE DIGESTIVE AND RESPIRATORY TRACTS (including the lungs) and parts of the LIVER, PANCREAS, THYROID, and BLADDER LINING
  3. mesoderm: MUSCULOSKELETAL SYSTEM, CIRCULATORY SYSTEM, EXCRETORY SYSTEM, GONADS, CONNECTIVE TISSUE THROUGHOUT THE BODY, and portions of the DIGESTIVE and RESPIRATORY ORGANS.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

define neurulation

A

neurulation occurs after gastrulation and is the process by which regions of the germ layers begin to DEVELOP INTO A RUDIMENTARY NERVOUS SYSTEM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When does neurulation occur?

A

before week 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The rod of ______ cells is called the notochord

A

mesodermal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what kind of effect does the notochord have on the overlying ectoderm? What occurs?

A

the notochord has an INDUCTIVE EFFECT on the overlying ectoderm, causing it to BEND INWARD and form a GROOVE along the dorsal surface of the embryo.
The dorsal ectoderm FOLDS on either side of the tube, forming the NEURAL TUBE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

the neural tube gives rise to:

A

the brain and spinal cord (CNS)

24
Q

the cells at the tip of each neural fold are called the ___ ___ ___

A

neural crest cells

25
Q

neural crest cells give rise to:

A

many components of the PNS, including the sensory ganglia autonomic ganglia, adrenal medulla, and Shwann cells

26
Q

what causes spina bifida?

A

When the neural tube does not close properly during its development

27
Q

3 components of development (following neurulation)

A
  1. organogenesis
  2. growth
  3. gametogenesis
28
Q

What occurs in organogenesis?

A

the body organs begin to form.

Cells interact, differentiate, change physical shape, proliferate, and migrate.

29
Q

What happens during the developmental process of growth?

A

organs increase in size.

Continual process from infancy through childhood to adulthood.

30
Q

What happens in gametogenesis?

A

eggs develop in women and sperm develop in men, which allows for reproduction.

31
Q

Two components of specialized circulatory system which supplies fetus with oxygen

A

placenta and umbilical cord

32
Q

4 extra-embryonic membranes formed during development:

A
  • amnion
  • chorion
  • allantois
  • yolk sac
33
Q

define amnion

A

the amnion is a thin, tough membrane containing a watery fluid called amnionic fluid.

34
Q

role of amniotic fluid

A

SHOCK ABSORBER of external pressure during gestation and localized pressure from uterine contractions during labour.

35
Q

Placenta formation begins with the ____, a membrane that completely surrounds the amnion.

A

chorion

36
Q

role of chorion

A

assists with the transfer of nutrients from the mother to the fetus

37
Q

what does the allantois become?

A

The allantois develops as an outpocketing of the gut.
The blood vessels of the allantoic wall enlarge and become the UMBILICAL VESSELS, which will connect the fetus to the developing placenta.

38
Q

the yolk sac is the site of early development of ___ ____ and becomes associated with the umbilical ___

A

the yolk sac is the site of early development of BLOOD VESSELS and becomes associated with the umbilical VESSELS

39
Q

3 stages of labor

A
  • First: cervix thins and dilates, amnionic sac ruptures, mild contractions.
  • Second: rapid contractions, birth of baby.
  • Third: uterus contracts, expelling the placenta and the umbilical cord.
40
Q

chemicals and biological agents that cause congenital disorders are called ____

A

teratogens

41
Q

define “vertical transmission”

A

when a mother passes on an infection directly to her developing offspring.
Can occur either during development or during birth.

42
Q

Plant embryo consists of 5 parts:

A
  1. epicotyl
  2. cotyledons
  3. hypocotyl
  4. endosperm
  5. seed coat
43
Q

epicotyl is precursor of…

A

epicotyl is precursor of the UPPER STEM AND LEAVES

44
Q

cotyledons

A

SEED LEAVES

45
Q

dicots have __ seed leaves, while monocots have ___

A

dicots have TWO seed leaves, while monocots have ONE

46
Q

hypocotyl

A

the lower stem and root

47
Q

endosperm

A

feeds the embryo

48
Q

what happens to endosperm in dicots?

A

cotyledon absorbs the endosperm

49
Q

seed coat

A

develops from the outer covering of the ovule.

The embryo and its seed coat together comprise the seed.

50
Q

embryonic cells in higher plants are called ____ ____

A

meristem cells

51
Q

where is apical meristem found?

A

in the tips of the roots and stems

52
Q

growth in length of plants occurs only at:

A

tips of roots and stems

53
Q

location of lateral meristem

A

lateral meristem (or cambium) is located between the xylem and phloem.

54
Q

What tissue in plants allows for growth in diameter and can differentiate into new xylem and phloem cells?

A

lateral meristem (cambium)

55
Q

Membrane which stores and transports wastes from the fetus to the placenta in mammals?

A

allantois

56
Q

The _____ ____functions to provide nutrients to a developing placental fetus, only until the placenta is ready to take over that role

A

The YOLK SAC functions to provide nutrients to a developing placental fetus, only until the placenta is ready to take over that role

DAT prep (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions