Biology - Embryology

Question 0

Where does fertilization take place?

Answer 0

Lateral portion of the Fallopian tube.

Question 1

How many hours after ovulation can an egg be fertilized?

Answer 1

12-24 hours

Question 2

What is cleavage?

Answer 2

Mitotic division

Question 3

Does protoplasm change in cleavage?

Answer 3

No. The total volume of cytoplasm remains constant.

Question 4

What is formed from repeated cleavages?

Answer 4

Smaller cells with increasing nuclear to cytoplasm ratio.

Question 5

How does the surface to volume ratio change with cleavage?

Answer 5

It increases so has exchange is improved.

Question 6

What is formed from indeterminate cleavage?

Answer 6

Cells that retain ability to become an organism…..identical twins.

Question 7

What results from determinate cleavage?

Answer 7

Cells whose future differentiation is determined at early stage.

Question 8

When does first cleavage of zygote occur?

Answer 8

32 hours after fertilization.

Question 9

When does 8-felled embryo reach the uterus?

Answer 9

After 3rd cleavage - 72 hours after fertilization.

Question 10

What is a morula?

Answer 10

Solid ball of embryonic cells.

Question 11

What is a blastula?

Answer 11

Hollow sphere of cells made from blastulation of the morula.

Question 12

When is blastula formed?

Answer 12

4 days after fertilization.

Question 13

When does embryo adhere to uterine wall?

Answer 13

As a blastula.

Question 14

What is a gastrula?

Answer 14

3 layered structure. (Three germ layers)

Question 15

What are the 3 layers of a gastrula?

Answer 15

Ectoderm
Endoderm
Mesoderm

Question 16

What is the ectoderm?

Answer 16

Integumentary, lens of eye, retina, and nervous system.

Question 17

What is the endoderm?

Answer 17

Epithelial linings of digestive and resp tracts, parts of the liver, pancreas thyroid and bladder.

Question 18

What is the mesoderm?

Answer 18

Musculoskeletal system, circulatory system, excretory system, connective issues, portions of digestive and resp organs.

Question 19

Where does embryo of a fish or amphibian develop?

Answer 19

In the egg that is laid in the water?

Question 20

What is a chorion in an egg?

Answer 20

Inside of the shell….membrane permitting gas exchange.

Question 21

What is the allantois in an egg?

Answer 21

Saclike structure used for respiration and excretion. Contains blood vessels to transport oxygen, CO2, water and salt and waste.

Question 22

What is the amnion in an egg?

Answer 22

Membrane enclosing amniotic fluid of an egg.

Question 23

What is amniotic fluid in an egg?

Answer 23

Aqueous environments that protects embryo from shock.

Question 24

What is the yolk sac in an egg?

Answer 24

Encloses the yolk. Transfer food to embryo.

Question 25

Marsupials develop in a placenta?

Answer 25

No. Neither do some tropical fish.

Question 26

How does has exchange occur in a fetus?

Answer 26

Across the placenta.

Question 27

Name the 4 extra-embryonic membranes formed during development:

Answer 27

Amnion Chorion Allantois Yolk sac

Question 28

What is the amnion in placental development?

Answer 28

Thin membrane containing amniotic fluid.

Question 29

What is the chorion in placental development?

Answer 29

Membrane completely surrounding amnion.

Question 30

What is the allantois in placental development?

Answer 30

Third membrane. Develops as an out pocketing of the gut.

Question 31

What does the umbilical cord develop from?

Answer 31

Enlarged blood vessels of the allantoic wall.

Question 32

What is the yolk sac in placental development?

Answer 32

Site of early development of blood vessels.

Question 33

3 stages of labor:

Answer 33

Cervix thins and dilates as amniotic sac ruptures. Rapid contractions Uterus contracts to expels the placenta and umbilical cord.

Question 34

What is different about arthropod and mammal maturation?

Answer 34

Arthropods are suspended in pupal stage. Mammals develop uninterrupted.

Question 35

What is the epicotyl?

Answer 35

Precursor of upper stem and leaves.

Question 36

What are the cotyledons?

Answer 36

Seed leaves. Dicots have two seed leaves and monocots only have one seed leaf.

Question 37

What is the hypocotyl?

Answer 37

Develops into the lower stem and root

Question 38

What is the endosperm?

Answer 38

Grows and feeds the embryo of a plants.

Question 39

What absorbs the endosperm in dicots?

Answer 39

Cotyledon

Question 40

What is the seed coat?

Answer 40

Develops from the outer covering of ovule.

Question 41

What is fruit formed from?

Answer 41

Ovary walls, the flower base and flower pistil

Question 42

What are meristem cells?

Answer 42

Undifferentiated cells in plants. Activate cell reproductions.

Question 43

What is the apical meristem?

Answer 43

Tips of rotor and stems. This is where growth in length occurs.

Question 44

What is the lateral meristem/cambium?

Answer 44

Between xylem and phloem. Permits growth in diameter.

Question 45

What kind of plants have an active lateral meristem/cambium?

Answer 45

Woody dicots like oaks. (not monocots like grass or herbaceous dicots like alfalfa)