Ch 47

Question 1

When does a human embryo begin to show distinctive features?

Answer 1

5 week

Question 2

Order of embryonic development (frog) (6)

Answer 2

Zygote
Blastula
Gastrula
Tail-bud embryo (frog)
Larval Stage
Adult

Question 3

What is the definition for Fertilization?

Answer 3

Formation of diploid zygote from haploid egg and sperm

Question 4

Sperm ____ the protective layer around the egg

Answer 4

Penetrate

Question 5

What binds to the molecules on the sperm surface?

Answer 5

Receptors on egg surface

Question 6

What is Polyspermy?

Answer 6

The entry of multiple sperm nuclei into the egg

Question 7

What prevents polyspermy

Answer 7

Changes at egg surface

Question 8

What is triggered when the sperm meets the Egg?

Answer 8

Acrosomal Reaction

Question 9

What releases hydrolytic enzyme that digest material surround the egg?

Answer 9

Acrosome

Question 10

What causes fast block to polyspermy

Answer 10

Gamete contact depolarizes the egg cell membrane and causes the blockage

Question 11

Fusion of egg and sperm initiate which reaction? What does it form?

Answer 11

Cortical Reaction
Forms fertilization envelope

Question 12

What does the fertilization envelope act as

Answer 12

Slow block to polyspermy

Question 13

Cortical reaction requires?

Answer 13

High concentration of calcium ion in the egg

Question 14

What is cortical reaction caused by?

Answer 14

Change in Ca concentration
Spread of Ca correlates with appearance of the fertilization envelope

Question 15

The rise of Ca in cytosol cause increase of what?

Answer 15

Cellular respiration and protein synthesis by the egg cell

Question 16

When is an egg activated?

Answer 16

With rapid changes of metabolism (inc cell respiration and protein synthesis)

Question 17

Where are proteins and mRNA needed for activation come from?

Answer 17

Already present in the egg

Question 18

Because humans have internal fertilization, sperm must travel through ______ to get to the zone of pellucida

Answer 18

follicle cells

Question 19

Sperm must travel through a layer of follicle cells surrounding the egg to reach?

Answer 19

The zone pellucida
extracellular matrix of egg

Question 20

Sperm binding triggers?

Answer 20

Cortical Reaction

Question 21

Time in mammals for the first cell division?

Answer 21

12-36 hours

Question 22

What follows after fertilization?

Answer 22

Cleavage: period of rapid cell division without growth

Question 23

Cleavage partitions the cytoplasm of one large cell into many smaller cells called?

Answer 23

Blastomeres

Question 24

Ball of cells

Answer 24

Blastula

Question 25

Blastula fluid filled cavity

Answer 25

Blastocoel

Question 26

Why is cleavage asymmetric in frogs?

Answer 26

Due to distribution of yolk

Question 27

Which pole has more yolk?

Answer 27

Vegetal pole

Question 28

Which pole has less yolk?

Answer 28

Animal pole

Question 29

The first two cleavage furrows in the frog form?

Answer 29

4 equal blastomeres

Question 30

What is the third cleavage in a frog like

Answer 30

Forms unequal blastomeres due to yolk in vegetal hemisphere

Question 31

Complete division of the egg and occurs in species with little/moderate amount of yolk?

Answer 31

Holoblastic Cleavage

Question 32

Incomplete Division of the egg and occurs in species with lots of yolk?

Answer 32

Meroblastic cleavage

Question 33

Morphogenesis

Answer 33

The process by which cells occupy their appropriate locations Gastrulation Organogensis

Question 34

The movement of cells from the blastula surface to the interior of the embryo

Answer 34

Gastrulation

Question 35

The formation of organs

Answer 35

Organogenesis

Question 36

Gastrulation

Answer 36

Rearranges the cells of a blastula into a three layered embryo called a gastrula

Question 37

Gastrula

Answer 37

3 layered embyro

Question 38

Three layers produced by gastrulation?

Answer 38

Germ layers

Question 39

Ectoderm

Answer 39

outer layer

Question 40

Endoderm

Answer 40

Digestive tract

Question 41

Mesoderm

Answer 41

Fill the space between endoderm and ectoderm

Question 42

Which germ layer gives rise to the epidermis

Answer 42

ectoderm

Question 43

Which germ layer gives rise to the nervous system and sensory system

Answer 43

ectoderm

Question 44

Which germ layer gives rise to the pituitary gland

Answer 44

ectoderm

Question 45

Which germ layer gives rise to the adrenal medulla

Answer 45

ectoderm

Question 46

Which germ layer gives rise to the jaws and teeth

Answer 46

ectoderm

Question 47

Which germ layer gives rise to the skeletal and muscular systems

Answer 47

mesoderm

Question 48

Which germ layer gives rise to the circulatory and lymphatic systems

Answer 48

mesoderm

Question 49

Which germ layer gives rise to the excretory and reproductive systems

Answer 49

mesoderm

Question 50

Which germ layer gives rise to the dermis of the skin

Answer 50

mesoderm

Question 51

Which germ layer gives rise to the adrenal cortex

Answer 51

mesoderm

Question 52

Which germ layer gives rise to the epithelial lining of digestive tract and associated organs

Answer 52

endoderm

Question 53

Which germ layer gives rise to the epithelial lining of respiratory, excretory, and reproductive tracts and ducts

Answer 53

endoderm

Question 54

Which germ layer gives rise to the thymus, thyroid, and parathyroid glands

Answer 54

endoderm

Question 55

How does frog gastrulation begin?

Answer 55

Begins when a group of cells on DORSAL side of Blastula begin to invaginate

Question 56

Frog gastrulation process

Answer 56

1) cells move from embryo surface into embryo by involution 2) Becomes endo and mesoderm 3) Cells on embryo surface will form the ectoderm 4) New cavity is called the Archenteron 5) This opens through the blastopore which will become the anus

Question 57

Prior to gastrulation in chicks the embryo is composed of?

Answer 57

Upper/lower layer epiblast hypoblast

Question 58

Where do the epiblast cells move during gastrulation

Answer 58

Move toward the midline of the blastoderm and then into embryo towards the yolk

Question 59

Midline thickening forms what?

Answer 59

Primitive streak

Question 60

Hypoblast role in chick gastrulation

Answer 60

Contribute to the sac that surround the yolk and connection between yolk and embryo

Question 61

Human equivalent of the blastula

Answer 61

Blastocyst

Question 62

Cluster of cells at one end of bastocyst

Answer 62

Inner cell mass

Question 63

Outer epithelial layer of the blastocyst and initiates implantation

Answer 63

trophoblast

Question 64

Trophoblast continues to expand what is formed?

Answer 64

Extraembryonic membranes

Question 65

Gastrulation in humans is similar to chick embryo how?

Answer 65

It involves inward movement from epiblast through a primitive streak

Question 66

Four extra embryonic membranes?

Answer 66

Chorion, Allantois, amnion, Yolk sac Provide life support system for embryo

Question 67

Reproduction out of aqueous environments require?

Answer 67

Shelled eggs or Uterus

Question 68

Embryos are surrounded by fluid in a sac called?

Answer 68

Amnion Allows reproduction on dry land

Question 69

Functions in gas exchange

Answer 69

Chorion

Question 70

Encloses the amniotic fluid

Answer 70

Amnion

Question 71

Encloses the yolk

Answer 71

Yolk sac

Question 72

Disposes of waste products and contributes to gas exchange

Answer 72

Allantois

Question 73

What process begins the formation of brain and spinal cord?

Answer 73

Neurulation

Question 74

How does neurulation begin?

Answer 74

Cells from dorsal mesoderm form the notochord

Question 75

What forms the neural plate?

Answer 75

Signaling molecules secreted by the notochord and other tissues cause the ectoderm above to form neural plate

Question 76

When cells or tissues cause a developmental change in nearby cells?

Answer 76

Induction

Question 77

Neural plate curves inward forming the _______?

Answer 77

Creates neural tube Will become central nervous system

Question 78

What happens to the notochord?

Answer 78

Disappears before birth but helps contributes to parts of the disks between vertebrae

Question 79

Where do the neural crest cells develop and migrate along?

Answer 79

It develops along the neural tube of vertebrates and migrate in the body

Question 80

What does the mesoderm form lateral to the notochord

Answer 80

Somites

Question 81

What do Somites form?

Answer 81

Form mesenchyme cells form vertebrae, ribs, and muscles

Question 82

Organogenesis in Chick

Answer 82

Similar to frog By the time embryo is 3 days old most rudiments of the major egg are apparent

Question 83

Whats required to help cause cell shape changes or cause a cell to migrate to a new location?

Answer 83

Microtubules and microfilaments of the cytoskeleton are essential to these events

Question 84

What is the major force in changing cell shape?

Answer 84

Reorganizing the cytoskeleton

Question 85

How do cells become wedge shaped

Answer 85

Contraction of actin filaments at the apical end of cells

Question 86

4 examples of Apoptosis

Answer 86

1) tail of tadpoles 2) used to eliminate extra neurons 3) Formation of ventricles of the brain and heart 4) Apoptosis of tissue between digits

Question 87

Resulting specialization in structure and function

Answer 87

Differentitation

Question 88

Process by which a cell becomes committed to particular fate

Answer 88

Determination

Question 89

Cells in multicellular organism share?

Answer 89

The same genome

Question 90

How are differences in cell types caused?

Answer 90

Result of the expression of different sets of genes