Ch 47 Animal Development

Question 0

Three steps of fertilization

Answer 0

1) Sperm penetrate the protective layer around the egg
2) Receptors on the egg surface bind to molecules on the sperm surface
3) Changes at the egg surface prevent polyspermy

Question 1

Development occurs when during the life cycle of an animal?

Answer 1

At many points

Question 2

Polyspermy

Answer 2

The entry of multiple sperm nuclei into the egg

Question 3

In sea urchins, what is triggered when the sperm meets the egg?

Answer 3

An acrosomal reaction

Question 4

Acrosome

Answer 4

A substance at the tip of sea urchin sperm that releases hydrolytic enzymes that digest that digest material surrounding the egg

Question 5

The acrosomal process binds to what?

Answer 5

Receptors in the egg in a lock-and-key fashion

Question 6

Gamete contact and/or fusions serves what two purposes?

Answer 6

1) Depolarizes the egg cell membrane

2) Sets up a fast block to polyspermy

Question 7

Cortical reaction

Answer 7

A reaction where vesicles beneath the egg plasma membrane release their contents and form and fertilization envelope that acts as a slow block to
polyspermy

Question 8

Calcium ion released in the cortical reaction activates what?

Answer 8

The egg to increase respiration and protein synthesis

The nuclei of the sperm and egg merge

Question 9

Fertilization in mammals and other terrestrial animals is internal or external?

Answer 9

Internal

Question 10

Capacitation

Answer 10

Secretions in the mammalian female productive tract alter sperm motility and structure

Question 11

What must occur before sperm are able to fertilize an egg?

Answer 11

Capacitation

Question 12

Is a form of fast block to polyspermy known in mammals?

Answer 12

No.

Question 13

What triggers a slow block to polyspermy in mammals?

Answer 13

Sperm binding a receptor in the extracellular so a pellucida

Question 14

Blastomeres

Answer 14

Smaller cells formed by cleavage

Question 15

Blastula

Answer 15

A ball of cells with a blastocoel

Question 16

Blastocoel

Answer 16

Fluid-filled cavity of the blastula

Question 17

In frogs and many other animals, what influences the pattern of cleavage?

Answer 17

The distribution of yolk

Question 18

The difference in yolk distribution results in what?

Answer 18

Animal and vegetal hemispheres that differ in appearance

Question 19

Vegetal pole has more or less yolk?

Answer 19

More

Question 20

Animal pole has more or less yolk?

Answer 20

Less

Question 21

Holoblastic cleavage

Answer 21

Complete division of the egg

Question 22

Holoblastic cleavage occurs in what species?

Answer 22

Species whose eggs have little or moderate amounts if yolk

Ex: Sea urchins and frogs

Question 23

Meroblastic cleavage

Answer 23

Incomplete division of the eggs

Question 24

Meroblastic cleavage occurs in what species?

Answer 24

Species with yolk-rich eggs Ex: Reptiles and birds

Question 25

Morphogenesis

Answer 25

The process by which cells occupy their appropriate locations

Question 26

Morphogenesis involves what two things?

Answer 26

1) Gastrulation | 2) Organogenesis

Question 27

Gastrulation

Answer 27

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

Question 28

Germ layers

Answer 28

The three layers produces by gastrulation

Question 29

Ectoderm (definition)

Answer 29

Forms the outermost germ layer

Question 30

Endoderm (definition)

Answer 30

Lines the digestive tract

Question 31

Mesoderm (definition)

Answer 31

Partly fills the space between the endoderm and ectoderm

Question 32

Each germ layer contributes to what?

Answer 32

Specific structures in the adult animal

Question 33

The ectoderm gives rise to what?

Answer 33

1) Epidermis of skin and its derivatives (sweat glands, hair follicles) 2) Nervous and sensory systems 3) Pituitary gland, adrenal medulla 4) Jaws and teeth 5) Germ cells

Question 34

The mesoderm gives rise to what?

Answer 34

1) Skeletal and muscular systems 2) Circulatory and lymphatic systems 3) Excretory and reproductive systems 4) Dermis if skin 5) Adrenal cortex

Question 35

The endoderm gives rise to what?

Answer 35

1) Epithelial lining if digestive tract and associated organs 2) Epithelial lining if respiratory, excretory, and reproductive tracts 3) Thymus, thyroid, and parathyroid

Question 36

How much yolk do human eggs have?

Answer 36

Very little

Question 37

Blastocyst

Answer 37

Human equivalent of the blastula

Question 38

Topholblast

Answer 38

The outer epithelial layer of the blastocyst

Question 39

Does the trophoblast contribute to the embryo?

Answer 39

No

Question 40

What does the trophoblast initiate?

Answer 40

Implantation

Question 41

What occurs to the trophoblast following implantation?

Answer 41

It continues to expand and a set of extraembryonic membranes is formed

Question 42

Organogenesis

Answer 42

Process during which various regions of the germ layers develop into rudimentary organs

Question 43

What two structures form early in vertebrate ogranogenesis?

Answer 43

1) Notochord forms from mesoderm | 2) Neural plate forms from ectoderm

Question 44

Mesoderm lateral to the notochord forms what?

Answer 44

Somites

Question 45

Somites

Answer 45

Blocks of mesoderm

Question 46

What occurs laterally to somites?

Answer 46

The mesoderm splits to form the coelom

Question 47

During organogenesis, what changes cell shape and position?

Answer 47

Reorganization of the cytoskeleton

Question 48

Apoptosis

Answer 48

Programmed cell death

Question 49

At various times during development, what happens to indvidual cells, sets of cells, or whole tissues?

Answer 49

They stop growing and are engulfed by neighboring cells

Question 50

Determination

Answer 50

Describes the process by which a cell or group of cells becomes committed to a particular fate

Question 51

Differentiation

Answer 51

Refers to the specialization in structure and function resulting from determination

Question 52

Fate maps

Answer 52

Describe cell differentiation by showing what structures arise from each region

Question 53

What helps establish the anterior-posterior axis in animals such as chicks?

Answer 53

Gravity

Question 54

What helps establish the dorsal-ventral axis?

Answer 54

pH differences between the two sides of the blastoderm

Question 55

In mammals, what may help establish embryonic axis?

Answer 55

Orientation of the egg and sperm nuclei before fusion

Question 56

Inductive signals play a major role in what?

Answer 56

Pattern formation

Question 57

Pattern formation

Answer 57

Development of spatial organization

Question 58

Positional information

Answer 58

Molecular cues that control pattern formation

Question 59

What tells a cell where it is with respect to the body axes?

Answer 59

Positional information

Question 60

In the human embryo, ciliary function is essential for what?

Answer 60

Proper specification of cell fate in the human embryo

Question 61

Monocilia (nonmotile cilia)

Answer 61

Plays roles in normal kidney development in human embryo

Question 62

Motile cilia

Answer 62

Play roles in left-right specification in human embryo