Animal Development

Question 1

Preformation

Answer 1

concept of a miniature adult being present in the sperm or egg, waiting to unfold

Question 2

Epigenesis

Answer 2

concept that the fertilized egg contains building materials only, somehow assembled by an unknown directing force

Question 3

Development

Answer 3

series of progressive changes in an individual from its beginning to maturity

Begins when a fertilized egg divides mitotically

Question 4

Cell types arise from

Answer 4

conditions created in preceding stages

Question 5

Interactions become increasingly

Answer 5

restrictive

Question 6

Cells lose option to

Answer 6

become something different. Said to be determined

Question 7

The two basic processes responsible for progressive subsivision

Answer 7

cytoplasmic localization

induction

Question 8

Fertilization

Answer 8

initial event in development in sexual reproduction

Question 9

Fertilization provides for

Answer 9

recombination of paternal and maternal gametes-restores the diploid number

activates the egg to begin development

Question 10

Oocyte maturation

Answer 10

Egg grows in size by accumulating yolk

contains much mRNA, ribosomes, tRNA and elements for protein synthesis

Question 11

Morphogenetic determinants direct

Answer 11

the activation and repression of specific genes later in post fertilization development

Question 12

Germinal Vesicle

Answer 12

when the egg nucleus grows in size, bloated with RNA

Question 13

Contact and recognition between egg and sperm

Answer 13

marine organism

release enormous numbers of spam in the ocean to fertilize eggs

many eggs release chemotactic molecule

Question 14

chemotactic molecule

Answer 14

attract sperm of the same species

Question 15

Sea Urchin Sperm Fertilization

Answer 15

• penetrate a jelly layer surrounding egg.

- next contacts the vitelline envelope

Question 16

Vitelline Envelope

Answer 16

thin membrane above the egg plasma membrane

Question 17

Egg recognition proteins on the acrosomal process bind to

Answer 17

species specific sperm receptors on the vitelline envelope

Question 18

Prevention of Polyspermy

Answer 18

Fertilization cone forms where the sperm contacts the vitelline membrane

Question 19

Polyspermy

Answer 19

the entry of more than one sperm

Question 20

Fast block

Answer 20

In the sea urchin, an electrical potential rapidly spreads across the membrane

Question 21

Cortical reaction flows

Answer 21

• fusion of thousands of enzyme-rich cortical granules with the egg membrane
• cortical granules release contents between the membrane and vitelline envelope
• creates an osmotic gradient (one sperm has successfully fused with one egg plasma membrane)

Question 22

Fertilization membrane

Answer 22

vitelline envelope hardens

similar process occurs in mammals

Question 23

Diploid zygote nucleus

Answer 23

fusion of male and female nuclei

Question 24

Fertilized egg is called

Answer 24

zygote

Question 25

Inhibitors of metabolism that kept egg in quiescent state are

Answer 25

removed

Question 26

Fertilization iniriates

Answer 26

burst of DNA and protein synthesis using mRNA stored in the egg cytoplasm

Question 27

Repositions morphogenetic determinants activate or repress genes as

Answer 27

development proceeds

Question 28

Blastomeres

Answer 28

large cytoplasmic mass converted into small maneurvable cells

Question 29

In cleavage there is no _____, only subdivision until cells reach regular somatic cell size

Answer 29

cell growth

Question 30

At the end of the cleavage ____ is formed

Answer 30

blastula

Question 31

Isolecithal Eggs

Answer 31

very little yolk distributed evenly in cytoplasm cleavage is holoblastic (cleavage furrow extends completely through egg)

Question 32

Mesolecithal Eggs

Answer 32

moderate amount of gold concentrated in the vegetal pole

Question 33

Animal pole is the opposite of

Answer 33

vegetal pole

Question 34

Eggs cleave _______, but cleavage is slowed in yolk- rick vegetal pole

Answer 34

holoblastically

Question 35

Telolecithal Eggs

Answer 35

much yolk concentrated at vegetal pole cleavage is meroblastic

Question 36

Nuclear Equivalence

Answer 36

Roux-Weismann Hypothesis Genome gradually broken in smaller and smaller units

Question 37

Hans Spemann

Answer 37

Disproved Roux-Weismann Hypothesis

Question 38

Cytoplasmic Specification

Answer 38

- cytoplasmic components are unevenly distributed in a zygote - different components contain morphogenetic determinants that control commitment to cell type - different determinants are partitioned among different blastomeres by cleavage and determine cell fate

Question 39

Embryonic Induction

Answer 39

capacity of some cells to evoke a specific developmental response in other cells

Question 40

After fertilization

Answer 40

proteins are translated from stored mRNA transcribed from maternal genome

Question 41

In many animals, maternal mRNA directs protein synthesis through

Answer 41

cleavage and to mid-blastula stage

Question 42

Protein synthesis then switches from maternal to ____ as the nucleus transcribes its own mRNA

Answer 42

zygotic control

Question 43

In reptiles, birds, and mammals...embroys develop within the ________.

Answer 43

amnion

Question 44

Amniotic egg contains ________ including the amnion

Answer 44

4 extra embryonic membranes

Question 45

In the shelled amniotic egg

Answer 45

Yolk sac | Allantois

Question 46

Yolk sac

Answer 46

pre-dates the amniotes by millions of years | -stores yolk

Question 47

Allantois

Answer 47

storage of metabolic wastes during development contributes to formation of umbilical cord

Question 48

Chorion

Answer 48

- Lies beneath the egg shell - encloses the embryo and other extra embryonic membrane - As membrane grow - ---need for oxygen increases - ---allantois and chorion fuse to form a respiratory surface, the chorioallantoic membrane - evolution of the shelled amniotic egg made internal fertilization a requirement

Question 49

The Mammalian Placenta and Early Mammalian Development

Answer 49

most mammalian embryos do not develop within an egg shell - develop within the mother's body - most retained in the mother's body

Question 50

Monotremes

Answer 50

- lay eggs | - duck billed platypus and spiny anteater

Question 51

Marsupials

Answer 51

continue development in abdominal pouch of mother

Question 52

Placental Mammals

Answer 52

94% of Mammalia class - reconstruction of extra embryonic membranes - expanded region formed a uterus

Question 53

Amnion

Answer 53

remains unchanged surrounds embryo secretes fluid in which embryo floats

Question 54

Yolk sac

Answer 54

contains no yolk | source of stem cells that give rise to blood and lymphoid cells

Question 55

Chorion

Answer 55

forms most of the placenta