Development

Question 1

processes of development

Answer 1

1. cleavage
2. gastrulation
3. organogenesis

Question 2

development

Answer 2

a series of progressive changes in form and function that occurs during an organisms life cycle

Question 3

cleavage

Answer 3

division of cells to form blastula

Question 4

gastrulation

Answer 4

formation of tissue layers and axis; the blastula is transformed into an embryo with 3 tissue layers and body axes

Question 5

organogenesis

Answer 5

formation of organs

Question 6

morphogenesis

Answer 6

cell differentiation and growth to form the complex adult shape

Question 7

animal hemisphere

Answer 7

contains nucleus of the egg

Question 8

where nutrients accumulate

Answer 8

the vegetal hemisphere

Question 9

3 patterns of cleavage

Answer 9

1. complete
2. incomplete-discoidal
3. incomplete-superficial

Question 10

effect of mitotic spindles on cleavage pattern: 3 types

Answer 10

radial cleavage, spiral cleavage, rotational cleavage

Question 11

radial cleavage

Answer 11

spindles form at right angles/parallel to animal-vegetal axis

Question 12

spiral cleavage

Answer 12

spindles at oblique/diagonal angles to animal-vegetal axis

Question 13

rotational cleavage

Answer 13

first division is parallel to animal-vegetal axis, second division is at right angles

Question 14

at determination

Answer 14

the cells fate becomes fixed

Question 15

endoderm (inner layer)

Answer 15

digestive, respiratory and circulatory tracts

Question 16

ectoderm (outer layer)

Answer 16

epidermis and nervous system

Question 17

mesoderm (middle layer)

Answer 17

bone, muscle, liver, heart, and blood vessels

Question 18

blastodisc

Answer 18

the embryo-forming part of an egg - discoidal cleavage

Question 19

epiblast

Answer 19

embryo

Question 20

hypoblast

Answer 20

extraembryonic membranes

Question 21

blastula

Answer 21

an animal embryo at the early stage of development when it is a hollow ball of cells

Question 22

neurulation

Answer 22

occurs early in organogenesis and begins the formation of the nervous system in vertebrates

Question 23

somites

Answer 23

produce the vertebrae, ribs, and muscles of the trunk and limbs

Question 24

neural crest cells produce…

Answer 24

peripheral nerves

Question 25

development is controlled by

Answer 25

the cytoplasm, genes, external environment

Question 26

genomic activation

Answer 26

transmission from maternal control to embryo control

Question 27

cytoplasmic segregation

Answer 27

a factor is unequally distributed in the cytoplasm and ends up in some daughter cells but not others

Question 28

induction

Answer 28

a factor is secreted by some cells to induce other cells to differentiate

Question 29

a signal is considered to be a morphogen if...

Answer 29

1. it directly affects target cells | 2. different concentrations cause different effects

Question 30

genomic imprinting

Answer 30

some development genes are active only if they come from a sperm, others if they come from an egg

Question 31

types of segmentation genes

Answer 31

1. gap genes 2. pair rule genes 3. segment polarity genes 4. homeotic genes

Question 32

gap genes

Answer 32

organise large areas along the anterior-posterior axis

Question 33

pair rule genes

Answer 33

divide the embryo into units of 2 segments each

Question 34

segment polarity genes

Answer 34

determine segment boundaries

Question 35

homeotic genes

Answer 35

expressed along the length of the body and determine what the segments will become

Question 36

apoptosis

Answer 36

programmed cell death, caused by the activation of death genes

Question 37

clone

Answer 37

an individual that is genetically identical to another individual

Question 38

4 mechanisms of cloning

Answer 38

1. natural - asexual reproduction 2. embryo splitting - an early stage embryo is split into two or more genetically identical embryos 3. reprogramming somatic cells 4. nuclear transfer - removing the DNA from an oocyte (unfertilised egg), and injecting the nucleus which contains the DNA

Question 39

somatic cell

Answer 39

any cell of a living organism other than reproductive cells

Question 40

potential uses of cloning

Answer 40

- elite livestock - disease resistant farming - developmental research, clones used as controls - conservation

Question 41

phenotype of an adult organism results from ...

Answer 41

interaction of genes, gene products, and environment

Question 42

morphological changes result from:

Answer 42

1. mutations in the genes that regulate development 2. changes in the spatial expression of developmental genes 3. changes in temporal expression of developmental genes

Question 43

gremlin

Answer 43

BMP inhibitor in ducks which prevents BMP4 apoptosis of webbed feet