Chapter 8

Question 1

Which gamete can contribute either and X or a Y

Answer 1

sperm

Question 2

T/F Y chromosomes have a fraction of the genes compared to X chromosomes

Answer 2

True

Question 3

SRY gene

Answer 3

a gene present of the Y chromosome which determines the sex of a human

Question 4

What happens if the SRY gene is deleted?

Answer 4

XY fetuses develop female reproductive systems

Question 5

What system develops and which degenerates in fetuses with SRY genes?

Answer 5

Wolffian system develops and Mullerian system degenerates

Question 6

what is are the primordial reproductive systems?

Answer 6

Wolffian - male
Mullerian - female

Question 7

T/F mammals have genotypic sex determination

Answer 7

True

Question 8

What is the timeline for the zygote stage

Answer 8

0-2 weeks

Question 9

what is the timeline of the embryonic stage

Answer 9

2-8 weeks

Question 10

T/F there are large differences between vertebrates in the embryonic stage

Answer 10

F - they look alike as embryos and develop more distinct forms as they grow

Question 11

What are the organizer tissue layers and what do they develop into?

Answer 11

Ectoderm - skin
Mesoderm - muscles and bone
Endoderm - digestive and respiratory

Question 12

what is the first stage of nervous system development

Answer 12

neural plate stage in embryo

Question 13

what is the second stage of nervous system development

Answer 13

neural tube stage, where the plate folds and forms a tube

Question 14

what protects the nervous system during development

Answer 14

skin and bone encasement

Question 15

what does the hollowed area of the neural tube become

Answer 15

the ventricles

Question 16

Where does the peripheral nervous system develop from

Answer 16

neural crest

Question 17

What are of the nervous system serves as a nursery for the rest of the developing CNS

Answer 17

neural tube

Question 18

spina bifida

Answer 18

failure of the neural tube to close completely leaving a portion of the spinal cord uncovered

Question 19

how is spina bifida fixed?

Answer 19

through surgery, though may result in paralysis

Question 20

anencephaly

Answer 20

front end of the neural tube does not close leading to lack of forebrain development

Question 21

how is anencephaly fixed

Answer 21

it is not fixable, will be fatal

Question 22

when does fetal heart beat begin

Answer 22

35 days

Question 23

where does stem cell proliferation occur

Answer 23

sub ventricular zone

Question 24

what does it mean to say that stem cells are totipotent

Answer 24

they have the ability to become any kind of cell

Question 25

what are the two daughter cells that are created by a dividing stem cell

Answer 25

one that is another stem cell one that becomes what it needs to be

Question 26

Subventricular zone

Answer 26

lining of neural stem cells surrounding the ventricles

Question 27

progenitor cells

Answer 27

early version of a nervous system cell created from a stem cell

Question 28

what can progenitors become?

Answer 28

neuroblasts (baby neurons) or glioblasts (baby glial cells)

Question 29

T/F progenitor cells migrate out of the subventricular zone into their spot of the developing brain

Answer 29

F - progenitor cells develop into blasts before migrating

Question 30

what are the two types of cell migration

Answer 30

radial and tangential

Question 31

how many layers are in the neocortex

Answer 31

6 layers, with layer 6 being the deepest

Question 32

which layer of the neocortex is developed first?

Answer 32

the 6th layer

Question 33

what cell is responsible for radial migration

Answer 33

radial glial cells present during development

Question 34

how do radial glial cell cause migration

Answer 34

they radiate out like spokes and developing cells move along the cell to their spot

Question 35

what protein is responsible for tangential migration

Answer 35

reelin chemical signals

Question 36

T/F after migration and aggregation, blasts develop into specific nervous system cells

Answer 36

true

Question 37

why to neural cells aggregate

Answer 37

because they need to be near each other to make connections

Question 38

how does cell differentiation occur

Answer 38

chemical signals activate specific genes which create proteins for specific cells

Question 39

T/F cell differentiation is complete by birth

Answer 39

true

Question 40

what are the two ways that neurons mature

Answer 40

axonal growth to nearby targets for synapse formation dendritic growth to provide surface are of synapses

Question 41

T/F dendritic growth occurs much faster than axon growth

Answer 41

F - axons much faster

Question 42

growth cones

Answer 42

early axon terminals that support axon growth

Question 43

filopod

Answer 43

sprouts from axon that search for potential synapses

Question 44

synaptogenesis

Answer 44

creation of synapses between developed neurons

Question 45

when can synaptogenesis occur

Answer 45

when neurons are developed

Question 46

what leads growth cones and fasciculation

Answer 46

chemical signalling

Question 47

fasciculation

Answer 47

creating synapses with a purpose

Question 48

synaptic rearrangement

Answer 48

synaptic patterns become more focused later throughout to development

Question 49

when do gyri and sulci begin to develop

Answer 49

8 months

Question 50

what are the 2 types of cell death

Answer 50

necrosis and apoptosis

Question 51

necrosis

Answer 51

cell dies and contents spill out, which can damage other nearby cells

Question 52

apoptosis

Answer 52

controlled self-destruction

Question 53

T/F Cell death is a necessary part of normal development

Answer 53

T

Question 54

T/F Neuronal maturation slows after birth

Answer 54

F - continues through life

Question 55

T/F Neurogenesis is mostly complete by birth

Answer 55

T

Question 56

what determines the postnatal development of the brain

Answer 56

exposure

Question 57

when does myelination occur

Answer 57

after the baby is born and continue through life

Question 58

what are the main areas of brain development in babies

Answer 58

primary visual and auditory cortices

Question 59

what area of the brain lags behind during development, as it tends to develop last

Answer 59

the prefrontal cortex

Question 60

T/F Synaptogenesis spikes after birth, then pruning begins in first year and synapses decrease

Answer 60

True

Question 61

Neural Darwinism

Answer 61

survival of useful synapses only as too many synapses will waste nutrition