Exam 1: Chapter 4: Physiological Development and Epigenetics

Question 1

Hooded seals

Answer 1

• mothers give birth on sheet of ice
• nurse for 3 days
• remain on ice, must look for own food
• ability to dive is really important

Question 2

Hooded seals (oxygen)

Answer 2

• ability to store O2 is important for diving
• oxygen is stored in tissues of the animal
• oxygen is stored in the lungs
• oxygen is stored in blood attatched to hemoglobin
• oxygen attatched to myoglobin is used to swim

Question 3

Underdeveloped muscles in hooded seals causes:

Answer 3

less myoglobin to be present, allowing for less oxygen storage which results in shorter dive times

Question 4

How long do young hooded seals dive compared to adults?

Answer 4

young: 2 to 5 mins each time, 14 short dives/hr
adult: 5 to 25 mins each time, 4 dives/her

Question 5

How are young hood seal dives different from adults?

Answer 5

dive shallowed distances with limited hunting success

Question 6

Young hooded seals must succeed to…

Answer 6

become a reproductive adult

Question 7

Young hood seals spend how much of their time underwater feeding?

Answer 7

90%

Question 8

How does the physiology of immature animals differ from that of an adult?

Answer 8

• tissues and organs develop at different rates
• brain isn’t mature until about 7 years
• general body tissues are about half that
• mammals tend to push things off until after birth

Question 9

How does lab rat physiology different from other mammals?

Answer 9

reproductive organs mature before the brain to ensure reproduction takes place (adaptation)

Question 10

How much energy does the brain use?

Answer 10

In adults, the brain is 20% of the metabolic rate, even through it takes up about 2% of body mass.
At the age of 4-5, 50% of a childs metabolism goes to brain development (half the food they eat); starvation at this age has greater effects on the brain.

Question 11

What is needed in children for proper brain development?

Answer 11

adequate food and nutrition

Question 12

How do males and females different in development?

Answer 12

males and females mature reproductively at different rates

Question 13

homeothermy

Answer 13

having a relatively uniform body temperature maintained nearly independent of the environmental temperature; develops as animals age, depend on the warmth of the mother before they can thermoregulate

Question 14

Thermoregulation in mice:

Answer 14

not able to do so until about 3 weeks; over 3 week nesting time, they become adults, generate heat, grow fur, and resist heat loss

Question 15

what happens to enzymes during tissue development

Answer 15

enzymes are upregulated; can have an effect on cell metabolism

Question 16

Early fetal rats can’t synthesize _________ due to _______.

Answer 16

liver glycogen; lack of glycogen synthase

Question 17

Production of glycogen synthase in rats begins…

Answer 17

5 days after birth; newborn rats can then synthesize liver glycogen

Question 18

3 waves of gene expression

Answer 18

right before birth, at birth, after birth

each wave is upregulated differently

Question 19

how are mRNAs regulated during development?

Answer 19

sequentially

some are coded for enzymes shown previously

Question 20

different sets of genes are transcribed…..

Answer 20

at different times during development

Question 21

Phenotype plasticity:

Answer 21

an animals phenotype is changeable; common in development

Question 22

Different environments can cause

Answer 22

phenotype plasticity

Question 23

How has menarche changed?

Answer 23

occurs earlier now than in the past; changed due to improved nutrition, public health, and medical care

Question 24

Give an exam of how height can be show phenotypic plasticity

Answer 24

British factory children and those in a medieval village were shorter than recent children; harsh living conditions and improper nutrition are thought to be responsible

Question 25

epigenetics

Answer 25

changes to gene expression with no changes to the DNA sequence; passed down through generations

Question 26

how are epigenetic marks created?

Answer 26

by environmental events, attached to the DNA

Question 27

epigenetic can cause changes to…

Answer 27

gene expression; can be positive or negative

Question 28

CH3 epigenetic markers

Answer 28

methylate cytosines; DNA can’t be opened for transcription and replication

Question 29

how can methylation be passed on?

Answer 29

through mitosis; the methylation is replicated when the DNA is replicated during mitosis

Question 30

When epigenetic changes occur during embryonic development, it will be passed on….

Answer 30

to all cells of the organism

can then be passed to offspring

Question 31

example of negative epigenetic changes

Answer 31

changes caused by smoking and second hand smoke

Question 32

two types of epigenetic marks

Answer 32

DNA methylation and covalent modification of histone proteins

Question 33

what does cytosine methylation in DNA cause?

Answer 33

acts to silence gene expression

Question 34

methyltransferase

Answer 34

helps to retain the marks to the new generation during replication of DNA

Question 35

what can modify histone proteins?

Answer 35

methylation, acetylation, phosphorylation, and others

Question 36

methylome

Answer 36

all the methylated DNA locations

Question 37

epigenetic inheritance can be

Answer 37

individual or transgenerational

Question 38

during development when cells migrate to their target they begin to….

Answer 38

differentiate

Question 39

with terminal differentiation

Answer 39

cells gene expression is altered; each expressed a subset of their genes specific to their function

Question 40

malnutrition affect on methylation

Answer 40

causes reduced methylation;

example- malnutrition in the netherlands during WW2

Question 41

Effects of suffering malnutrition in early life

Answer 41

higher levels of gene expression as adults

shown to result in cardiovascular and metabolic disease later in life

Question 42

example of lifelong effects of early-life stress

Answer 42

studies have shown high rates of obesity and coronary artery disease

Question 43

intermediate in the methylation process

Answer 43

folic acid; lack of folic acid cases decreased sites of methylation

Question 44

methylation of oncogenes

Answer 44

results in less chance of cancer; without that cancer could result