Exam 1: Chapter 4: Physiological Development and Epigenetics Flashcards
Hooded seals
- 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
Hooded seals (oxygen)
- 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
Underdeveloped muscles in hooded seals causes:
less myoglobin to be present, allowing for less oxygen storage which results in shorter dive times
How long do young hooded seals dive compared to adults?
young: 2 to 5 mins each time, 14 short dives/hr
adult: 5 to 25 mins each time, 4 dives/her
How are young hood seal dives different from adults?
dive shallowed distances with limited hunting success
Young hooded seals must succeed to…
become a reproductive adult
Young hood seals spend how much of their time underwater feeding?
90%
How does the physiology of immature animals differ from that of an adult?
- 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
How does lab rat physiology different from other mammals?
reproductive organs mature before the brain to ensure reproduction takes place (adaptation)
How much energy does the brain use?
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.
What is needed in children for proper brain development?
adequate food and nutrition
How do males and females different in development?
males and females mature reproductively at different rates
homeothermy
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
Thermoregulation in mice:
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
what happens to enzymes during tissue development
enzymes are upregulated; can have an effect on cell metabolism
Early fetal rats can’t synthesize _________ due to _______.
liver glycogen; lack of glycogen synthase
Production of glycogen synthase in rats begins…
5 days after birth; newborn rats can then synthesize liver glycogen
3 waves of gene expression
right before birth, at birth, after birth
each wave is upregulated differently
how are mRNAs regulated during development?
sequentially
some are coded for enzymes shown previously
different sets of genes are transcribed…..
at different times during development
Phenotype plasticity:
an animals phenotype is changeable; common in development
Different environments can cause
phenotype plasticity
How has menarche changed?
occurs earlier now than in the past; changed due to improved nutrition, public health, and medical care
Give an exam of how height can be show phenotypic plasticity
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
