Mammals Flashcards
What is the main adaptation of mammals to extreme cold?
To retain body heat and maintain body temperature (core temp)
Examples include thick fur, fat layers, and behavioral adaptations like hibernation.
What is the primary adaptation of mammals to extreme heat?
To limit water loss and maximize ingested water
This includes adaptations such as efficient kidneys and behavioral changes.
What is the purpose of the Loop of Henle in mammalian kidneys?
To enable reabsorption of water and produce concentrated urine
A longer Loop of Henle is an adaptation for water retention.
What is glomerular filtration?
The process where blood passes through a biological microfilter in the kidney (glomerulus)
Smaller molecules like salts and water pass through, while larger molecules and blood cells do not.
What adaptations do mammals have to prevent water loss?
Adaptations include:
* Rarely sweating
* Large surface area:volume ratio
* Thick fur
* Fat storage (e.g., hump in camels)
* Special features like double row of eyelashes and slit-like nostrils.
What adaptations do marine mammals have for low oxygen environments?
Adaptations include:
* Efficient air exchange at the surface
* Increased oxygen uptake in blood
* Reduced blood supply to extremities
* Slow heart rate.
What is the role of haemoglobin (Hb) in mammals?
Oxygen transport and gas exchange
Hb binds up to 4 oxygen molecules cooperatively.
What is the oxygen-Hb dissociation curve?
A sigmoidal curve representing the relationship between blood PO2 and % Hb saturation
High PO2 increases Hb saturation, while low PO2 decreases it.
What distinguishes placentals from marsupials?
Placentals develop their embryos in the uterus with a placenta, while marsupials have a pouch for undeveloped young
Examples of placentals include humans, while kangaroos are marsupials.
What physiological response occurs in humans during extreme heat?
Sweating is the primary method of cooling
Humans can lose up to 12 liters of liquid on very hot days.
What is the definition of ‘viviparous’?
Organisms that give birth to live young
In contrast to oviparous organisms that lay eggs.
What are monotremes?
Egg-laying mammals
Examples include the duck-billed platypus and spiny anteaters.
What is the physiological state of hibernation?
A state of winter dormancy involving a significant slowdown of metabolism
It can last for months and is regulated by environmental conditions.
What is the significance of circadian rhythms?
They are physiological and behavioral characteristics that follow a daily pattern
Examples include sleep-wake cycles and hormone secretion.
What adaptation do diving mammals have to prevent the bends?
A flexible rib cage that allows their lungs to collapse during deep dives
This prevents nitrogen absorption and reduces the risk of decompression sickness.
What is myoglobin (Mb)?
An oxygen-storing protein found in muscle tissues
It facilitates O2 diffusion in contracting muscles.
What is the primary adaptation of polar bears to extreme cold?
Insulating layers of thick fur and fat
This minimizes heat loss and aids in thermoregulation.
What are the three main classifications of mammals based on reproduction?
Monotremes, marsupials, and placentals
Each classification has distinct developmental characteristics.
What is the effect of increased CO2 on the oxygen-Hb dissociation curve?
It shifts the curve to the right
This indicates that Hb releases oxygen more readily.
