Bits you forget Flashcards
What is a Hormone?
Chemical released into the bloodstream, that travels to a distant site and acts upon a target receptor to cause a particular physiological response
Where is insulin produced?
Pancreas
What does Insulin in the liver do?
Stimulates the liver to turn glucose into glycogen
Things you need to keep the same in the body?
Water, Ions, Blood Sugar, Temp c’ and pH levels
What is Homeostasis?
Maintainance of a constant internal environment
What happens to urine concentration and volume when your in a hot place or excercising?
Sweating more –> Losing More Water
Blood water levels will be lower
High ADH
Reabsorbs more water from urine
Urine Volume is much lower
What Happens when you are too hot?
Sweat –> Evaporates transferring heat energy from the skin to the environment
Vasodilation –> Blood vessles near the skin surface widen, allowing more blood flow to the surface of the skin. This allows more heat to be lost to the environment
Hairs Lie Flat
What happens when you’re too cold?
Very little sweat is produced
Vasoconstriction –> blood vessels near the surface of the skin constrict, reducing blood flow near the surface of the skin helping to reduce the amount of heat lost from the surface of the skin
Shiver –> Increases the rate of respiration because of increased muscle contraction and increased requirement of energy –> Heat energy warms the body
Piloerection –> Hairs stand up –> Trap heat to produce insulating layer around the skin
Do large animals have a high SA:V?
Low SA:V (SO NO)
Do large animals cool down slower or faster?
Cool down slower as they lose heat to surroundings at a slower rate
2 Responses to stimuli?
Geotropism
Phototropism
What are Auxins?
Plant hormones that control growth at the tips of shoots and roots
What is a Shoot’s response to light?
Positively Phototropic
When a shoot tip is exposed to light, it accumulates more auxins on the shaded side than the side in the light
This makes the cells grow (elongate) faster on the shaded side compared to the non-shaded side
This helps to bend the shoot towards the light
(Auxins promote growth in shoots)
What is a Roots response to light?
Negatively Phototropic
Auxins inhibit Growth
If a root starts being exposed to some light, more auxins accumulate on the more shaded side
The auxins inhibits cell elongation on the shaded side, so the root bends downwards back into the ground
Roots that are underground aren’t exposed to light, they grow downwards due to positive geotropism
What is a Chromosome?
Long lengths of DNA coiled up around proteins
Diploid?
Have 2 copies of each chromosome arranged in pairs