Queetions Corrections 2019 Flashcards
Describe transport of water through a plant from the roots to the atmosphere
Water is transported in xylem
Water evaporates from leaves
Through the stomata
Suggest one reason why a plant had a high rate of water loss
Plant had more leaves
Suggest two reasons why rate of water loss suddenly increases
It was warmer
Light intensity was higher
Mechanical heart valves or biological replacement heart valves
Both valves readily available and little wait time
Mechanical valves are longer lasting, blood clots are more likely, anticlotting medication must be taken
Some patients say they can hear valves opening and closing
Biological valves have ethical issues surrounding use of animal tissue, valve may harden, more likely to need immuno suppressants
Explain how diabetes can cause the body to lose more water
Blood is more concentrated
So water moves out of the cells by osmosis
Through a partially permeable membrane
Describe how the small intestine is adapted for efficient absorption
Villi provide large surface area
Walls of capillaries are one cell thick so shorter diffusion distance
Small intestine has efficient blood supply to maintain concentration gradient
Many mitochondria for respiration for active transport
Small intestine very long increasing absorption time
What is a double circulatory system
Blood is pumped to lungs by one side of the heart
And blood is pumped to body by the other side of the heart
Why does having only one ventricle make circulatory system less efficient
Oxygenated and deoxygenated blood mixes
So less oxygen reaches the body
Explain why an axolotl may die in water with a low concentration of oxygen
Concentration gradient is less steep
So less oxygen diffuses into blood
So less aerobic respiration occurs so less energy is released
So less metabolism
Explain how pancreatic cancer may cause a person to lose weight
Reduced enzyme production
So food is not broken down fully
So less glucose is absorbed into the blood stream
