B1-B3 Paper Flashcards
Which part of the brain automatically controls heart rate and breathing rate?
Medulla
Which hormone is used to increase metabolic rate?
Thyroxine
The inverse square law in relation to light intensity (i) and distance (d) from the light source is shown by :
i∝1/d^2
The pH falls as the fat in milk breaks down.
Explain why
Produces fatty acids
A teacher states that collecting the gas, for example in a gas syringe, would grave a more accurate measurement.
Explain why
It gives the total volume
Describe how and where oxygen is produced in photosynthesis
Light energy splits water in chloroplasts
Explain why the amount of oxygen given off is not a true measurement of the rate of photosynthesis
Some oxygen is used up in respiration
Respiration is also occurring
Why is it important to keep the light intensity the same when doing an experiment?
A light intensity increase would open the stomata, increasing transpiration.
Why is it important to keep the temperature the same?
In a practical of transpiration .
Increase in temperature increases evaporation.
Describe how oestrogen and FSH interact during the menstrual cycle.
FSH stimulates oestrogen production , and oestrogen inhibits FSH production.
Explain why most large multi-cellular organisms need transport systems, such as the blood system, but most single celled organisms do not.
as size increases the rate of diffusion decreases . It would take too long for substances to diffuse in and out of large organisms.
Oxygen enters red blood cells by diffusion.
Describe and explain how red blood cells are adapted for the efficient uptake and transport of oxygen.
- They are flexible to get into small vessels.
- The cells are biconcave disc shape therefore has large surface area:volume
- Haemoglobin to carry oxygen
