2017 Biology Paper 1 Flashcards
1
Q
Why are some moths and bumblebees described as endothermic?
A
- They have scales and hair to reduce heat loss.
- They generate heat from respiration / metabolism
2
Q
What fluid is found in the tracheoles of insects?
A
tracheal fluid
3
Q
Why do insects and other animals need well-developed transport systems?
A
- They have high metabolic demands.
- They need a rapid oxygen supply.
- Diffusion is not sufficient (because distance is too far).
- (Transport system needed) to maintain a steep diffusion gradient.
- Their surface area to volume ratio is low.
- Metabolites needed by cells, and waste products need to be removed from cells.
4
Q
Why does blood and faeces have the highest concentration of C-reactive protein and copeptin? (Molecules produced in the liver)
A
- The liver has a large blood supply.
- C-reactive protein and copeptin are secreted into bile.
5
Q
What indicates that a Trasmission Electron Microscope was used to create a micrograph of cell tissue?
A
- 2D image
- internal details visible
- organelles visible
- high magnification
- high resolution
6
Q
What is a limiting factor?
A
- A factor that limits the rate…
- …when at a sub-optimal level.
7
Q
What is an organ?
A
- An organ is a collection of tissues…
- …adapted to a function.
8
Q
Why are podocytes unable to undergo mitosis?
A
- They are already differentiated.
- They are in the G₀ phase.
- Their shape is too irregular.
- Spindle fibres cannot form.
