June 2017 Practice Paper Flashcards
Why can hCG be detected in urine?
It has a molecular mass of less than 69,000
Describe the process of adhesion
Attraction of water molecules to the impermeable walls of xylem tissue
Mistletoe binds to plant stems and contains not chloroplasts. How can it survive?
It attaches to sieve tube elements
What are the holes in insects that let air in called
Spiracles
Fluid responsible for gaseous exchange in insects?
Tracheal fluid
Reasons for well developed transport systems in animals
- SA:V too low for natural diffusion of all needed substances
- they are metabolically active
- need an even dispersion of substances around the body
- insufficient diffusion
- insufficient oxygen
What to consider when drawing a diagram
- no shading
- large scale
- title
- labels outside diagram
- continuous lines
- labels don’t cross out others
- plain paper
- correct proportions
- state magnification
Formula for sphere volume
V=4/3πr3
Difference between scanning and transmission microscope?
Scanning gives a 3D image
Transmission gives a 2D image
How can you identify a TEM image?
- 2D image
- internal details visible
- organelles/ultrastructure visible
- high mag, high res
Limiting factor definition
Factor that will determine the RATE when at a sub optimal LEVEL
Why does over watering kill plants in terms of aerobic and anaerobic respiration?
- not enough oxygen
- anaerobic takes place
- less ATP created as a result
- less active transport as a result
- less mineral ions into roots as a result
- less movement of water by osmosis into the plant
Why can water molecules form hydrogen bonds with some ions?
- water is polar
- ions are charged
- hydrogen bonds formed with the delta positive hydrogen or delta negative oxygen in water
Nucleic acid monomer=
Nucleotide
What forms the backbone of a nucleotide?
Phosphate group between pentose molecules
