New Specification Qs Flashcards
Why is ATP an immediate energy source and why humans synthesise more than their body mass
ATP Cannot be stored and is therefore an immediate energy source
Release energy in small amounts
Why we need water as a solvent?
Many substances dissolve in water/soluble
Transported in tissue fluid/blood/lymph system
Allows chemical reactions to take place in solution
Allows active transport/facilitated diffusion to take place
How to measure a plant cell length could be estimated
Measure diameter of field with ruler/measure length with eyepiece graticule
Calibrate against something of known length/ calibrate against star micrometer
Suggest an explanation for the rise in miner of deaths from the virus
Mutation of virus
Mutant form not recognised by memory cells (allow antibodies)
How do t lymphocytes work?
T lymphocyte receptors recognise shape of haemagglutin/viral antigen
Clone
Destroy virus
How do B lymphocytes work?
Clone
Produce antibodies
Effect of antibody e.g stimulation of phagocytosis
Precipitation of toxins
What do you look at to diagnose AIDS
Number of t helper cells
AIDS related symptoms
Why HIV test on baby does not necessarily mean baby has HIV
Children receive HIV antibodies from their mothers
So solution will always turn blue/will always test positive (b4 18 months) when baby develops antibody/immune system
Describe translocation in plants?
In source, leaf sugars are actively transported into phloem
By companion cells
Lowers water potential of sieve tube elements and water enters by osmosis
Increase in pressure causes mass movement towards sink
Sugars used/ converted in root for respiration for storage
How to compare between species
Fossil record Evolutionary history Biochemical differences; DNA/proteins/cytochromes Homologous features Karyotype/number and form of chromosomes
