New Specification Qs Flashcards Preview

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Flashcards in New Specification Qs Deck (10):

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
Destroy virus


How do B lymphocytes work?

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