Topic 3 Flashcards
what is the structure of bacterial Dna
circular with no nuclear membrane
Describe how DNa is organised in a bacterial cell
large cicular dna
small plasmids
located in cytoplasm not in nucleus
Describe what happens to lysosomes once there contents have been released
lysosome fuse with cell membranes contents released from the cell via exocytosis
3 differences between eukaroytic and prokaryotic organisms
eukaroytic organisms have membrane bound organelles
eukaroytic organisms have a nucleus prokaryotic dont
size of ribosomes larger in prokaryotic
eukarotic organisms dont have plasmids.
what happens to lactate when it is absorbed from the blood
lactate is converted to pyruvate which is used in respiration
3 features that could be used to identify prokaryotic cells in a blood sample
no nucleus
plasmids
smaller ribosomes
circular dna
presence of cell wall
explain why the nucleus cannot be observed at the end of the prophase in a eukaryotic cell
end of prophase nucleus is pulled apart by spindle fibres meaning it isn’t in tact to observe
two functions of golgi apparatus
modifies proteins
forms vesicles
3 phases of developing a new drug
find safe dosage
see if drug is effective
gather data too test for rare side effects
where is the bacteria capsule located
outside the cell
what does the term polygenic mean
a characteristic showing continuous variation caused by multiple genes at different loci
explain how epigenetic changes affect the development of tissues in the embryo
dna is wrapped around histones
modification of the histones prevents chromosome unwinding
therefore gene expression is faulty
deduce why people with a mutation of a gene for a particular protein makes them resistant to HIV
the receptor that binds to HIV is unable to bind with the receptor so HIv cannot enter the cell
explain why stem cells can help prevent HIV causing aids
stem cell can differentiate into any cell
they can differentiate into T helper cells which are resistant to HIV
T helper cells can also be destroyed by HIV which prevents the patient from producing a immune response
due to these t helper cells being destroyed HIV isn’t present in the blood
one difference between a tissue and a organ
tissue is made up of one type of cell and a organ is made up of different tissues