biology paper 1 Flashcards
how does the order of amino acids in a protein is determined by gene sequence
a single strand of messenger rna is transcribed from the gene in the nucleus
messenger rna molecules binds to the ribosome
the triplet code from the MRNA is matched by a complementry + rna anticodon at the ribosome
tRNa transfers amino acids to the polypeptide chair in a specific order
describe how monoclonal antibodies are deloped to detect STI in a urine test
isolate an antigen from the pathogen which is the sti
inject the antigen into a rodewnt
collect lymphocytes producing an antibodies to the STI antigen
fuse the b- lymphocytes with a melanoma cell. production of a hybridoma which produces a monoclonal antibody against the antigen of the STI
attach the monoclonal antibody to coloured bead and incorporate into a test strip
how to produce genetically modified bacteria that bmakes penicillin
use of restriction enzymes to remove the gene and cut the plasmid
use of ligase to join the DNA molecules togeth
cut the gene from the genome of the fungus and extract a plasmid from the bacteria insert the recombinant plasmid back into the bacteria
why does phenolphthalein turn colourless when lipase breaks down lipids
fatty acids are formed when the lipds are broken down by lipase
and fatty acids are acidic so the ph decreases
effect of penicillin on bacteria and human cells (3)
prevents the bacteria from dividing as they cannot make a new cell wall
human cells do not have a cell wall so they are not affected by penicillin
how to grow drought resistant plants
genetic variation = some plants will be tolerant to droughts
cross - pollinate these plants
select offspring and repeat over several generations
evidence to date how old species is
fossil structure
older fossils are deeper down in the rocks
how embryonic stem cells are used to treat disease
embryonic stem cells are stimulated to produce cells of the retina
which can be transplanted into the patients eye to replace the damaged cells
benefits of asexual reproduction (3)
rapid reproduction technique allowing the production of more plants
as there is no requirement of cross pollination
higher crop yield
-> increased profit
why is reproduction via seed/pollination good
introduces variation into the population
which allows for natural selection
Describe the advantages of producing plants by tissue culture .
- many plants produced (1)
- quicker than sexual
reproduction (1)
genetically identical/ clones
produced (1)
with the desired
characteristics (1) - plants from
{endangered/rare} plants (1)
Describe the possible benefits of this research on stem cells
have the potential to produce any
cell type (1)
* no need to use embryonic stem cells
less chance of patient rejecting their
own cells (1)
used to treat conditions which are
currently incurable / used for cell
transplants /used to replace faulty
cells (1)
the role of ethanol in DNA extraction
to percipitate the DNA
explain how bacteria become resistant to antibiotics
patients to not finish course of antibiotics
natural selection/evolution occurs
some bacteria have a mutation/genetic mutation
resistant bacteria survive//resistant bacteria reproduce
give reasons why the three domain methods of classification are used
improved genetic analysis
DNA/RNA [sequencing/screening]
domain theory is based on genetics
differences between coding and non-coding DNA