2012 Flashcards
Define pollination
Transfer of pollen from anther to stigma
Where does the fusing of sperm and ova take place?
Fallopian tube
What are acrosomes?
They contain enzymes
What are similarities between plant fertilisation and human fertilisation?
Enzymes used Formation of tube Nucleus travels along channel into ovule Both are chemotrophic Membrane burst to release make gametes
What is meant by gene therapy?
Inserting normal DNA sequence
What happens in somatic cell therapy?
It targets cells in affected tissues and is not inherited
What is germ line therapy?
Introduces genes into egg and is inherited
What technique could be used to introduce CFTR genes into someone with cystic fibrosis?
Modified genes are inserted into liposomes which fuse with cell membrane. The modified gene passes through membranes into cell which is applied by an inhaler
Why is replication of DNA is described as semi-conservative?
Each new DNA molecule consists of one original strand and one new strand
In polymerase chain reaction why is temp reduced to 55
Triggers primers so DNA Helices can join together
I’m polymerase chain reaction why is temp increase to 70
DNA polymerase catalysed synthesis of complementary strand
Why is not safe to use PCR to clone the CFTR gene for use in treating cystic fibrosis?
Incorrect base sequence Incorrect mRNA Different tRNA Sequence of amino acid altered Thick mucus still produced
Name enzyme involved in transcription stage of protein synthesis
RNA polymerase
How tetracycline stops protein synthesis?
Translation can’t occur
Tetracycline binds with codon
tRNA triplet can’t pair with codon
Amino acid not added to polypeptide chain
What is meant by succession?
Change in structure in a community over time
Change in species present over time ether due to change in environmental or abiotic factors
