YEARLY REVISION YEAR 21 Flashcards
name the two types of plant growth regulators, with their roles
Auxins: influence many aspects of growth like elongation growth, which determines the overall length of root and shoot.
Gibberellins: involved in seed germination and controlling stem elongation
how do auxins contribute in elongation growth
Auxins (IAA) are involved in cell elongation. They can be transported up the root or down the shoot by active transport from cell to cell by phloem sap.
1- Auxin binds to receptor protein on cell surface membran
2- This causes ATPase proton pumps to pump H+ from cytoplasm to cell membrane and into cell wall.
3- entrance of H+ causes the cell wall to acidify which leads to a decrease in pH.
4- expansins are proteins present in the cell wall which are activated by a decrease in pH.
5- once activated, expansins loosen linkages between cellulose microfibrils
6- water is absorbed by osmosis
7- pressure potential causes the cell wall to stretch or elongate
how are gibberellins involved in seed germination
gibberelins are plant growth regulators which are involved in seed germination and controlling stem elongation. when a seed is shed from the parent plant, it is in a state of dormancy. when the seed absorbs water, the embryo synthesis gibberellins which diffuses into the aleurone layer where it stimulates cells to synthesize amylase. Amylase hydrolyses starch molecules in the endosperm, converting them into maltose. maltose is then converted into glucose and transported to the embryo from where it can be used for respiration.
genetic cross
- monohybrid cross
- dihybrid cross
Outline the process of PCR
- DENATURATION
2- ANNEALING
3- ELONGATION
1- double stranded dna is heated at 95degrees which breaks the H bonds that bond the two strands together
2- temperatue is decreased to about 65 so that primers can anneal to the ends of the single strands of DNA, by complimentary base pairing, primers redue rebinding of sperated strands
3- temp is incr to 72 which is the optimum temp for TAG polmeraw to create cDNA to produce the new identiacal doube stranded DNA
state the uses of genetic screening and gene therapy
Genetic screening: is the analysis of DNA, to check for the presence/absence of a particular allele in fetus, adults and embryos. the sample of DNA can be obtained by: 1- chorionic villus sampling 2- amniocentesis these are done on embryos and fetuses or 3- taking tissue samples from adults and embryos produced by IVF. BRCA1, BRCA2---- gene therapy: ----
ch5 definitions
notes
bioinformatics
notes s.m.e
state the enzymes used in genetic engineering and their roles
Restriction Endonucleases-
cuts the DNA strand so that the desired gene can be isolated or inserted into a vector
Reverse transcriptase: reverses transcription to form a single strand complementary DNA cDna FROM mRna coding for the desired gene
DNA polymerase: used to convert the single strand cDNA into double strand dna molecule of the desired gene
DNA ligase- used to insert the gene into the vector
cataylsyes the formation of phosphodiester bonds in the DNA sugar phophate backbone
thermoregulation
book
haemophilia
yt video
state RQ alues of lipid protein carbo
carbohydrate 1
lipid 0.7
protein 0.9
define genetic drift
is when there is a gradual change in allele frequencies in a small population due to chance and not natural selection then g.d is occuring. it is most common in smaller populations
selective breeding
types of selection
