AQA AS-Level Biology Unit 2 [Unofficial Markscheme]Watch
EDIT: I WILL CORRECT EVERYTHING WHEN I GET A COPY OF THE QUESTIONS
1.a Coronary artery transports blood to heart muscle cells providing them with glucose and o2 for respiration allowing them to contract
b.Blood vessels A H E
c. Aorta has a bigger elastic layer, highest pressure exerted out of all vessels, elastic layer stretches and recoils at systole/diastole
2.a.Female lizards wider range, higher mean length
b.Lower plants diversity results in fewer habitats/niches/food sources, reduces insects and therefore lizard species diversity(Dont remember the order or numbers of questions sorry so ill just list what i remember)-
cellulose and starch differences: 1. Starch made from alpha glucose, cellulose beta2. No microfibrils in starch-similarities: 1. Both polysaccharides made from identical repeating monomers2. Both contaon glycosidic bonds
Adaptations of cells: sieve cell- large vacoule allows fast rate of mass flow, little resistance (probs wrong)Helper/companion cells: many mitochondria, produce lots of ATP used for active transport of sugars
Crickets questions:Courtship behaviour causes: -stimulates release of gametes-allows for identification of same species partners-identifies fertile/sexually mature partners
Place the male with both wings with the same females, record percentage showing courtship after song, compare values to recorded song
Dna q: humans and grasshoppers may have similar & of bases but different sequences resulting in different codons coding for different amino acids hence different proteinsb.
Viral dna single strand, as no base pairing due to different %s of c+g and a+t
Differences bacterial and human dna: bacterial circular, as plasmidBacterial not associated with proteins
Genetic bottleneck question: small population, low genetic diversity/small gene pool, inbreeding increases frequency of faulty allele as it ispassed onfo offspring
Ratio 32:1 (to all of you arguing yes, it was more frequent in the small population but the population of america was much, muchh greater so overall more people are colour blind in USA)
Classification:- no overlaps between groups therefore it is a hierarchy
-mutation is a change in specific dna base sequence, affecting at least one codon
-this changes the specific amino acid sequence-resulting in a different primary polypeptide shape
-therefore different secondary shape as hydrogen bonds form between different amino acids and different places in the chain-different tertiary shape of enzyme-alters shape of active site, no longer complementary to substrate
-no e-s complexes formed
I thought it would be AHF because F was on the side of the aorta so would be the renal artery - E was on the same side as A (It went AB, CD, EF) so would be renal vein?
- EDIT: Apparently I dun goofed, and the ones I put were AHE as other people are saying. Apparently when I was remembering it I thought it was the other way around.
It was the bottom left one
For the 4 marker on mitiosis, you AREN'T REALLY SUPPOSED TO DESCRIBE THE STAGES fully. What you do do is explain how the ddaughter cells are identical = stuff like: chromosome no. stays the same throughout, no independent segregation nor crossing over so no genetic variation. Then you talk a little about the stages (i.e. interposer = DNA rep and cytonkenisis = two new cells formed).
I just spoke about interphase