AQA BIOL2 Biology Unit 2 Exam - 26th May 2011

s1? what is this? Are you talking about biol2?

Statistics 1.

Lucky you getting to sleep in Most people here have got S1 in the morning I think?

A species is a group of organisms that can reproduce together to produce fertile offspring. The difficulty in establishing this could result from species being rare and hard to make mate in isolation, and the ethical implications of interfering with the organism to get the DNA sample or what-not.

Taxonomy is the classification of organisms into a hierarchy. The hierarchy simply being large groups containing smaller groups with no overlap, and allowing organisms to be classified by their common ancestor and evolutionary relationship(phylogenetic classification), or grouping into groups of similar phenotypes/characteristics and alleles.

The ethical implications of antibiotic resistance mean that bacteria have gained a selection advantage as a result of their mutated resistance gene, and due to this modern antibiotics may not work on them, and without use of multiple antibiotics can result in strains of bacteria resistant to multiple antiobiotics. This can result in more suffering for patients and animals who are infected with these strains as they cannot be treated as effectively as well as leading them to die in this time.

-Might be extinct, nocturnal.
-Because some countries have different names for the same organisms so a scientific name helps to identify what they are talking about.
-Not sure what you mean? Like testing antibiotics on animals?

I really hate that they are both on the same day! I'm so gonna flop one of them . Stupid Stats.

I have C2 the same daay! And chem 2 the day after

Yeah, the DNA replicates during interphase, that's why the chromosomes appear as the 'X' shape. Originally, it's just one 'strand', one chromatid. After replication, you have two sister chromatids, which are then separated during mitosis.

I have C2 the same daay! And chem 2 the day after

s1? what is this? Are you talking about biol2?

I really hate that they are both on the same day! I'm so gonna flop one of them . Stupid Stats.

Got chemistry and economics the day after... D:

Prophase is when the chromosomes coil up/condense and telophase is when they uncoil, so there will still be the same number of chromosomes. But the mass of DNA in telophase will be half that in prophase because at prophase the amount of DNA will have doubled (DNA replication) and after telophase the cell will have already have divided and the mass of DNA would have been halved. 26 chromosomes and 30 mass of DNA will be the "normal" amount.

Because telophase and prophase are apart of mitosis they are involved in diploid cells and because a sperm cell is a haploid cell it will have half the number of chromosomes and therefore half the mass of DNA.

Hope that helps.

omgomgomgomg i'm suddenly very panicked about this exam. has anyone found or made any good summary notes?

omgomgomgomg i'm suddenly very panicked about this exam. has anyone found or made any good summary notes?

I just want to make sure I have the stages of the cell cycle/mitosis right.

Am I missing anything?