Aqa A Level Biology Paper 1/3 |302 Questions| With Correct Answers.

Genome {Ans: The complete set of genes in a cell}Transfer RNA {Ans: tRNA is a single polynucleotide strand that folds back on its self forming hydrogen bonds between complementary base pairs within the molecule. It's carries a specific amino acid and has a specific sequence of three bases called an anticodon which is complementary to the codon on mRNA.}3 functions of a cell membrane {Ans: 1) control transport of substances in an out of the cell as the membrane is partially permeable 2) acts as a receptor site 3) separates cell and organelles from each other}Why are the walls of the left ventricle thicker than the walls of the right ventricle? {Ans: The left ventricle needs to contract with more force and generate a higher blood pressure so that blood can be pumped all around the body rather than just to the lungs like the right ventricle. Ventricles have a thicker wall than atria as blood has to travel a further distance.}What do chromosomes look like when DNA replicates ? {Ans: Two sister chromatids held together by a centromere}How does substrate concentration affect enzyme activity and what does the graph look like ? {Ans: