Master GCSE Biology

MS1:

- A long, thread-like structure in the nucleus of a cell containing genetic material (DNA) (1)

MS2:

- DNA is a double helix made up of nucleotide bases (1)

- The sequence of these bases determines the genetic code (1)

MS3:

- Genes are located on chromosomes (1)

- During meiosis, chromosomes are copied and separated into gametes (1)

- Fertilisation combines gametes from parents, resulting in offspring with a combination of genes from both parents (1)

MS4:

- A dominant allele is one that expresses its trait even when only one copy is present (1)

- A recessive allele only expresses its trait when two copies are present (1)

MS5:

- Diagram should include:

- Parental phenotypes (1)

- Genotypes of parents and offspring (1)

- Phenotypes of offspring (1)

MS6:

- Mutation changes the genetic code in DNA (1)

- This may alter proteins and alter phenotypes (1)

- If the mutation is advantageous, it may increase the chance of an individual surviving and reproducing (1)

MS7:

- Natural selection favors individuals with advantageous traits (1)

- These individuals have a higher chance of surviving and reproducing (1)

MS8:

- Example: Selective breeding of dogs to produce specific traits (1)

- It allows desirable traits to be passed on to future generations (1)

MS9:

- Ethical concerns may include:

- Potential to alter ecosystems (1)

- Unintended consequences on human health (1)

- Challenges in predicting long-term effects (1)

MS10:

- A genetically identical individual produced from a non-sexual reproductive process (1)