April Mock Revision (inheritance + Genetics Only) Flashcards
What is a gene?
A gene is a section of a molecule of DNA that codes for a specific protein.
Where are genes located in a cell?
Genes located on chromosomes inside the nucleus of cells.
How do the bases pair to form a double helix?
Adenine pairs with Thymine, Cytosine pairs with Guanine
How are RNA molecules different to DNA molecules?
RNA molecules are single stranded, they contain uracil instead thymine and the sugar in DNA is deoxyribose whilst the sugar in RNA is ribose.
What is an allele?
An allele is one of many potential versions of a DNA sequence that codes for something specific.
What is the difference between the genotype and the phenotype?
A person’s genotype is the sequence of DNA that codes for a trait, their phenotype is how those genes are expressed in relation to the environment.
What is the difference between haploid and diploid cells?
A haploid cell is a sex cell/gamete that contains one set of Chromosomes, a diploid cell is a normal cell with two sets of chromosomes.
Explain the process of Meiosis. What kind of cell does it produce?
Meiosis is the type of nuclear division that creates genetically different haploid sex cells. The chromosomes double themselves and line up in the middle of the cell. The cell then divides twice - creating 4 different gametes.
What is Mitosis? How does it work?
Mitosis is the kind of nuclear division that gives rise to genetically identical diploid cells. When mitosis occurs, each chromosomes duplicates and the pairs line up in the middle. The cell then divides - taking one of each pair.
What are chromosomes?
Chromosomes are thin strands of DNA subdivided into genes.
