INHERITANCE
AND EVOLUTION
Biology GCSE Revision Booklet
, Inheritance – Key Words
→ Genome – The entire genetic material of an organism
→ Gamete – The sex cells (sperm and egg cells) which contain 1 set of genetic
information
→ Gene – A section of DNA that codes for a particular sequence of amino acids to make
a specific protein. Genes carry information for particular characteristics, such as ear
shape or eye colour.
→ Chromosome – Found in the nucleus, made from long DNA molecules and passed
from parent to offspring
→ Allele – A different form or variant of a gene
→ DNA – A polymer made up of 2 strands of nucleotides that are twisted to form a
double helix structure
→ Dominant – Controls the characteristic, even if only present on 1 chromosome
→ Recessive – Only controls a characteristic is present on both chromosomes
→ Homozygous – 2 identical alleles for a characteristic
→ Heterozygous – Different alleles for a characteristic
→ Genotype – The alleles in an individual for a particular characteristic
→ Phenotype – The physical appearance of an individual for a particular characteristic
→ Meiosis – A type of cell division that involves 2 nuclear divisions, producing 4 non-
identical daughter cells. Each daughter cell contains 1 set of chromosomes
→ Mitosis – A type of cell division that involves 1 nuclear division, producing 2 identical
daughter cells, each containing 2 full sets of chromosomes
→ Sexual Reproduction – produces new organism from the combined DNA of 2
parents. Involves production of gametes which join at fertilisation
→ Asexual Reproduction – Only 1 parent with no fusion of gametes. Only mitosis
involved, therefore no mixing of genetic information. Offspring are genetically
identical (cloning)
AND EVOLUTION
Biology GCSE Revision Booklet
, Inheritance – Key Words
→ Genome – The entire genetic material of an organism
→ Gamete – The sex cells (sperm and egg cells) which contain 1 set of genetic
information
→ Gene – A section of DNA that codes for a particular sequence of amino acids to make
a specific protein. Genes carry information for particular characteristics, such as ear
shape or eye colour.
→ Chromosome – Found in the nucleus, made from long DNA molecules and passed
from parent to offspring
→ Allele – A different form or variant of a gene
→ DNA – A polymer made up of 2 strands of nucleotides that are twisted to form a
double helix structure
→ Dominant – Controls the characteristic, even if only present on 1 chromosome
→ Recessive – Only controls a characteristic is present on both chromosomes
→ Homozygous – 2 identical alleles for a characteristic
→ Heterozygous – Different alleles for a characteristic
→ Genotype – The alleles in an individual for a particular characteristic
→ Phenotype – The physical appearance of an individual for a particular characteristic
→ Meiosis – A type of cell division that involves 2 nuclear divisions, producing 4 non-
identical daughter cells. Each daughter cell contains 1 set of chromosomes
→ Mitosis – A type of cell division that involves 1 nuclear division, producing 2 identical
daughter cells, each containing 2 full sets of chromosomes
→ Sexual Reproduction – produces new organism from the combined DNA of 2
parents. Involves production of gametes which join at fertilisation
→ Asexual Reproduction – Only 1 parent with no fusion of gametes. Only mitosis
involved, therefore no mixing of genetic information. Offspring are genetically
identical (cloning)
