Inheritance (10 BIOCHEM)

Inheritance

The transmission of genetic information from generation to generation.

Chromosome

A strand of DNA which contains multiple genes.

gene

A length of DNA that codes for a protein

allele

A version of a gene

DNA

(deoxyribonucleic acid) a complex molecule containing the genetic information that makes up the chromosomes.

sex chromosomes

X and Y chromosomes.

haploid nucleus

a nucleus containing a single set of unpaired chromosomes (e.g. sperm and egg)

diploid nucleus

a nucleus containing two sets of chromosomes (e.g. in body cells)

mitosis

A nuclear division giving rise to genetically identical cells.

daughter cells

new cells produced by cell division

meiosis

Nuclear division giving rise to cells that are genetically different. Reduction division in which the chromosome number is halved.

genotype

the genetic make-up of an organism in terms of the alleles present.

phenotype

the observable features of an organism due to genotype and environment.

homozygous

Having two identical alleles of a particular gene

heterozygous

An organism that has two different alleles for a particular gene

dominant phenotype

Only one copy of the allele is required for the trait to be expressed in the phenotype

recessive phenotype

Two copies of this allele are required for the trait to be expressed in the phenotype

pedigree diagram

a diagram that shows the occurrence of phenotypes of a particular gene or trait

trait

A characteristic that an organism can pass on to its offspring through its genes.

Fertilisation

Fusing of a male sex cell with a female sex cell.