Lecture 13: Intro to Genetics

Heredity

transmission of traits from one generation to the next

Hereditary variation

Dissimilar traits expressed among generations

genetics

scientific study of heredity and hereditary variation

Genes

Code information passed to offspring in hereditary units

How are genes inherited?

1. Asexual reproduction - mitosis

2. Sexual reproduction

lifecycles

generation to generation sequence of stages in the reproductive history of an organism

stomatic cells

any cell in organism excluding sperm + ova

karyotype

method of organising the chromosomes of a cell in relation to number, size and type

homologous chromosomes

chromosomes that make up a pair with similar length, centromere position, and staining

sex chromosomes

determine the sex of an organism

autosomes

all other chromosomes

gametes

reproductive cells with a single chromosomes se

haploid cell

cell with a single chromosome set

number of chromosomes abbreviated n

fertilisation

union of two gametes into an egg

diploid cells

cells with 2 sets of chromosomes including zygotes

abbreviated to 2n

what are the 3 main types of life cycles in multicellular organisms

Animals - gametes only haploid cell

Fungi - zygote is only diploid cell

plants - alternation of diploid + haploid generations

sister chromatids

replicated, identical chromosomes

the mechanisms that contribute to genetic variation

• independent assortment of chromosomes

• crossing over

• random fertilisation