definitions Flashcards
Asexual reproduction
Production of offspring without joining of gametes
sexual reproduction
Production of offspring by joining gametes
gamete
sex cells (sperm and ova)
gonad
organs that produce gametes (testes & ovaries)
menstruation
Shedding of uterine lining (endometrium) at the start of the menstrual cycle
ovulation
release of an ovum from an ovary, normally occurs in the middle of the menstrual cycle
fertilisation
Union of ovum and sperm (to form a zygote)
implantation
Sinking into the endometrium of an embryo
zygote
Fertilised ovum
embryo
Early stage of development of a foetus
karyotype
An image depicting the full complement of an individual’s chromosomes
gene
regions of DNA that code for the production of specific traits.
chromsomes
long thin strands of DNA that are located in the nucleus of cells. They contain genes.
homologous
Matching (eg homologous chromosomes are matching chromosomes)
autosome
chromosomes (other than sex chromosomes) that do not code for gender (eg 1 to 22 in humans)
sex chromosome
chromosomes that do code for gender (23rd pair in humans)
maternal chromosome
from mother (in ovum)
paternal chromosome
from father (in sperm)
DNA
Deoxyribonucleic Acid – a double helix shaped chemical that makes up chromosomes
nucleotide
building block of DNA