Genetics Flashcards
ploidy level
the number of chromosome sets that a cell carries Eg haploid 23, diploid 46
homogametic sex
individuals with two of the same sex chromosomes
heterogametic sex
individuals with two different sex chromosomes
somatic cells
all cells in the body of an organism apart form the sex cells (gametes)
germ cells
cells that give rise to gametes
meiosis type of division
reduction division (number of chromosomes becomes halved)
synapsis
when the maternal and paternal homologous pairs of chromosomes pair up
chiasma (chiasmata)
the point on the chromosome where crossing over occurs (the chromosome breaks)
recombinant chromatids/chromosomes
chromatids that have had crossing over occur to them (they have a new combination of alleles)
non-recombinant chromatids/chromosomes
chromatids that have not had crossing over occur to them 9have had no change in their alleles)
formula for number of possible chromosome pairs from independent assortment
2^n where n=the haploid number of the organism
when are chromosomes most visible
at metaphase
genotype
the set of alleles present in the DNA of an individual organism
homozygote
an individual with the homozygous genotype
heterozygote
an individual with the heterozygous genotype
Hemizygous
used to refer to males when talking about X-linked genes. Can be hemizygous dominant/recessive
phenotype
the physical representation of the genotype of an individual
complete dominance
where one allele is dominant over the other so the heterozygous individuals express the dominant trait only