intro to genetics Flashcards
what are population genetics
the study of a gene pool in a populaton overtime
what are molecular genetics
the study of the molecular structure and fincntion of genes
what is the genotype
the allels we have
what is the phenotype
the expression of the genes
what is a gene
an inherited factor that affects the characteristics (phenotype) of an individual
part of a chromosome involved in the transcription of dna into rna
homologous chromsomes consist of
one maternal one paternal
in humans what is the haploid number and diploid number
n=23 2n=46
what is the end product of mitosis
two genetically identical diploid daughter cells
end product of meiosis
4 haploid gametes
where does meiosis take place
in the gonads, eg ovary or testes
interphase includes
G1 S (dna synthesis) and G2
when does mitosis and meiosis begin in the cell cycle
G2
what happens in mitosis prophase
chromosomes condense
mitotic spindle is formed
nuclear envelope breaks down
chromosomes attach to mitotic spindle `
what happens in mitosis metaphase
chromosomes line up at the equator of the cell
sister chromatids are attached to opposite poles of the mitotic spindle
what happens in mitosis anaphase
cohesion between sister chromatids is lost
chromatids segregate to opposite poles driven by shortening microtubules
what happens in mitosis telophase
chromosomes decondense
nuclear envelope reforms
cytokinesis begins
what is n
the haploid chromosome number
the number of bivalents in meiosis is equal to
n the haploid chormosme number
prophase i
chromsomes condense
homologous chromsomes undergo synapsis (pairing)
crossing over occurs
what is crossing over
the exchange of genetic material between non sister chromatids in each bivalent)
metaphase I
each pair of homologous chromosomes lines up at the equator
anaphase i
homologous chromsomes separate to opposite poles
telophase I
each pole has one of the original pair of homologous chromosomes
each chromosome consists of two chromatids
cutokinesis
prophase ii
chromosmes attach to spindle
metaphase ii
individual chromsomes line up at the equator
anaphase ii
sister chromatids separate to opposite poles
telophase ii
each haploid daughter cell carries one chromosome of each cell type
what does independent assortment lead to
different combinations of chromosomes in gametes
what does crossing over lead to
new combinations of alleles on chromsomes
