3 Lecture 3 Flashcards
where do homologous chromosomes come from
one from mom and one from dad
how many alleles can a gene have
hundreds, or even more e.g. gene A = earwax A = wet earwax a = dry earwax
which chromosome is the largest
chromosome 1 is the largest chromosome
which chromosome is the smallest
chromosome 21 is the smallest autosome
what chromosome has the fewest genes gene density
the Y chromosome
is gene number always correlated with chromosome size
gene number is not always correlated with chromosome size
where do gametes come from
meiosis separates homologs into cells
now each cell has different alleles for the same gene
what is the process of gametes
meiosis
what are the two rounds of cell division needed
meiosis II
and meiosis II
when does meiosis commence
after interphase
how is meiosis different from mitosis
Meiosis has two rounds of genetic separation and cellular division while mitosis only has one of each. In meiosis homologous chromosomes separate leading to daughter cells that are not genetically identical. In mitosis the daughter cells are identical to the parent as well as to each other
what are the phase of meiosis I
prophase I
Metaphase
anaphase
what is prophase
nuclear envelope starts to break down
microtubules start to assemble. DNA condenses into chromosomes
what is metaphase
homologous chromosomes align at middle of cell
what is anaphase
homologous chromosomes are separated by shortening of microtubules
crossing over in prophase I produces what
different gametes
what happens if crossing over does not occur in prophase I
2 types of gametes are produced
what happens if crossing over does occur in prophase I
4 types of gametes are produced
what else produces different gametes
random alignment in metaphase I
what are the phases in meiosis II
prophase II
Metaphase II
Anaphase II
Telophase II and Cytokinesis
what happens in prophase II
microtubules lengthen
what happens in Metaphase II
chromosomes align at middle of cell
what happens in Anaphase II
sister chromatids are separated by shortening of microtubules
what happens in Telophase II and Cytokinesis
4 haploid daughter cells result. Nuclear envelopes re-form
how does the inheritance of traits work
one gene = one trait = mendalian inheritance
how many alleles are on each chromosome
1
where do alleles come from
come from mutations
are alleles inherited
yes
what is sed to predict the likelihood of getting having dominant/recessive alleles
punnet square
what is the tool used to track family history
pedigree analysis
