bio chp 12 Flashcards
whats the diploid number for fruit flys
8
whats the haploid # for fruit flys
4
how many homologous pairs do humans have
23
what are the first 22 chromosomes referred to as? what do they do?
autosomes
they take care of all the features of the body
what is the 23 chromosome of a human called?
what does it do?
sex chromosomes
determines if baby is male or female
what is the xy for male and femlas
males are xy
females are xx
what holds the sister chromatids together on a chromosome (the middle)
centromeres
why do we need meisosis
allows sexual reproduction of diploid organisms, it enables genetic diversity, and it aids the repair of genetic defects.
what does meiosis do to chromosome number in reproduction1
splits chromosome number in half
in meiosis 1 what lines up
the homologous pairs
what happens in prophase 1
Crossing over. homologoes pairs sometimes overlap and swap sections of dna making unique combo of alleles
what lines up in metaphase 1
homologous pairs
what happens in anaphase 2
pairs separate to opposite poles not chromosomes
As pairs sepearate in anaphase 2 what happens to the alleles
they segragate
after anaphase 2 is telophase partial or complete
how many cells are formed
complete and has 4 cells
is telophase complete or is it just partial
partial because after it goes right into prophase 2
what gets pulled apart during anaphase 2
the sister chromatids the chromosome itself and they go to opposite poles
what is spermatogenesis
the process of sperm cell development
what is meiosis trying to do
where does it occur
get the diploid number and turn it into haploid
just in the gametes
what splits the cells in meiosis
cytokinesis splits the cells
what lines up in metaphase 2
what gets pulled apart
chromosome
chromatids
what is all the genes for an individdual called
genome
what did mendel notice about segragation
segregation happened independantly. independent segregation
what is thomas morgan known for
conducting statistical studies of the way genetic traits are passed on in fruit flies
how many groups did thomas morgan come up with that were dependant on each other
4
what did thomas morgan notice about the 4 groups location
they were located on the same chromosome
what is recombimance
he combination of two DNA strands that are constructed artificially.
which genes are more likely to do the crossing over. the closer ones or the farther ones
the further away ones.
close hardly crossed
what are some mutations
down syndrome
what is chromosomal mutations
changes in structure and number of chromosomes
what are some mutations
deletions,duplications,inversion translocations
waht is nondisjunction
when homologous pairs or ssiter chromosomes dont separate properly
what is the difference in meiosis 1 and 2
in meiosis 1, homologous chromosomes separate, while in meiosis 2, sister chromatids separate
what is a polyploid
when organisms inherit extra sets of chromosomes
what is ploidy level
the number of chromosome sets it hasa
What is crossing over
when does it happen
During propohase 1 of meiosis
homologous chromosomes align and exchange genetic info
what is a karyotype
an image of the chromosome pairs arranged by size, shape, and pattern
what is a pedigree
tools that are used to analyze inheritance
what are chromosomal mutations caused by
cuased by changes to the structure or number of chromosomes
what are chromosomal mutations caused by
changes to the structure or number of chromosomes.
