Exam 1 Flashcards
G 1
cell grows and prepares for DNA replication by synthesizing proteins and organelles
S
DNA synthesis/ replication -> creates 2 identical copies of the genome
G2
2nd growth phase were nuclear envelope envelopes and 2 centromeres are formed
homologous chromosomes
pair of chromosomes with same genes but different alleles (same info different version)
sister chromatids
identical copies of single chromosome created during DNA replication
in 2n=6 what does 6 mean
total chromosomes per cell
chromosomes per cell in mitosis prophase
same as beginning
chromosomes per cell in mitosis metaphase
same as beginning
chromosomes per cell in mitosis anaphase
double beginning
chromosomes per cell in mitosis telophase
double beginning
chromosomes per cell in mitosis product
same as beginning
chromatids per chromosome in mitosis prophase
2
chromatids per chromosome in mitosis metaphase
2
chromatids per chromosome in mitosis anaphase
1
chromatids per chromosome in mitosis telophase
1
chromatids per chromosome in mitosis products
1
chromosomes per cell in meiosis prophase 1
same as beginning
chromosomes per cell in meiosis metaphase 1
same as beginning
chromosomes per cell in meiosis anaphase 1
same as beginning
chromosomes per cell in meiosis telophase 1
same as beginning
chromosomes per cell in meiosis prophase 2
half beginning
chromosomes per cell in meiosis metaphase 2
half beginning
chromosomes per cell in meiosis anaphase 2
same as beginning
chromosomes per cell in meiosis telophase 2
same as beginning
chromosomes per cell in meiosis products
half beginning
chromatids per chromosome in meiosis prophase 1
2
chromatids per chromosome in meiosis metaphase 1
2
chromatids per chromosome in meiosis anaphase 1
2
chromatids per chromosome in meiosis telophase 1
2
chromatids per chromosome in meiosis prophase 2
2
chromatids per chromosome in meiosis metaphase 2
2
chromatids per chromosome in meiosis anaphase 2
1
chromatids per chromosome in meiosis telophase 2
1
chromatids per chromosome in meiosis products
1
allele
variation of a gene
in 2n=6 was does 2 represent
number of sets of chromosomes (2 of each type)
meiosis division 1 is the separation of —
homologs
meiosis division 2 is the separation of —
sister chromatids
crossing over happens in —
meiosis prophase 1
separation of x and y happens in —
meiosis anaphase 1
nondisjunction
when chromosomes don’t separate properly
random segregation
2 alleles segregate randomly into the gametes so that half of the gametes contain one allele and half contain the other allele
independent assortment
segregation of alleles at one locus is independent of segregation of alleles at another locus
meiosis produces
- haploid gametes with half the number of chromosomes as parent
- 4 unique daughter cells
mitosis produces
2 identical diploid daughter cells with same number of chromosomes as parent
to find number of gamete types
multiply how many different alleles they are (Aa=2 while AA=1)
data needs to be smaller in chi square to
fail to reject the null hypothesis
SRY gene determines
whether or not testes form
pseudoautosomal region
regions of homology between X and Y can allow for some crossing over
Lyon hypothesis
inactivation of X chromosome occurs randomly
Barr bodies
inactivated X’s used so females don’t produce double the X-linked gene
affected child with unaffected parents means trait cannot be
dominant
incomplete dominance
- only 1 gene produced
- 1:2:1
codominance
- 1:2:1
- heterozygote expresses both alleles as distinct gene products
lethal alleles
if has that genotype will die (usually homozygous big letter) (dwarfism)
recessive lethal
2 copies of the allele are required to result in death
dominant lethal
death occurs if an individual has only one copy of the allele (huntington’s)
incomplete penetrance
the percent of individuals of a given genotype that show some degree of expression of that gene (quantitative)
expressivity
the range of expression of a genotype (qualitative)
genomic imprinting
expression of a gene depends on whether it is inherited from the maternal or paternal genome
pleiotropic effects
one gene has an effect on several seemingly unrelated aspects of an individual’s phenotype
phenocopy
an environmental agent mimics a genetic condition
sex limited
autosomal characteristics that is expressed in only one sex or the other
sex influenced
autosomal trait that can be expressed in either sex but is more frequent in one sex than in the other
maternal effet
the phenotype of the offspring is determined by the mother’s genotype and not its own
cytoplasmic inheritance
if mother has it all offspring has it
epigenetics
heritable changes in gene expression without changes in DNA sequence (ex is genomic imprinting)
polydactyly
80% penetrance and variable
