Exam 1 Flashcards
how do you find the possible number of gametes?
2^n, where n is the haploid number of chromosomes
how many primary spermatocytes are formed? how many secondary spermatocytes are formed?
4; 2
what are the two typical testcross ratios?
3:1 and 9:3:3:1
autosomal
not X linked
in chi-square analysis, what happens if p is less than .05?
we reject the null hypothesis; If a value is less than .05, then 5% of the time the results will be achieved by chance alone
in chi-square analysis, what happens if p is greater than .05?
we fail to reject the null hypothesis
incomplete dominance
- expressing a heterozygous phenotype that is distinct from either homozygous parent
- RR red flower + rr white flower = Rr pink flower
codominance
- a condition in which phenotypic effects of a gene’s alleles are fully and simultaneously expressed in the heterozygote
- RR red flower + rr white flower = Rr red flower
multiple alleles
-in a population of organisms, the presence of three or more alleles of the same gene
does not exist in individuals, only populations
-Different types of the same gene, can be seen in ABO blood groups
epistasis
the nonreciprocal interaction between nonallelic genes such that one gene influences or interferes with the expression of another gene, leading to a specific phenotype
position effect
- a change in expression of a gene associated with a change in the gene’s location within the genome
- If a gene is translocated, that region of the chromosome may be modified. So, if a gene is expressed for red eye color and is moved, that may result in a white eye color instead
autosomal dominant
one copy of a dominant allele causes the trait to be prevalent
autosomal recessive
inherit two copies of a recessive allele for the trait to be prevalent
X-linked dominant
a gene responsible for a genetic disorder is located on the X chromosome, and only one copy of the allele is sufficient to cause the disorder when inherited from a parent who has the disorder.
X-linked recessive
genetic conditions associated with mutations in genes on the X chromosome. A male carrying such a mutation will be affected, because he carries only one X chromosome. A female carrying a mutation in one gene, with a normal gene on the other X chromosome, is generally unaffected.
inversion loop
the chromosomal configuration resulting from the synapsis of homologous chromosomes, one of which carries an inversion
paracentric
a chromosomal inversion that does not include the region containing the centromere
what results from a paracentric inversion?
in a single crossover of a heterozygote, two altered chromosomes, one acentric and the other is dicentric
pericentric
a chromosomal inversion that involves both arms of the chromosome and thus the centromere
what results from a pericentric inversion?
in a single crossover of a heterozygote, two altered chromosomes, both are duplicated and deficient
acentric
lacking centromeres
dicentric
two centromeres
cytoplasmic inheritance
controlled by genes present in the cell cytoplasm rather than by genes on the chromosomes in the cell nucleus
genomic imprinting
inheritance of traits controlled by a single gene with two alleles, one of which may be completely dominant to the other
