Chapter 4 Flashcards
Define incomplete dominance and give an example
An intermediate phenotype is expressed (ex: red and white flower make pink flower)
Define codominance
Both alleles and phenotypes are expressed
Chromosomes X and Y are called ________ chromosomes, all other chromosomes are called what?
sex chromsomes; autosomes
Males are more likely to inherit what kind of genetic condition?
X-chromosome linked
Any cell with 23 pairs of chromosomes is ___________; any cell with 23 unpaired chromosomes is _________.
diploid; haploid
Individuals with two identical alleles for a trait are ____________; individuals with two different alleles for a trait are ____________.
homozygous; heterozygous
An allele/ trait that is masked by a dominant trait is said to be what?
Recessive
The two alleles for a trait make up what?
A genotype
Define polygenic inheritance
When genes at 2 or more loci contribute to 1 phenotype
Define pleiotropy
One gene has multiple effects
Define epigenetics
The idea that gene expression can change and be passed down through generations without altering gene structure
Define karyotype
A chart of all 46 chromosomes
Each pair of chromosomes is said to be what?
Homologous
If a dominant allele is silenced and has no effect on some people who carry it, it is said to show ____________ ____________ in that population
incomplete penetrance
What things affect gene expression
1) Environmental factors
2) Nutrition (some genes need enzymes to be expressed)
True or false: only 5-10% of cancers are hereditary, but all are genetic
True; cancer is typically due to mutation, all have genetic abnormality
Mutations in tumor suppressing (TS) genes can lead to what?
Cancer
How do tumor suppressing genes inhibit cancer?
By inhibiting oncogenes
