Inherited change Flashcards
Genotype
Genetic constitution of an organism
Phenotype
the observable characteristics of an organism
gene
a length of DNA that is a sequence of nucleotide bases that code for a particular polypeptide
allele
One of the different forms of a gene
how many alleles per gene do diploid organisms have
2
dominant allele
characteristics will be expressed in the phenotype whether one or two alleles are present
recessive allele
characteristics only appear in the phenotype if the dominant allele ISNT present, meaning two recessive alleles are present
homozygous
both alleles for the characteristic are present in the organism
heterozygous
if the two alleles are different
monohybrid inheritance
the inheritance of a single gene
law of segregation
in diploid organisms, characteristics are determined by alleles that occur in pairs. only one of each pair of alleles can be present in a single gamete
dihybrid inheritance
how to characters determined by two different genes located on different chromosomes are inherited
codominance
both alleles are expressed in the phenotype
multiple alleles
where there are more than two alleles of which only two may be present at the loci of an individual’s homologous chromosomes
sex-linkage
where an allele is located on one of the sex chromosomes, meaning its expression depends on the sex of the individual
why are males more likely to express a recessive sex-linked allele
Most sex linked alleles are located on the x chromosome. Therefore males only get one copy of the allele, so will express this characteristic even if it’s recessive
autosomal linkage
two or more genes are carried on the same autosome
epistasis
the allele of one gene affects or masks the expression of another in the phenotype
what is the chi-squared test
used to test the null hypothesis
null hypothesis
used to examine the results of scientific investigations and is based on the assumption that there will be no statistically significant difference between sets of observations, any difference is due to chance alone
What is the criteria for the chi-squared test
- data placed in discrete categories
-large sample size
-only raw count data allowed
-no data values equal 0
