Inheritance Flashcards
What is a phenotype?
the physical appearance of an organism due to expression of its genotype- and its interaction with the environment
What is a gene?
a length of DNA coding for a particular protein
What is a genotype?
the genetic makeup of all the alleles in an organism
What is an allele?
an alternative form of the same gene, may be several different ones
What does recessive mean?
an allele that is only expressed if there are no dominant alleles present-mutation of a gene that cannot code for an enzyme/protein
What does co-dominant mean?
alleles that are equally dominant and both will be expressed if they are present
What does homozygous mean?
when both alleles present are the same
What does dominant mean?
if the allele is present it will be expressed- normal gene able to code for an enzyme/protein
What is the expected ratio for heterozygous parents in a monohybrid cross?
3:1
How do you find out the genotype of an organism showing dominant characteristics? (monohybrid cross)
cross it with a homozygous recessive-
if ALL offspring have dominant characteristic then the parent must be homozygous dominant
if SOME but not all offspring have dominant characteristic then the parent must be heterozygous
What is codominance?
alleles that have equal dominance and are both expressed in the phenotype. the traits appear together in the phenotype
What is the difference between co-dominance and incomplete dominance?
co-dominance- both alleles expressed equally
incomplete dominance- phenotype is a mix of both alleles (eg. red and white having the phenotype of pink)
What are multiple alleles?
when a gene has more than two potential alleles
Give an example of a gene with multiple alleles
blood group
