Chapter 18: Inheritence Flashcards
What is an allele?
Alternate forms of the same gene found on corresponding gene locus of homologous chromosomes
What is the difference between pheontype and genotype?
Pheontype is the expressed trait (physical trait) of an organism, genotype is the genetic make-up of an organism (combination of genes)
What does it mean when a trait is homozygous?
The 2 allels that control that trait are identical (PP or pp)
What does it mean when a trait is heterozygous?
The 2 alleles that control that trait are different (Pp)
What is the difference between complete and incomplete domincance?
Complete: The combination of the dominant and recessive allele expresses the trait of the dominant allele
Incomplete: The combination of the dominant and recessive allele expresses the traits of both alleles leaning more to the dominant phenotype
What is codominance?
Both alleles having an equal effect on the phenotype of the offspring
What are variations?
Differences in traits between individuals of the same species
What is the difference between discontinued and continued variation?
Discontinued variation is brought about by one or a few genes (blood type), while continued variation is brought about by the additive effect of many genes (skin tone)
What is a sex-linked gene?
A gene that is located on sex chromosomes
Which sex chromosome has more genes found on it?
X-chromosome
What are some X-linked disorders?
Red-green colourblindness, Muscular Distrophy