Mendelian principles. Flashcards
What does the principles of the Mendelian inheritance describe?
how some traits involved with appearance result from the inheritance of a single gene copy from the female and an allele from the male.
What are the two different types that single gene disorders can be?
recessive.
dominant.
What is the definition of a recessive allele?
when both copies of the allele need to be present.
What is the definition of a dominant allele?
when only one copy of the allele needs to be present.
What is the definition of an allele?
alternative versions of genes.
What is the definition of a trait?
genetically determined characteristics.
What is the definition of homozygous?
inheriting two identical copies of the same allele for a gene, one from a female and one from a male.
needs to be either two dominant or two recessive.
What is the definition of heterozygous?
inheriting two different alleles for a gene.
needs to be one recessive and one dominant.
What is the definition of a genotype?
genetic makeup.
What is the definition of a phenotype?
appearance that has been resulted from the genetic makeup.
What are the four main genetical disorders that we need to know about?
phenylketonuria (PKU).
cystic fibrosis.
Huntington’s disease.
sickle cell disease.
What type of allele causes PKU?
recessive.
What type of allele causes cystic fibrosis?
recessive.
What type of allele causes Huntington’s disease?
dominant.
What type of allele causes sickle cell disease?
partially dominant.
