Inheritance- BP Flashcards
What is inheritance?
offspring inheriting a combination of alleles (2 types – paternal/maternal) for each gene which will help determine characteristics
What is a gene?
a section of DNA that codes for a protein
What is an allele?
a type/form of a gene
What is a dominant allele?
an allele that is always expressed if present
What is a recessive allele?
an allele that is only expressed if 2 are present
What is genotype?
combination of alleles for a particular gene
What is phenotype?
expressed/observed characteristic (if discontinuous – only determined by genotype, if continuous – determined by genotype and environment)
What is homozygous?
having 2 of the same alleles
What is heterozygous?
having 2 different alleles
What is Monohybrid Inheritance?
inheritance dealing with One Characteristic
Examples of Monohybrid Inheritance?
Dominant/Recessive
Codominant
Multiple Allele
Sex Linkage
What is the Expected Ratio for Monohybrid Dominant/Recessive?
3 Dominant to 1 Recessive
Why are Observed Ratios different from Expected Ratios?
random fertilisation of gametes
small sample size
mutation
selection
How can 2 parents with a dominant characteristic give birth to a child with a recessive characteristic?
if both parents are Heterozygotes (carriers for recessive allele) they have a 25% chance of giving birth to a child who is Homozygous Recessive (has the recessive characteristic)
What is co-dominance?
when 2 different dominant alleles are inherited, both will be expressed in the phenotype
