Genetics And Inheritance Flashcards Preview

GCSE Biology*** > Genetics And Inheritance > Flashcards

Flashcards in Genetics And Inheritance Deck (11)
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1
Q

What is an allele ?

A

A form of a gene, represented by either a Capital or a small letter

2
Q

What is a dominant allele ?

A

Allele is always expressed

3
Q

What is a recessive allele ?

A

Two alleles must be present for the characteristic to be expressed

4
Q

What is homozygous ?

A

And individual possesses two identical alleles for a particular gene

5
Q

What is heterozygous ?

A

Individual possesses two different alleles for a particular gene

6
Q

What is a phenotype ?

A

The feature/characteristic of an individual, coded for by their two alleles

7
Q

What is the genotype ?

A

A combination of two alleles possessed by an individual

8
Q

What is codominance ?

A

When either allele doesn’t show dominants so another characteristic is it created

9
Q

How do we work out what phenotype something will have ?

A
• Write out the genotype :
 TT    X     tt 
• Then split the chromosomes by meiosis to form gametes
[T]  [T]    X    [t]  [t]
• Foil
• this creates the genotypes
TT Tt Tt tt
10
Q

What is the carrier ?

A

A person that does not have the disease but carries a diseased allele

11
Q

What is a pedigree diagram ?

A

To show us affected and uninfected male and females in a family tree