2. Simple Monohybrid Crosses Flashcards
Are gametes haploid or diploid
Haploid
They contain only one allele for each gene
What happens when haploid gametes fuse together ?
The alleles they contain form the genotype of the diploid offspring
Why are genetic diagrams used?
They show how alleles are passed on to next generation.
And they predict genotypes and phenotypes of the offspring.
Monohybrid inheritance
Is the inheritance of a characteristic controlled by a single gene.
Monohybrid crosses
Show the likelihood of the different alleles of that gene (different versions of the characters) being inherited by offspring.
First set of offspring
F1 generation
What will a monohybrid cross with 2 homozygous parents always produce ?
ALL heterozygous offspring in F1 generation
Phenotypic ratio
Is the ratio of different phenotypes in the offspring.
Genetic diagrams allows you to predict phenotypic rations in F1 and F2 offspring
What is the typical ratio with 2 heteozygous parents?
3:1
Dominant : recessive
Example of co dominant alleles
Sickle cell anaemia
Genetic disorder caused by mutation in haemoglobin gene.
Caused by red blood cells to be sick shaped
Example.
What if the person is heterozygous for normal haemoglobin and sick cell haemoglobin?
They will have a sickle cell trait.
Some normal haemoglobin
Some sick haemoglobin
Alleles are co dominant as both expressed in phenotype.
What is typical ratio you would expect to see with 2 heterozygous patents involving co dominance .
1 : 2 : 1 ratio in offspring
If you’re asked to find probability of something. How can you write it ?
Decimal
Fraction
%