20.2 Monogenic Inheeritance Flashcards
What is monogenic inheritance
Inheriting a single gene
Steps to performing a genetic cross
- State phenotype of both parents
- State genotype of both parents (assign letter to represent allele)
- State gametes of each parent ( circle letters)
- Use punnet square
- State proportion of genotype
- State proportion of phenotype
What is codominance
Codominance occurs when two different alleles occur for a gene both of which are equally dominant
What is a result of codominance
Both alleles of the gene are expressed in the phenotype of the organism if present
When studying codominance how is he alleles written
Large letter for gene trait
superscript letter for allele
What is a multiple allele
A gene with more than two versions of an allele
How is sex determined
Sex of the offspring can be determined by whether the sperm fertilising the egg contain y or X chromosome
What is sex linked genes
Genes carried on the sex chromosome
Difference between Y chromosome and X chromosome
Because the Y chromosome is much smaller then the X chromosome there are a number of genes in the X chromosome that males only have one copy of
What ioccurs more frequently in males and why
Characteristics caused by a recessive allele on the section of the X chromosome which is missing in the Y chromosome
Thst is because many females will also have a dominant allele present in their cells
What is haemophilia
Example of sex liked disorder
Blood clots extremely slow due to absence of protein blood clotting factor
Why are males the main suffers of haemophilia
Because If a male inherits the recessive allele that codes for haemophilia they cannot have a corresponding dominant allele present in on their Y chromosome
