Inheritance questions Flashcards
What is meant by codominence
When both alleles are expressed by phenotype
Male cats with a tortoiseshell phenotype do not usually occur. Explain why.
Males only posses one allele
-can’t be reccesive
Some breeders only breed for the dominant allele, what would happen to the alleles
- increase of homozygous dominant
- decrease of homozygous recessive
Some scientists use the restriction enzyme on each dn strand
Cut at same base sequence
So all code for R
Explain what it means for genes to be linked
They have 2 alleles on the same chromosome
Use your knowledge of gene linkage to explain the results
975, 963,186,194
On GgNn
-mainly Gn and gn produced
-when crossed over few Gn and gN
-so few ggNn
Explain the advantage of presenting results as a ratio?
- allows to validly compare
give 2 causes of genetic variation
- crossing over
-random fusion of gametes
-random fertilisation
Do autosomal alleles cross over
no
Why arnt the observed phenotype ratios not the same as expected
-random fertilisation
-small sample size