7. Inheritance and Advising Flashcards
What % of males of CV defect?
8%
Each cell has 23 pairs of chromosomes, describe the distribution?
22 pairs of autosomes and 1 pair of sex chromosome.
Red- green defect is what type of inheritance defect?
X- linked recessive
Photopigments that detect light for M & L pigments are carried in which chromosome?
X Chromosome
Meaning of gene?
This is the location on a chromosome
Humans are diploid, what does that mean?
Humans have 2 of each chromosome
What is meant by allele?
This is a variant of a gene
What is meant by homozygous?
Two identical alleles
What is meant by heterozygous?
Two different alleles.
And the expression of the phenotype depends on which allele is dorminant.
What is meant by phenotype?
This is an expression of a gene- for example blue or brown eyes.
In case of parenting crosses: describe how the alleles would be if: 1) Father is colour deficient. 2) Mother is colour deficient?
1) XY Chromosome of father- the X chromosome is defective.
2) XX chromosome in females: both X chromosomes are defective.
How are men and women affected by tritanopia?
Effects male and females equally.
For tritanopia- the dominant defect is carried on?
Chromosome 7- only 1 parent needs to have defect and the child will inherit it.
(Dominant defect)
Rod monochromacy is carried on?
Chromosome 3 (recessive).
It is carried on autosome and not sex chromosome.
How do you respond to parents that ask: “Could my child be colour blind?”
You need to know family history to answer this question.
