T5M3 Flashcards
How many pairs of chromosomes in a human cell?
23
The pairs of chromosomes in a human cell consists of how many base pairs of DNA?
over 3 billion
How many protein coding genes in human genome?
estimated over 20 000
More than one gene per chromosome: yes or no?
yes
Alleles are linked on a single chromosome meaning they must
unlink and recombine in different ways
How many types of sex chromosomes? What are they?
2, X and Y
How many genes on Y chromosome? Code for how many proteins?
78, code for 25 proteins (half sex)
Non Homologous
almost none of the genes in the X chromosome have counterparts in Y chromosome
Sex linked gene
a gene on either sex chromosome, expression of phenotype depends on sex of individual
Do Mendel’s principles of inheritance apply to genes on X an Y?
no, did not observe in pea plants they have no sex
Ishihara colour test
red-green colorblindness, circle filled with dots
Women that are colour blind genotype
homozygous for the color blind allele
Male colour blind genotype
receives recessive colour blind allele from mother
Hemizygous individual
only have one locus for this allele, rule of dominance and recessiveness no longer apply
Hemizygous individual
only have one locus for this allele, rules of dominance and recessiveness no longer apply