Lesson 4: Non-Mendelian Genetics…

Question 1

Sex chromosomes

Answer 1

-the 23rd pair of chromosomes, these chromosomes determine genetic sex
-made up of combinations of X and Y chromosomes
XX = genetically female
XY = genetically male

Question 2

X and Y chromosome

Answer 2

—X chromosome is much larger than the Y chromosome and will carry a larger amount of genetic material and genes
—the genetic information on the Y chromosome is largely unknown
—the Y chromosome contains the
genes for androgens which trigger
the development of male.
reproductive organs and organs

Question 3

Sex-linked traits p1

Answer 3

-sex-linked traits are determined by allele of genes that are located on the X chromosome
the notation: X^A
X = X chromosome
A = allele of the gene

Question 4

Sex-linked traits only found in X chromosome p2

Answer 4

-Sex-linker traits are unusual because they are found on the X chromosome
-the recessive phenotype of sex-linked traits is most often observed in ppl that carry one X and one Y chromosome

Question 5

Sex-linked traits p3 genetic male

Answer 5

-genetic males only have one X chromosome and there is no corresponding allele on the Y chromosome
—as a result, the allele present on the
X chromosome inherited by the
genetic male is expressed

Question 6

Sex-linked traits p3 genetic female

Answer 6

-genetic females will inherit 2 X chromosomes so the Rules of Dominance apply
—often genetic females will ‘carry’ the
recessive trait in the heterozygous
genotype