Question

Please help?? How many and what type of chromosomes would be expected in a karyotype of a human male?
1. 22 pairs of autosomal chromosomes and 2 Y chromosomes
2. 23 pairs of autosomal chromosomes and 2 Y chromosomes
3. 22 pairs of autosomal chromosomes, 1 X chromosome, and 1 Y chromosome
4. 23 pairs of autosomal chromosomes, 1 X chromosome, and 1 Y chromosome
Which of the following pairs of genotypes result in the same phenotype?
1. IAIA and IAIB
2. IBIB and IBi
3. IBIB and IAIB
4. IBi and ii

Answer 1

for the first one you need to remember the diploid number is 46. Out of them two are determining the sex either XX for woman or XY for men;
For the second capital stands for a dominant allele.

Answer 2

I still can't really figure it out

Answer 3

so you have 44 autosomal chromosomes. that makes 22 pairs then a male is XY.
For the second you need to find pairs for which the capital letter make a similar combinaison. the first one for example the left proposition will express IA when the right will express IAB.
clearer like that?

Answer 4

Yeah it is thank you! Can you help me with this last one?
For the pedigree in Figure 14–6, shaded symbols represent afflicted people. Males are squares; women are circles. If the trait is a sex-linked trait carried on the X chromosome, what is true about the mother represented by circle 1?
She has two alleles for the disorder.
She has one allele for the disorder.
She has no alleles for the disorder.
She has the genotype XXY.

Answer 5

. The mother in circle 1 (also true for 6) caries the allele for the disease but does not have the disease. As the disease is not seen at all generations it indicates a recessive allele is leading to the disease. So she must have another non-mutated allele.