7.5 Study Guide

Question 1

Non-disjunction

Answer 1

the failure of the chromosomes to separate, which produces daughter cells with abnormal numbers of chromosomes

Question 2

Autosome

Answer 2

one of the numbered chromosomes, as opposed to the sex chromosomes

Question 3

Sex Chromosome

Answer 3

a type of chromosome involved in sex determination
XY or XX

Question 4

How many of each chromosome type should a normal gamete have?

Answer 4

1 from mom and 1 from dad

Question 5

What fails to separate if non-disjunction occurs in meiosis I?

Answer 5

homologous chromosomes

Question 6

What fails to separate if non-disjunction occurs in meiosis II?

Answer 6

sister chromaids

Question 7

Why are humans more tolerant of extra sex chromosomes than autosomes?

Answer 7

most likely relates to both X inactivation and to the small number of genes on the Y chromosome

Question 8

What determines a humans biological sex at birth will be male or female?

Answer 8

The presence of a y chromosome