Ch. 12

Question 1

What is the chromosome theory of inheritance?

Answer 1

• states that genes are located at specific loci on chromosomes
• the behavior of chromosomes during meiosis accounts for inheritance patterns

Question 2

Who was Thomas Hunt Morgan?

Answer 2

a biologist best known for experimenting with fruit flies and confirming that genes are stored in chromosomes

Question 3

What chromosomes do males and females have in an x-y chromosome system?

Answer 3

females have xx chromosomes and males have xy

Question 4

What are sex-linked genes?

Answer 4

• those located on either sex chromosome
• mostly found on the x chromosome and show distinct patterns of inheritance
• very few found on the y chromosome

Question 5

What is non-disjunction?

Answer 5

an error in cell division where members of a pair of homologous chromosomes or sister chromatids fail to separate properly

Question 6

What does monosomic mean?

Answer 6

refers to diploid cells that have only one copy of a particular chromosome instead ot the normal two

Question 7

What does trisomic mean?

Answer 7

refers to diploid cells that have 3 copies of a particular chromosome instead of the normal two

Question 8

What is polyploidy?

Answer 8

a chromosomal alteration in which the organism possesses more than 2 complete chromosome sets

Question 9

What are the four types of chromosomal aberrations?

Answer 9

1. deletion
2. duplication
3. inversion
4. translocation

Question 10

What is deletion?

Answer 10

occurs when a chromosome breaks and some genetic material is lost

Question 11

What is duplication?

Answer 11

occurs when one or more copies of a DNA segment is produced

Question 12

What is inversion?

Answer 12

occurs when a segment breaks off and reattaches within the same chromosome, but in reverse orientation

Question 13

What is translocation?

Answer 13

occurs when a piece of one chromosome breaks off and attaches to another chromosome