Lesson 8: Chromosomal Mutations

Question 1

Non-disjunction

Answer 1

-An accident of Meiosis or Mitosis in which a tetrad (in Meiosis) or a pair of sister chromatids (in Mitosis) fail to separate properly
—often non-disjunction results in breaking chromosome

Question 2

Breaking chromosomes results in 4 types of chromosome mutation- 1: deletion

Answer 2

A chromosomal fragment is lost

Question 3

Breaking chromosomes results in 4 types of chromosome mutation- 2: Duplication

Answer 3

A chromosomal fragment from one chromosome reattaches to it homologous chromosome creating a duplicate sequence

Question 4

Breaking chromosomes results in 4 types of chromosome mutation- 3: Inversion

Answer 4

A chromosomal fragment reattached to its original chromosome in the reverse direction

Question 5

Breaking chromosomes results in 4 types of chromosome mutation- 4: translocation

Answer 5

A chromosomal fragment is attached to a non-homologous chromosome (random chromosome)

Question 6

When non-disjunction affects the entire chromosome: aneuploidy

Answer 6

—> an abnormal chromosome number
- non-disjunction can result in an entire chromosome or chromosomes that fail to separate in meiosis which will leave gametes formed w either too many or too few chromosomes

Question 7

aneuploidy- trisomy

Answer 7

A gamete has inherited a third copy of a chromosome

Question 8

aneuploidy - monosomy

Answer 8

A gamete has inherited a single copy of a chromosome

Question 9

Karyotype

Answer 9

A karyotype is an illustration or photograph of the chromosomes in the somatic cell of an organism

Question 10

Karyotype analysis p1

Answer 10

To differentiate chromosomes, they must be stretched to expose their unique banding pattern. Size and banding patterns are then used to match them.

Question 11

Karyotype analysis p2

Answer 11

Homologous chromosomes are organized from largest to smallest, with sex chromosomes last.A karyotype can also be used to establish the sex of an individual who has a chromosomal abnormality.

Question 12

Trisomy 21

Answer 12

-also know as Down’s syndrome
—> an extra chromosome is found in
position 21

Question 13

Turner syndrome

Answer 13

-results when a person inherits a single X chromosome and no Y chromosome
-this idv is an infertile female

Question 14

Klinefelter Syndrome

Answer 14

-Occurs when two copies of the X chromosome and a Y chromosome are inherited
-this idv is a sterile male