Cytogenetics

Question 1

Refers to the presence of three or more haploid sets of chromosomes

Answer 1

Polyploidy

Question 2

Usually not viable. Inability to synapse and form tetrads impairs meiosis

Answer 2

Animal Polyploidy

Question 3

Plant Polyploidy: sometimes these are viable because plants can use ___ chromosomes are copied, but a cytoplasmic division does not occur

Answer 3

Somatic doubling

Question 4

All chromosome sets from the same species (double fertilization)

Answer 4

Autopolyploidy

Question 5

Two different species contribute to the extra chromosomes

Answer 5

Allopolyploidy

Question 6

Failure to separate

Answer 6

Non-disjunction

Question 7

The process of meiosis in mammalian females is halted until the onset of ___

Answer 7

Puberty

Question 8

The result of non-disjunction of homologous chromosomes during meiosis

Answer 8

Aneuploidy

Question 9

Half missing a chromosome

Answer 9

Monosomy

Question 10

If non-disjunction occurs during ___, all four gametes are defective

Answer 10

Anaphase I

Question 11

Half have an extra chromosome

Answer 11

Trisomy

Question 12

If non-disjunction occurs during ____, half of the gametes would be normal

Answer 12

Anaphase II

Question 13

___ leads to spontaneous abortion

Answer 13

Autosomal Monosomy

Question 14

Most ___ leads to spontaneous abortion

Answer 14

Autosomal Trisomy

Question 15

___ causes Patau Syndrome

Answer 15

Trisomy 13

Question 16

___ causes Edwards Syndrome

Answer 16

Trisomy 18

Question 17

___ causes Down Syndrome

Answer 17

Trisomy 21

Question 18

Mental development stalls at 6 month stage; small or fused eyes, cleft palate, kidney and heart abnormalities

Answer 18

Patau Syndrome

Question 19

Mental development stalls at 6 month stage; heart and liver defects; clenched fists

Answer 19

Edwards Syndrome

Question 20

Mild to moderate mental retardation; short stature, broad hands, epicanthal eyelids

Answer 20

Down Syndrome

Question 21

Female: Karyotype is 45, XO
Short, less breast tissue, infertile (amenorrhea)
No Barr bodies

Answer 21

Turner’s Syndrome

Question 22

Male: Karyotype is 7, XXY
Tall, less body hair, less muscular, infertile
1 Barr Body

Answer 22

Klinefelter’s Syndrome

Question 23

Errors of crossing over

Answer 23

Structural Aberrations

Question 24

Chromosome breaks, reattaches in the wrong place. Results include chromosomes with 2 copies of the same allele or missing an allele

Answer 24

Deletions and Duplications

Question 25

A segment of a chromosome reattaches in a “flipped” orientation

Answer 25

Inversions

Question 26

Recombination (crossing over) between non-homologous chromosomes

Answer 26

Translocations

Question 27

The centromere is not included in inverted segment

Answer 27

Paracentric Inversions

Question 28

The centromere is included within the inverted segment

Answer 28

Pericentric Inversions

Question 29

___ and ___ contain gene deletions and duplications

Answer 29

Acentric and Dicectric

Question 30

__ cannot attach to the spindle during cell division, so it eventually gets lost, leading to aneuploidy

Answer 30

Acentric

Question 31

___ requires formation of a translocation heterozygote

Answer 31

Synapsis