lecture 19

Question 1

what is the study of cells called?

Answer 1

cytology

Question 2

what is the arrangement of chromosomes by size called?

Answer 2

karotype

Question 3

what are the two types of changes in chromosomes number?

Answer 3

euploidy and aneuploidy

Question 4

what is euploidy?

Answer 4

changes in the number of whole chromosome sets

Question 5

what is aneuploidy?

Answer 5

changes in the number of parts of chromosome sets

Question 6

what does polyploidy mean?

Answer 6

more than two set of chromosomes(abnormal)

Question 7

what is the difference between haploid and monoploid?

Answer 7

haploid refers to the number of chromosomes that a gamete has after meiosis, which contains half of genetic information
monoploid, however, means that each cell in the individual has the haploid number of chromosomes which results in a generally sterile organism

Question 8

as the chromosome number of plant increases(e.g. 2N to 8N), what happens to the plant’s size?

Answer 8

increases

Question 9

what is colchicine?

Answer 9

microtubule inhibitor

Question 10

what is spectral karotyping(SKY)?

Answer 10

takes single-stranded fluorescently-labeled DNA probes to identify unique regions of the chromosome

Question 11

what limits the number of chromosome sets in polyploidy?

Answer 11

size of the nucleus

Question 12

how does colchicine cause plants to become bigger?

Answer 12

colchicine prevents microtubules from pulling apart cells during anaphase, thereby stopping cell division

Question 13

what are autopolyploids?

Answer 13

having more than one set of chromosomes originating within a species
- ex. strawberries

Question 14

how do autopolyploids go from a parent that has a chromosome number of 2n = 6 to offspring that is a tetraploid with a chromosome number of 4n = 12?

Answer 14

meiotic error occurs, each gametes has six chromosomes like the parent, allowing the gametes to self-fertilize
- ex. white sturgeon fish

Question 15

how do autopolyploid triploid organisms occur?

Answer 15

a gamete(2n) that didn’t divide properly(meiotic error at meiosis I) fuses with a normal gamete(n) resulting in a zyote that is 3n
- often caused by non-disjunction
- ex. oysters, watermelon, bananas

Question 16

how do you know if non-disjunction occured in Meiosis I or Meiosis II?

Answer 16

meiosis I disjunction results in 2(n+1) and 2(n-1) gametes at the end of meoisis II. meiosis II disjunction results in 2(n) and 1(n-1) and 1(n+1) gametes at the end of meiosis II.

Question 17

what are hybrids of two different species with more than one chromosome set?

Answer 17

allopolyploids

Question 18

how many chromosomes does a fertile polyploid have?

Answer 18

the number of chromosome of each of the parents combined(i.e., “chromosome doubling”)