chromosomes

Question 1

chromatin

Answer 1

DNA and associated proteins ( histones and nonhistone proteins )

Question 2

chromatid

Answer 2

one of the two identical halves of a chromosome that has been replicated in preparation for cell division

Question 3

centromere

Answer 3

where the chromatids join in

- highly condenced region

Question 4

telomere

Answer 4

a region of repetitive DNA sequences at the end of a chromosome

Question 5

homologous chromosomes

Answer 5

chromosomes containing identical genetic loci although possibly different allelic forms

Question 6

chromosome

Answer 6

structure in the cell nucelus containg nuclear DNA together with a number of proteins

we ca obly see chromsines during cell repliction i.e. during mitosis or meiosis

Question 7

diploid

Answer 7

the presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair

Question 8

haploid

Answer 8

the presence of a single set of chromosomes in an organism’s cells

Question 9

mitosis

Answer 9

type of nuclear division by which two daughter cells are produced from one parent cell, with no change in chromosomal number

parent cell ( 1 x 2n )
- DNA replicates
two daugheter cells( 2 x 2n )

cell devision in non-reproductive cells

yields complete replica of the DNA in the original cell

Question 10

meiosis

Answer 10

type of nucelar division associated with sexual reproduction, producing 4 haploid (n) from a single diploid (n)

production of reproductive cells ( gametes )

yields a random mix of one of each chromosome in the original cell

Question 11

chiasma

Answer 11

the cross-shaped configuration produced during crossing over

Question 12

recombination

Answer 12

process by which pieces of DNA are broken and recombined to produce new combinations of alleles

Question 13

autosome

Answer 13

a type of chromosome found in all cells not involved with sex determination

Question 14

gonosomes

Answer 14

sex chromosomes

Question 15

ploidy

Answer 15

the number of sets of chromosomes in a cell

notation - n
haploid = n
diploid = 2n
polyploid = anything with more than 2 sets

Question 16

haplodiplois species

Answer 16

one sex has haploid cells and the other has diploid cells.

the haploid sex develops from unfertilized eggs, the diploid from fertilized eggs

Question 17

autopolyploids

Answer 17

an individual or strain whose chromosome complement consists of more than two complete copies of the genome of a single ancestral species.

formed through doubling

Question 18

allopolyploids

Answer 18

polyploid produced from a hybrid between two or more species and so possessing 2 or more unlike sets of chromosomes

( polyploid - having 2 or more chromosome sets )

Question 19

karyotype

Answer 19

image of an individuals complete set of chromosomes