Chapter 10.2: Eukaryotic Chromosomes

Question 1

Define euchromatin

Answer 1

that portion of a eukaryotic chromosome that is transcribed into mRNA; contains active genes that are not tightly condensed during interphase

Question 2

Define heterochromatin

Answer 2

the portion of a eukaryotic chromosome that is not transcribed into RNA; remains condensed in interphase and stains intensely in histological preparations

Question 3

Define haploid (n)

Answer 3

having only one set of chromosomes

Question 4

Define sister chromatid

Answer 4

one of two identical copies of each chromosome, still linked at the centromere, produced as the chromosomes duplicate for mitotic division; similarly, one of two identical copies of each homologous chromosome present in a tetrad at meiosis

Question 5

Define homologous

Answer 5

refers to a pair of the same kind of chromosome in a diploid cell

Question 6

What is having two sets of chromosomes; in animals, twice the number of characteristic of gametes; in plants, the chromosome number characteristic of the sporophyte generation?

Answer 6

diploid (2n)

Question 7

What is a protein complex that holds sister chromatids together during cell division. The loss of cohesins at the centromere allowed the anaphase movement of chromosomes?

Answer 7

cohesin

Question 8

Define nucleosome

Answer 8

a complex consisting of a DNA duplex wound around a core of eight histone proteins

Question 9

Define karyotype

Answer 9

the morphology of the chromosomes of an organism as viewed with a light microscope

Question 10

Define chromatin

Answer 10

the complex of DNA and proteins of which eukaryotic chromosomes are composed; chromatin is highly uncoiled and diffuse in interphase nuclei, condensing to form the visible chromosomes in prophase

Question 11

Define homologue

Answer 11

one of a pair of chromosomes of the same kind located in a diploid cell; one copy of each pair of homologues comes from each gamete that formed the zygote

Question 12

What is the portion of a eukaryotic chromosome that is not transcribed into RNA; remains condensed in interphase and stains intensely in histological preparations?

Answer 12

heterochromatin

Question 13

What is any of eight proteins with an overall positive charge that associate in a complex. The DNA duplex coils around a core of eight these , held by its negatively charged phosphate groups, forming a nucleosome

Answer 13

histone proteins

Question 14

What is the morphology of the chromosomes of an organism as viewed with a light microscope?

Answer 14

karyotype

Question 15

What is one of two identical copies of each chromosome, still linked at the centromere, produced as the chromosomes duplicate for mitotic division; similarly, one of two identical copies of each homologous chromosome present in a tetrad at meiosis?

Answer 15

sister chromatid

Question 16

What is one of a pair of chromosomes of the same kind located in a diploid cell; one copy of each pair of homologues comes from each gamete that formed the zygote?

Answer 16

homologue

Question 17

Define diploid (2n)

Answer 17

having two sets of chromosomes; in animals, twice the number of characteristic of gametes; in plants, the chromosome number characteristic of the sporophyte generation

Question 18

Define cohesin

Answer 18

a protein complex that holds sister chromatids together during cell division. The loss of cohesins at the centromere allowed the anaphase movement of chromosomes

Question 19

What is the complex of DNA and proteins of which eukaryotic chromosomes are composed; it is highly uncoiled and diffuse in interphase nuclei, condensing to form the visible chromosomes in prophase?

Answer 19

chromatin

Question 20

What is that portion of a eukaryotic chromosome that is transcribed into mRNA; contains active genes that are not tightly condensed during interphase?

Answer 20

euchromatin

Question 21

Define histone proteins

Answer 21

any of eight proteins with an overall positive charge that associate in a complex. The DNA duplex coils around a core of eight histone proteins, held by its negatively charged phosphate groups, forming a nucleosome

Question 22

What is a solenoid?

Answer 22

 The DNA wrapped in nucleosomes is further coiled into an even more compact structure called the solenoid

Question 23

What is having only one set of chromosomes?

Answer 23

haploid (n)

Question 24

Define mitosis

Answer 24

somatic cell division; nuclear division in which the duplicated chromosomes separate to form two genetically identical daughter nuclei

Question 25

What refers to a pair of the same kind of chromosome in a diploid cell?

Answer 25

homologous

Question 26

What is somatic cell division; nuclear division in which the duplicated chromosomes separate to form two genetically identical daughter nuclei?

Answer 26

mitosis

Question 27

What is a complex consisting of a DNA duplex wound around a core of eight histone proteins?

Answer 27

nucleosome