Chapter 5

Question 1

nucleotide subunits within a DNA strand are held together by ______ bonds that link the ___ end of one sugar with the ____ end of the next

Answer 1

phosphodiester
5’
3’

Question 2

double helix is held together by ______

Answer 2

hydrogen bonds

Question 3

two strands of the helix run _____ to each other

Answer 3

antiparallel

Question 4

chromatin

Answer 4

complex of DNA and protein

Question 5

maternal and paternal versions of each chromosome are called ______

Answer 5

homologous chromosomes

Question 6

the only nonhomologous chromosome pairs in humans are the _______

Answer 6

sex chromosomes in males

Question 7

karyotype

Answer 7

an ordered display of the full set of chromosomes of a cell, arranged with respect to size and number

Question 8

gene

Answer 8

segment of DNA that contains the instructions for making a particular protein or RNA molecules

Question 9

genome

Answer 9

total genetic information carried by a complete set of the chromosomes present in a cell or organism

Question 10

what happens during interphase

Answer 10

DNA replication takes place

Question 11

replication origin

Answer 11

the site where DNA replication begins

Question 12

telomeres

Answer 12

repetitive nucleotide sequence that caps the ends of linear chromosomes
protective cap

Question 13

centromere

Answer 13

allows duplicated chromosomes to be separated during M phase

Question 14

nuclear lamina

Answer 14

protein meshwork that supports the nuclear envelope

Question 15

nucleolus

Answer 15

large structure within the nucleus where ribosomal RNA is transcribed and ribosomal subunits are assembles

Question 16

histones

Answer 16

one of a small group of abundant, highly conserved proteins around which DNA wraps to form nucleosomes, structures that represent the most fundamental level of chromatin packing

Question 17

complex formed by histone and nonhistone chromosomal proteins and nuclear DNA is called _____

Answer 17

chromatin

Question 18

nucleosomes convert the _____ in an interphase nucleus into a _____

Answer 18

DNA molecules
chromatin fiber

Question 19

the _____ charges help the histones bind tightly to the _____charged sugar-phosphate backbone

Answer 19

positive
negatively

Question 20

SMC Ring Complex

Answer 20

large ring-shaped structure that contains two Structural Maintenance of Chromosome (SMC) protein subunits at its core

Question 21

the SMC ring complex that organizes the structure of interphase chromosomes is called _____

Answer 21

cohesion

Question 22

condensin

Answer 22

ring-shaped SMC protein complex that compacts duplicated chromosomes for segregation by forming both loops and loops within loops

Question 23

When are chromosomes in their most compact form?

Answer 23

during mitosis

Question 24

Which statement is true about the association of histone proteins and DNA?
-histone proteins form H-bonds with the nucleotide bases of DNA
-each histone protein has a deep groove into which a DNA double helix tightly fits
-histone proteins have a high proportion of negatively charged amino acids, which bind tightly to the positively charged DNA backbone
-histone proteins have a high proportion of positively charged amino acids, which bind tightly to the negatively charged DNA backbone

Answer 24

histone proteins have a high proportion of positively charged amino acids, which bind tightly to the negatively charged DNA backbone

Question 25

_________ can use the energy of ATP hydrolysis to change the position of nucleosomes on the DNA

Answer 25

chromatin-remodeling complexes

Question 26

histone-modifying enzyme

Answer 26

enzyme that catalyzes the covalent addition of a small molecule to a specific amino acid side chain on a histone

Question 27

heterochromatin

Answer 27

highly condensed region of an interphase chromosome

Question 28

euchromatin

Answer 28

one of the two main states in which chromatin exists within an interphase cell
prevalent in gene-rich areas, its less compact structure allows access for proteins involved in transcription

Question 29

any genes packaged into heterochromatin tend to be ______ because _____

Answer 29

silenced
it is so compact

Question 30

epigenetic inheritance

Answer 30

transmission of a heritable pattern of gene expression from one cell to its progeny that does not involve altering the nucleotide sequence of the DNA

Question 31

Where is heterochromatin NOT commonly located?
-centromeres
-the human X chromosome
-gene-poor chromosomal regions
-chromosomal regions carrying gene that encode ribosomal proteins

Answer 31

chromosomal regions carrying genes that encode ribosomal proteins