Biology Exam 1 Lecture 4

Question 1

REMEMBER Telomeres = (GGGGTTA)n

Answer 1

Telomeres = (GGGGTTA)n

Question 2

T/F:Eucaryotic chromosomes typically contain several sites where DNA replication is initiated – these are termed promoters.

Answer 2

False

Question 3

_____ and _____ are frequently the home of simple repetitive sequences

Answer 3

Telomeres, centromeres

Question 4

DNA replication is initiated at ____

Answer 4

replication origins

Question 5

The number of replication origins depends on

Answer 5

genome size

Question 6

_____ resides at replication forks

Answer 6

DNA polymerase resides at replication forks

Question 7

DNA replication occurs
_____ and is
_________

Answer 7

bidirectionally, semi-conservative

Question 8

DNA replication is
continuous on the
_______ and
is discontinuous on
the _____

Answer 8

leading strand, lagging strand

Question 9

______ and
_____ are both
used to unwind the
parental strands for
replication and to
relieve supercoiling
due to the unwinding,
respectively

Answer 9

DNA helicase, DNA gyrase

Question 10

Access to chromosomal DNA of eucaryotes for both replication and gene expression can be controlled by nucleosome dynamics. T or F

Answer 10

True

Question 11

DNA is packaged by
specific proteins into

Answer 11

chromatin

Question 12

What is the packing factor of DNA?

Answer 12

Packing factor of 10,000x !

Question 13

DNA is packaged by _____ which bind
DNA to form _____

Answer 13

histones, nucleosomes

Question 14

Chromatin Histones are rich in _____

Answer 14

basic amino acids

Question 15

DNA has what kind of backbone?

Answer 15

acidic phosphodiester backbone

Question 16

If ______ were mutated to have many acidic amino acids, DNA would no longer directly interact with them.

Answer 16

histones

Question 17

Eukaryotic chromosomal DNA is packaged by ______ proteins. DNA bound to these proteins form ______.

Answer 17

histone; nucleosomes

Question 18

True or False: Heterochromatic regions of chromosomes tend to be rich in expressed genes.

Answer 18

False

Question 19

_____ on gene expression involve
gene location relative to different chromatin environments

Answer 19

Position effects

Question 20

Genomes contain chromosomal DNAs
composed of different sequences that
vary both in complexity and their copy number.

single copy or a few copies (i.e. <10) - ____
middle repetitive – _____
highly repetitive – ____

Answer 20

genes, transposable elements, blocks of simple sequences

Question 21

Repeated regions of DNAs are often
complexed in a specific type
of highly condensed chromatin termed
______ – this can be found
at and near ____ and _____
as well as in other blocks on
chromosomes

Answer 21

heterochromatin, telomeres, centromeres

Question 22

Low copy genes and middle repetitive sequences are generally found in ____ regions of the genome.

Answer 22

euchromatic

Question 23

The nucleolus is:

Answer 23

An area of the nucleus associated with rRNA synthesis

Question 24

Organization of interphase chromosomes in the nucleus is important to

Answer 24

proper gene
expression/regulation

Question 25

Some genes such as ____ are repeated (multi-copy) and found in large blocks

Answer 25

rRNAs