Genetics Smartbook 2

Arrange the steps involved in fluorescence in situ hybridization (FISH) in the correct order starting at the top.

1. Obtain cells in metaphase stage of mitosis 2. Drop cells on a slide and treat them with agents that cause them to burst. 3. Denature chromosomal DNA 4. Hybridize chromosomal DNA to single-stranded DNA probes that are tagged with a fluorescent label 5. view with a fluorescence microscope

Referring to the figure, match the name of the YAC vector component on the left with its function on the right. 1. ARS 2. Centromere 3. Telomere 4. TRP 5. Foreign DNA

1. Origin of replication 2. Allows for proper chromosome segregation 3. Prevents chromosome degradation 4. Selectable marker 5. Cloned DNA to be transferred

What length of DNA is associated with a nucleosome core?

160 base pairs

What is an artificial chromosome?

A cloning vector that can accept large DNA inserts and be passed on like a chromosome in a living cell

Which of the following describes the nucleic acid molecule(s) found in a single eukaryotic chromosome (or a chromatid if the chromosome has been replicated)?

A single, long, linear molecule of double-stranded DNA

In a nucleosome,

Center= core histones around center= linker DNA under linker DNA= H1

What is the name of the complex of DNA and protein found within eukaryotic chromosomes?

Chromatin

centromere

Chromosome location where kinetochore forms Chromosome location where kinetochore forms

Choose the three main constituents of chromatin (each makes up about a third of chromatin).

DNA Histones Nonhistone proteins

Chromatin is the complex of __ & __ found within eukaryotic chromosomes

DNA protein, polypeptide, histones, or proteins

Of the five histone proteins, four are assembled into the nucleosome core but the fifth histone, called ___ is located outside the core

H1

The nucleosome core includes two each of four histones named ___,___,___,___

H2A H2B H3 H4

Which are the core histones of the nucleosome?

H3 H2A H4 H2B

Working with protein extracts from African frog eggs, scientists have been able to disassemble and reassemble metaphase chromosome. Which of the following proteins were sufficient for chromosome assembly in vitro?

Histones Condensins Histone chaperones DNA topoisomerase II

Which features are found in a Yeast Artificial Chromosome (YAC)?

Large fragment of foreign DNA Telomere Selectable marker Origin of replication Centromere

Which features are found in a Yeast Artificial Chromosome (YAC)?

Origin of replication Large fragment of foreign DNA Telomere Selectable marker Centromere

In addition to DNA and proteins, chromatin seems to contain a significant amount of chromatin-associated. ____ whose roles are not well understood.

RNA

Telomere

Structure at the end of a linear chromosome

In a nucleosome, what is the nature of the chemical attraction between the histone proteins and the DNA?

The basic histone proteins are attracted to the phosphate groups along the DNA backbone.

Scientists have been able to generate a yeast strain that has a single giant chromosome. Choose all features of this cell.

The giant chromosome has two telomeres. The giant chromosome has a single centromere.

Select all proteins that form the core of a nucleosome.

Two H2A Two H3 Two H4 Two H2B

What is the composition of the nucleosome core?

Two H2A, two H2B, two H3, two H4

Immediately after it is synthesized, a synthetic yeast chromosome contains _____.

all of the genes present on the corresponding yeast chromosome

A cloning vector that can accommodate a large DNA insert and behave like a chromosome when it is inside a living cell is called a(n) ___ chromosome

artificial or YAC

In situ hybridization can be used to localize a gene of interest due to the ability of a cloned DNA sequence to hybridize to a chromosome through

complementary base pairing

DNA in chromosomes forms long loops by passing twice through ring-shaped protein complexes known as ____

condensins

Protein, ring-shaped complexes that form loops during the compaction of DNA in chromosomes, are called ______.

condensins

During FISH, chromosomal DNA is made single-stranded by a process called ___. he single-stranded DNA is then hybridized to a single-stranded DNA___ tagged with a fluorescent label

denaturing probe

A method used to identify the locations of specific DNA sequences on chromosomes displayed in a karyotype is called ______.

fluorescent in situ hybridization (FISH)

Scientists have generated a yeast with a single giant chromosome. To do that, they ______

fused all normal yeast chromosomes and removed all but one centromere and two telomeres

A synthetic yeast chromosome ______.

is entirely human-made in a DNA synthesizer machine

During in situ hybridization, a DNA probe made from a cloned gene binds to ______.

its complementary sequence on a particular chromosome

Each nucleosome is connected to the next one by _____.

linker DNA that is about 40 bp long

Fluorescent in situ hybridization (FISH) is a method used to ______.

locate specific DNA sequences on chromosomes displayed in a karyotype

Q arm

long arm of chromosome

In a nucleosome, the DNA can associate with the histone proteins because the DNA has a ____ charge and the histone proteins have a ___ charge.

negative positive

Before DNA replication, all eukaryotic chromosomes contain

one linear, double-stranded DNA molecule

Histone H1 is found ______.

outside the nucleosome core

P arm

short arm of chromosome