Unit 2 Genetics

In simple transposition __________________

a double-stranded piece of DNA is moved from one site to another.

When an F factor integrates into the chromosome, it creates

a high frequency of recombination (Hfr) cell.

An advantage of negative supercoiling in bacteria is that

it promotes strand separation in small regions enhancing DNA replication and transcription.

The two strands of DNA are antiparallel, meaning that

the two strands have opposite orientation of their 5′ and 3′ ends.

During _____, a portion of a bacterial chromosome is transferred to a recipient cell via a _____.

transduction; bacteriophage

During reproduction, there is ____________ of the genetic material from parents to offspring.

transmission

Genetic material must have ___________ that can account for phenotypic differences within each species.

variation

Which bacterial genetic transfer process does NOT require recombination with the bacterial chromosome?

F+ x F- conjugation

Because they contain nucleic acid and reproduce, most virologists consider viruses as living organisms. T/F

False

Centromeres contain specialized sequences located at both ends of the linear chromosome

False

Eukaryotic chromosomes contain a telomere that forms a recognition site for the kinetochore proteins. T/F

False

All viruses use DNA as their genetic material. T/F

False-some use RNA

A typical eukaryotic chromosome is about one hundred thousand base pairs in length. T/F

False. has tens of millions-hundreds of millions bp in length

Eukaryotic chromosomes are usually circular. T/F

False.contains a linear DNA molcule

Natural transformation

A natural process that has evolved in certain bacteria in which they can take up extracellular DNA

Highly repetitive sequences

-Alu -Centromeric tandem arrays

Unique sequences

-structural genes -exons which encode polypeptides -intron sequences

What is the product of DNA replication

2 daughter DNA molecules

What would have been the result of the Hershey Chase experiment if proteins, rather than DNA, were the genetic material?

35S would have been found inside the bacterial cells.

An inverted repeat on an insertion element has the sequence 5'-AGTCAT-3'. What will be the sequence of the inverted repeat at the end of the insertion element on the same strand?

5'-ATGACT-3'

fertility plasmid

Allow bacteria to mate/conjugate with each other

Artificial transformation

An unnatural process in which the bacterial cells are forced to take up DNA

Which form of DNA is the predominant form found in living cells?

B DNA

Competence factors

Bacteria that can take up DNA naturally carry genes that encode these type of proteins

Competent cells

Bacterial cells that are able to take up DNA

Virulence plasmids

Carries genes that turn a bacterium into a pathogenic strain

Resistance plasmids

Contain genes that confer resistance against antibiotics and other types of toxins

Col-plasmids

Contain genes that encode colicins, which are proteins that kill other bacteria

What part of the T2 phage enters the bacterial cell following infection? Multiple Choice

DNA

Hershey and Chase

Determined that the genetic material of T2 phage is DNA. -used radioisotopes to distinguish proteins from DNA

Avery, MacLeod, and McCarty

Discovered that DNA is the substance that transforms bacteria.

Components of DNA molecules

Nitrogenous base, phosphate group, deoxyribose

Weismann and Nägeli

Proposed that a chemical substance within living cells is responsible for the transmission of traits from parents to offspring.

Griffith

Showed that the genetic material from type S bacteria could transform type R bacteria into type S.

Nonhomologous recombination

The process by which DNA that is not similar to a region of DNA in the bacterial chromosome is incorporated into the bacterial chromosome

Homologous recombination

The process by which DNA that is similar to a region of DNA in the bacterial chromosome is incorporated into the bacterial chromosome

The process of forming RNA from a template strand of DNA is called__________

Transcription

A typical eukaryotic chromosome contains between a few hundred and several thousand different genes. T/F

True

Eukaryotic chromosomes contain many origins of replication that are interspersed about every 100,000 base pairs. T/F

True

In horizontal gene transfer, DNA can be acquired from the same species or from a different species. T/F

True

In simple transposition, the transposable element ends up between two direct repeats of the target sequence. T/F

True

Many eukaryotic species are diploid with two sets of chromosomes in somatic cells. T/F

True

Phage T2 infection of a bacterial cell is accompanied by degradation of host cell DNA. T/F

True

The term phage is an abbreviation of the word bacteriophage. T/F

True

Mature T2 phage particles are released

after lysis of the bacterial host cell.

The protein coat that surrounds the genetic material of the T2 phage is termed the

capsid

Degradative plasmids

carry genes that enable the bacterium to digest and utilize an unusual substance

Which form of bacterial gene transfer requires direct contact between two cells?

conjugation

Simple transposition is also called ________ transposition.

conservative

The genetic material must contain the __________ necessary to construct an entire organism.

information

Moderately repetitive sequences

rRNA genes

The__________of genetic material allows it to be passed from parents to offspring, and from a mother cell to daughter cells.

replication