Lecture 1 #2

Front 1

If a stretch of human double stranded DNA contains 47% G + C, then

Back 1

it contains 53% A + T

Front 2

Proteins called transcription factors are involved in ____ of transcription.

Back 2

the initiation stage

Front 3

The semi-conservative model of DNA replication proposed that:

Back 3

Each new DNA molecule contains one old strand and one new strand.

Front 4

Suppose that a mistake made during DNA replication in a cell is not corrected, but instead the mutation remains in the single strand where it occurred. Then suppose that after the cell divides both daughter cells survive, and those cells then go on to have DNA replication and ultimately cell division. There are now four cells where there once was one cell. Assuming that the mistake was never corrected and that no new uncorrected mistakes occurred, how many of the four cells will have the mutation in their DNA?

Back 4

two

Front 5

Each DNA nucleotide is made up of

Back 5

a five-carbon sugar, a phosphate group, and one of four nitrogenous bases.

Front 6

The importance of crossing over during meiosis is

Back 6

to hold homologous pairs of chromosomes together.

Front 7

In DNA the purines are

Back 7

adenine and guanine.

Front 8

In meiosis, sister chromatids separate

Back 8

during Anaphase II

Front 9

The T2 bacteriophages used in the Hershey and Chase experiment are made of what?

Back 9

DNA and protein

Front 10

The level of control that determines which genes are copied into mRNA is called ________ regulation.

Back 10

transcriptional

Front 11

Adding nucleotides onto a growing DNA strand during DNA replication in cells occurs in

Back 11

the 5' → 3' direction only.

Front 12

Nondisjunction in Meiosis I results in

Back 12

one pole of the cell receiving neither member of a homologous pair of chromosomes.

Front 13

A ________ is a large multi-protein complex that can form a bridge between the enhancer and the promoter.

Back 13

a co-activator

Front 14

Homologous pairs of chromosomes

Back 14

consist of two chromosomes with the same genes.

Front 15

Avery, McLeod, and McCarty continued Griffith's work with S. pneumoniae and concluded from their experiments that DNA was the hereditary material. What would happen to mice after injection of heat-killed virulent bacteria mixed with live avirulent bacteria after treatment with proteinase if protein was the hereditary material instead of DNA?

Back 15

the mice would live

Front 16

Consider a mutant organism that is unable to make the amino acid arginine. Knowing that the metabolic pathway to production of arginine is ornithine → citrulline→ arginosuccinate → arginine, you test the ability of the mutant to grow in the presence of each one of these compounds, providing just one of the compounds in each of your tests.

Back 16

You find that the mutant can grow in the presence of arginosuccinate or arginine, but not in the presence of citrulline or ornithine. From this you can conclude that the product of the gene mutated in the mutant is most directly involved in production of ____.

arginosuccinate from citrulline

Front 17

When Hershey and Chase labeled viruses with radioactive phosphorus, they concluded that the virus injects DNA and not protein into its host because the

Back 17

radioactive DNA ended up inside the bacterium

Front 18

What happens when living R strain Streptococcus pneumoniae bacteria are mixed with heat-killed S strain Streptococcus pneumoniae bacteria?

Back 18

The R strain bacteria are transformed into S strain bacteria.

Front 19

In multi-cellular animals, most of the structural and functional differences in cell types are determined by differences in the ________.

Back 19

expression of specific genes

Front 20

In their experiments to determine the transforming principle, Avery, MacLeod, and McCarty used enzymes that break down ____.

Back 20

protein, DNA, and RNA

Front 21

During DNA replication what determines the sequence of the bases in the new DNA strand?

Back 21

sequence of bases in the template strand

Front 22

During transcription

Back 22

only one of the two DNA strands acts as a template.

Front 23

Adjacent nucleotides on a strand of DNA are connected to each other by a(n) ____.

Back 23

phosphodiester bond

Front 24

Why can't nucleic acids and proteins be distinguished from each other by labeling nitrogen with the 15N isotope?

Back 24

Nitrogen is found in both nucleic acids and proteins.

Front 25

In the Hershey and Chase experiment, 32P was used to label ____ and 35S was used to label ____.

Back 25

DNA; protein

Front 26

In the Meselson-Stahl experiment, bacterial DNA was labeled completely with heavy nitrogen (N-15) and then grown in the presence of light nitrogen (N-14). When only mixed DNA was observed after ONE generation of growth in N-14, what was the conclusion?

Back 26

DNA replication is either semiconservative or dispersive

Front 27

The figure above depicts the result of an experiment to determine how DNA replication occurs. Based on these results, it appears that after replication each DNA molecule is made of

Back 27

one old DNA strand and one new DNA strand.

Front 28

Wilkins and Franklin studied the structure of DNA using ____.

Back 28

X-ray diffraction

Front 29

If a normal diploid germ cell in a bird has eight chromosomes, then

Back 29

there are four chromosomes per cell after the first meiotic division and cytokinesis.

Front 30

To initiate transcription in eukaryotes, ________ bind to the promoter region and recruit the RNA polymerase.

Back 30

general transcription factors