Ecology connect

Select all that apply What were the main outcomes of the experiments performed by Griffith (1928)?

1) He found that living smooth-type bacteria killed mice 2) He found that a mixture of living rough-type and dead smooth-type bacteria killed mice 3) He found that living rough type bacteria did not kill mice

Consider a piece of double-stranded DNA that is 2,000 base pairs in length. If this piece of DNA had a total of 600 deoxyadenosine monophosphate nucleotides, how many deoxycytidine monophosphate nucleotides would be present? [When a nucleoside triphosphate is incorporated into DNA, it loses two phosphates to form a monophosphate.]

1400

The structure of the DNA double-helix was discovered in the year .

1953

When was the structure of the DNA double-helix discovered?

1953

How many chromosomes and sets of chromosomes are found in a normal human somatic cell?

2 sets of 23

How many hydrogen bonds form between adenine and thymine, and between guanine and cytosine?

2, 3

When adenine base pairs with thymine, hydrogen bonds form, and when cytosine base pairs with guanine, hydrogen bonds form.

2, 3

If one strand of DNA has the sequence 5'-TTCCTAGATG-3', the sequence of the bases on the complementary strand of DNA would be ______.

3' AAGGATCTAC 5'

If one strand of DNA has the sequence 5'-ATGCTACATA-3', what would be the sequence of the bases on the complementary strand of DNA?

3' TACGATGTAT 5'

A single turn of the DNA double-helix has a length of nm.

3.4

How long is a single turn of the DNA double-helix?

3.4

Place a number in the blank: A normal human somatic cell has a total of chromosomes.

46

Consider a piece of double-stranded DNA in which each strand of the helix has 1,800 nucleotides. If the piece of double-stranded DNA had a total of exactly 600 deoxycytidine monophosphate nucleotides, how many deoxyguanosine monophosphate nucleotides would be present? [When a nucleoside triphosphate is incorporated into DNA, it loses two phosphates to form a monophosphate.]

600

RNA often forms double-stranded structures. When RNA is double-stranded, the base-pairing rules are slightly modified when compared to those seen in DNA. Match the base on the left, with the base it would pair with on the right. If one of the bases isn't found in RNA, indicate that using the appropriate label on the right.

A matches Choice, U U matches Choice, A G matches Choice, C C matches Choice, G T matches Choice, Isn't found in RNA Isn't found in RNA

What kind of cell would contain linear chromosomes found in sets and located in a nucleus?

A eukaryotic cell

Select all that apply What are the three parts of a nucleotide?

A nitrogenous base A pentose sugar At least one phosphate group

What is an intron?

A non-coding sequence of DNA found within a gene

What is a nucleoid?

A region in a bacterial cell where the compacted chromosome is located

When two strands of DNA in a double helix run in opposite directions, one 5' to 3' and the other 3' to 5', what is this called?

Antiparallel

Where on the chromosome are telomeres located?

At both ends of the chromosome

The DNA double helix can adopt two conformations. The conformation that is most abundant in living cells is called ______ DNA.

B

DNA can adopt two different conformations. Which is the most abundant conformation seen in living cells?

B DNA

Select all that apply There are two conformations of DNA: B DNA and Z DNA. What are the main structural features of B DNA?

Bases are aligned perpendicular to the central axis of the molecule 10 base-pairs per turn

Select all that apply Which of the statements below correctly describe the structure of a DNA double helix?

Bases on opposite strands are hydrogen bonded together DNA strands form a helical structure

Chargaff's rule states that, "in a piece of double-stranded DNA, the amount of equals the amount of thymine and the amount of cytosine equals the amount of ."

Blank 1: adenine or A Blank 2: guanine or G

When comparing the structural features of RNA with the structural features of DNA, DNA uses the sugar and RNA uses the sugar .

Blank 1: deoxyribose Blank 2: ribose

DNA nucleotides have three main parts to their structure: at least one group; a nitrogenous ; and a 5 carbon sugar called .

Blank 1: phosphate or P Blank 2: base or bases Blank 3: deoxyribose or pentose

The constant diameter of the double helix is ensured because hydrogen bonding is always between a base (A and G) and a base (T and C).

Blank 1: purine, purines, or purine base Blank 2: pyrimidine, pyrimidines, or pyrimidine base

The structure of DNA that Crick and Watson proposed has (number) strands of DNA that are wrapped around each other to form a double helix. The DNA bases of each strand of DNA point towards the central axis of the molecule and are held together by bonds.

Blank 1: two or 2 Blank 2: H, hydrogen, Hydrogen, or h

With a few exceptions, what is the general structure of bacterial chromosomes?

Circular

Select all that apply What are the names of the different types of nucleic acids?

DNA RNA

Select all that apply How can nucleotides found in DNA be discriminated from those found in RNA?

DNA nucleotides never contain uracil DNA nucleotides contain deoxyribose DNA nucleotides may contain thymine

Nucleotides are used as the fundamental repeating structural unit of ___ and ____

DNA, RNA

What kind of sugar is found in DNA nucleotides?

Deoxyribose

A chromosome that is linear, millions of base pairs long, has a centromere, two telomeres, and multiple origins of replication is from what type of cell?

Eukaryotic

If you built a ball-and-stick model of the DNA double helix, where would you place the bases?

Facing each other inside the helix

DNA sequences with a high proportion of base-pairs between and are most stable.

G, C

DNA sequences with which kind of base pairs have higher stability?

G:C base pairs

What substance needs to meet the following criteria: ability to contain the information necessary to construct an entire organism; ability to be passed from parents to offspring; ability to be replicated; contains variation?

Genetic material

What is Chargaff's rule?

In double-stranded DNA, A=T and C=G

Select all that apply What are the defining features of eukaryotic chromosomes?

Linear Present in one or more sets Found in nucleus

In a DNA double helix, where is the sugar phosphate-backbone located?

On the outside of the helix

The AT/GC base-pairing rule requires that the purines (A and G) always base-pair with the pyrimidines (T and C). Why is this?

Pairing a purine with a pyrimidine ensures a consistent diameter of the helix.

What is the name for the type of bond connecting two sugar molecules via a phosphate group in the backbone of DNA and RNA?

Phosphodiester linkage

Select all that apply What are the main structural differences between RNA and DNA?

RNA contains uracil; DNA does not contain uracil RNA is usually single-stranded; DNA is usually double-stranded RNA uses ribose as a sugar; DNA uses deoxyribose

Select all that apply How can nucleotides found in RNA be discriminated from those found in DNA?

RNA nucleotides may contain uracil RNA nucleotides don't contain thymine RNA nucleotides contain ribose

What is the sugar found in nucleotides used to make RNA?

Ribose

In 1928, Frederick Griffith did a number of experiments to identify the "transforming principle". Notably, he found that when living -type Streptococcus pneumoniae bacteria were injected into mice, they died. Also, he showed that when living -type Streptococcus pneumoniae were mixed with heat-treated smooth-type Streptococcus pneumoniae and injected into mice, the mice .

S, R, died

Approximately how large is a typical eukaryotic gene?

Several thousand to tens of thousands of base pairs

Select all that apply What are the key features of eukaryotic chromosomes?

Tens of millions to hundreds of millions of base pairs long Possess centromeres Occur in sets (e.g. diploid) Possess telomeres Linear Multiple origins of replication

Select all that apply What assumptions did Crick and Watson need to make to determine the double-stranded, helical structure of DNA?

That all nucleotides are linked together using the same kind of bond That DNA is composed of nucleotides linked together into chains

Select all that apply Chargaff found that double-stranded DNA contains approximately a 1:1 ratio of adenine and thymine, and approximately a 1:1 ratio of cytosine and guanine. What did he conclude from this observation?

That each cytosine in DNA interacts with a guanine That each adenine in DNA interacts with a thymine

What did Chargaff conclude from the observation that in double-stranded DNA, adenine is found in the same amount as thymine, and that guanine is found in equal amounts as cytosine?

That in double-stranded DNA thymine binds to adenine while guanine binds to cytosine

What does it mean for two strands of DNA to be complementary?

The bases of one strand can base-pair with the bases of the other strand

What name is given to the entire complement of genetic material in an organism?

The genome

What is the fundamental repeating structural unit of DNA and RNA?

The nucleotide

How did Hershey and Chase discriminate between DNA and protein in their experiments to show that DNA was the genetic material of bacteriophage T2?

They labeled the DNA with radioactive phosphorous and the protein with radioactive sulfur.

What does a phosphodiester bond link together?

Two sugars on adjacent nucleotides in DNA or RNA

There are several cellular processes that involve the formation of double-stranded RNA. When double-stranded RNA forms, the base A can hydrogen bond with the base , and the base C can base pair with the base .

U, G

Who, in the 1880s, were the first people to propose the idea that a chemical substance within living cells is responsible for the transmission of traits from parents to offspring?

Weismann and Nageli

When one strand of DNA in a double helix has the chemical polarity 5' to 3', and the other, running in the opposite direction, has the chemical polarity 3' to 5', then it would be said that the two strands are .

antiparallel

In a DNA double helix, the bases point towards the ______ of the helix.

center

When the bases in one strand of DNA can hydrogen bond exactly with the bases in another strand of DNA, then the two strands of DNA are said to be ______.

complementary

DNA and RNA nucleotides have three main parts, one of which is a sugar. In DNA the sugar is

deoxyribose

Telomeres are located on both of the chromosome.

ends

Sequences in an mRNA molecule that remain after splicing and which code for polypeptide are called .

exons

What is the name for the regions of an RNA molecule that code for protein and remain after splicing?

exons

True or false: There is a close relationship between the complexity of a eukaryotic organism and genome size.

false

The entire complement of genetic material in an organism is known as the .

genome

A type of protein that can bind to the DNA backbone, affecting the compaction of DNA in eukaryotic cells, is a(n) .

histone

Which proteins form ionic interactions with the negatively charged phosphates of the DNA backbone?

histones

A non-coding sequence of DNA that is found within a protein coding gene is called a(n) .

introns

When comparing bacterial and eukaryotic genomes, the bacterial genome is generally smaller and, therefore, contains ______ DNA and fewer ______.

less; genes

If we compared the amount of DNA in the genome of a eukaryote to the amount of DNA in a bacterium would generally find that there is ______ DNA in the genome of a eukaryote than in the genome of a bacterium. This means there is likely a greater number of genes in the genome of the eukaryote.

more

In the figure, the RNA molecule is folded into which type of structure?

multibranched junction

Barbara McClintock's discovery of transposable elements was assisted by her observations of unstable chromosomal locations in corn called ______.

mutable sites

DNA gyrase, or topoisomerase II, introduces ______ supercoils into DNA.

negative

Sequences found only once or a few times within a genome, including protein-encoding genes, are called or .

nonrepetitive unique

Protein-encoding genes are typically ______ sequences.

nonrepetive

In a bacterium, the region of the cytoplasm where the compacted chromosome is located is called the .

nucleoid

In a DNA double helix, where is the sugar phosphate-backbone located?

outside

If you constructed a ball-and-stick model of the DNA double helix, you would build the sugar-phosphate backbone so that it is oriented facing ______ and so that the bases were facing ______.

outwards; inwards

Hershey and Chase were able to track whether the viral DNA or the viral protein entered the host bacterium because they were able to label the viral DNA with radioactive ______ and the viral protein with radioactive ______.

phosphorus; sulfur

Select all that apply The two types of nucleic acids are known as ______ and ______.

ribonucleic acid deoxyribonucleic acid

The nucleotides used to make RNA and DNA are made from three main parts. One of those parts is a sugar molecule; in RNA the sugar molecule is called .

ribose

What is the sugar found in nucleotides used to make RNA?

ribose

There are two conformations of DNA: B DNA and Z DNA. In B DNA, the helix has a -handed twist, the bases are found inside the helix and are aligned perpendicular to the central axis of the molecule, there are 10 base-pairs per turn of the helix, and the sugar-phosphate backbone twists evenly along the axis of the helix.

right

With a few exceptions, bacterial chromosomes are in shape.

round

In many cases, variations in the of eukaryotic genomes are not related to the complexity of the species.

size

Which type of RNA structure is shown by the molecule in the figure?

stem-loop (hairpin)

What would you call the additional coils that form when a double-helix of DNA is subject to twisting forces?

supercoil

Due to the fact that the two strands of DNA in a double helix are wound around one another, twisting forces applied to the DNA double helix result in the introduction of additional coils, a process known as DNA .

supercoiling

The enzyme DNA gyrase introduces negative into DNA.

supercoils

Molecular genetics studies ______.

the structure of DNA

A typical eukaryotic gene ranges in size from several thousand to tens of of base pairs.

thousand

The experiments of Avery, MacLeod, McCarty were trying to determine the _____ in the experiments by Frederick Griffith.

transforming substance

A process that leads to the accumulation of repetitive sequences in the genome through the insertion of short DNA segments in new locations is called.

transposition

True or false: Crick and Watson assumed that the nucleotides in DNA were all linked together in linear chains, and using the same kind of bond.

true