chapter 15 Flashcards

(64 cards)

1
Q

Who isolated DNA for the first time and in what year?

A

Friedrich Miescher in 1869

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What term did Miescher coin to describe the substance he found in DNA?

A

Nucleic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the two natural forms of nucleic acids?

A
  • Deoxyribonucleic acid (DNA)
  • Ribonucleic acid (RNA)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What role does DNA play in cells?

A

Governs the processes of heredity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the role of RNA in cells?

A

Plays a role in gene expression and protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What phenomenon did Frederick Griffith discover in his 1928 experiment?

A

The transforming principle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What did Griffith use to demonstrate the transforming principle?

A

Heat-killed pathogenic bacteria and live non-pathogenic bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happened when Griffith treated heat-killed bacteria with a protein-destroying enzyme?

A

Transformation still occurred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happened when Griffith treated heat-killed bacteria with a DNA-destroying enzyme?

A

Transformation did not occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What did Hershey and Chase demonstrate in 1952?

A

DNA, not proteins, carries genetic information

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What method did Hershey and Chase use to label the components of the virus?

A

Radioactive labeling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a nucleotide?

A

The basic building block of nucleic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What components make up a nucleotide?

A
  • A sugar molecule (ribose in RNA or deoxyribose in DNA)
  • A phosphate group
  • A nitrogen-containing base
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the nitrogenous bases found in DNA?

A
  • Adenine (A)
  • Cytosine (C)
  • Guanine (G)
  • Thymine (T)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What base does RNA have instead of thymine?

A

Uracil (U)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What did Chargaff discover about nucleotide proportions in DNA?

A

Adenine equals thymine and cytosine equals guanine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Who used X-ray photography to analyze the structure of DNA?

A

Rosalind Franklin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the structure of DNA as described by Watson and Crick?

A

A double helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are complementary base pairs in DNA?

A
  • Adenine (A) pairs with Thymine (T)
  • Cytosine (C) pairs with Guanine (G)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the two types of nucleic acids discussed?

A
  • DNA
  • RNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the defining feature of RNA compared to DNA?

A

RNA is single-stranded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the definition of a gene?

A

A functional sub-unit of DNA that directs the production of one or more polypeptides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What constitutes the genome of an organism?

A

The sum of all the DNA, including genes and non-coding DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is DNA replication?

A

The process of creating an exact copy of a molecule of DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the error rate of DNA replication in human cells?
About one per billion nucleotide pairs
26
What are the three main steps of DNA replication?
* Initiation * Elongation * Termination
27
What enzyme is responsible for unzipping the DNA molecule during replication?
Helicase
28
What is the role of DNA polymerase?
Adds nucleotides during DNA replication
29
What is the role of RNA primers in DNA replication?
Serve as starting points for DNA synthesis
30
What is the process of DNA sequencing?
Identifying the precise nucleotide sequence of a DNA fragment
31
What was the first entire genome to be sequenced?
The genome of the virus θX174 in 1977
32
What is transcription?
The process by which DNA is copied into mRNA
33
What enzyme catalyzes the synthesis of RNA during transcription?
RNA polymerase
34
What is the role of mRNA in protein synthesis?
Carries the information needed for protein synthesis from the nucleus to the cytoplasm
35
What is the process by which mRNA directs the synthesis of a protein?
Translation
36
What base in RNA replaces thymine found in DNA?
Uracil ## Footnote In RNA, thymine is replaced by uracil.
37
In which direction do RNA polymerases transcribe DNA?
5' to 3' direction ## Footnote RNA polymerases transcribe only one strand of the template DNA.
38
What signals the RNA polymerases to detach from the DNA during transcription?
A specific nucleotide sequence in the template DNA ## Footnote This sequence serves as a signal to stop transcription.
39
Where is mRNA transported after transcription?
Into the cytoplasm, to the ribosome ## Footnote mRNA is formed during transcription and then transported for translation.
40
What molecule links each mRNA codon to its specific amino acid?
Transfer RNA (tRNA) ## Footnote tRNA recognizes and binds to the corresponding codon in the ribosome.
41
What is a codon?
A three-base stretch of mRNA ## Footnote One codon contains the information for a specific amino acid.
42
How does the genetic code exhibit redundancy?
More than one codon can code for the same amino acid ## Footnote This means that multiple codons can produce the same amino acid.
43
What does it mean for the genetic code to be continuous?
It reads as a series of three-letter codons without spaces, punctuation, or overlap ## Footnote Knowing where to start and stop translation is essential.
44
What is a mutation?
A permanent change in the genetic material of an organism ## Footnote Mutations can be spontaneous or induced.
45
What type of mutations affect the genetic information in an organism's gametes?
Germ line mutations ## Footnote These mutations can be passed on to offspring.
46
What are somatic cell mutations?
Mutations that occur in body cells ## Footnote These mutations are not passed on to offspring.
47
What is a point mutation?
A chemical change that affects just one or a few nucleotides ## Footnote It may involve substitution, insertion, or deletion of nucleotides.
48
What is a silent mutation?
A mutation that has no effect on the cell's metabolism ## Footnote It does not alter the polypeptide produced.
49
What is a mis-sense mutation?
A mutation that results in an altered protein ## Footnote It can be harmful, such as in sickle cell disease.
50
What is a nonsense mutation?
A mutation that renders the gene unable to code for a functional polypeptide ## Footnote This type of mutation can lead to premature termination of protein synthesis.
51
What is a frameshift mutation?
A mutation caused by insertion or deletion of nucleotides ## Footnote It alters the entire reading frame of the gene.
52
What are mutagens?
Substances or events that increase the rate of mutation ## Footnote Mutagens can be physical (e.g., x-rays) or chemical (e.g., carcinogens).
53
What is genetic engineering?
The manipulation of genetic material to alter genes ## Footnote It blends plant, animal, and bacterial DNA.
54
What is recombinant DNA?
A molecule of DNA that includes genetic material from different sources ## Footnote It is used in genetic engineering.
55
What are restriction enzymes?
Proteins produced by bacteria that cleave DNA at specific sites ## Footnote They are essential tools in recombinant DNA technology.
56
What is the purpose of the polymerase chain reaction (PCR)?
To amplify DNA sequences ## Footnote PCR can generate billions of copies of a specific region of DNA.
57
How does gel electrophoresis work?
Separates mixtures of DNA, RNA, or proteins according to molecular size ## Footnote Molecules travel through a gel under an electrical field.
58
Cytosine bonds with what?
Thymine
59
Adenine bonds with what?
Guanine.
60
What nitrogen RNA base replaces Thymine?
Uracil
61
What are Okazaki fragments?
short pieces of DNA created on the lagging strand during DNA replication. These fragments form in small sections and are later connected by an enzyme called DNA ligase.
62
What occurs when an individual receives 3 copies of chromosomes instead of the normal two?
Down Syndrome
63
What occurs when an individual inherits only a single X chromosome, and the Y chromosome is missing?
Turner Syndrome
64
what’s the name for when a man has an extra X chromosome?
Klinefelter syndrome