Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Chapter 12 - DNA & RNA > Flashcards

Chapter 12 - DNA & RNA Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Who was Frederick Griffith?

A

A British scientist who was trying to figure out how bacteria make people sick.

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

What did Griffith do to answer his question?

A

He injected mice with 4 different samples of bacteria. When injected separately, neither the heat killed disease causing bacteria nor the live harmless bacteria killed the mice. But when the 2 were combined, it caused fatal pneumonia.

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

What did Griffith call the process when the heat-killed bacteria had passed its disease causing ability to the harmless strain?

A

transformation

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

What did Griffith hypothesize from his experiment?

A

When the live, harmless bacteria and the heat-killed bacteria were mixed, some factor was transferred from the heat-killed cells into the live cells. That factor must contain info that could change the harmless bacteria into disease-causing ones.

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

What did Avery and his group discover?

A

The nucleic acid DNA stores and transmits the genetic information from one generation of an organism to the next.

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

What is a bacteriophage?

A

a kind of virus that infects bacteria (“bacteria eater”)

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

What was Hershey and Chase trying to figure out?

A

Whether genes were made of protein or DNA. by using bacteriophages

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

What did Hershey and Chase conclude?

A

the genetic material of the bacteriophage was DNA, not protein

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

What are nucleotides?

A

units that make up DNA

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

What are genes known to do?

A

1) carry info from 1 gen. to the next
2) put info to work by determining the heritable characteristics of organisms
3) had to be easily copied

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

What is a nucleotide made of?

A

a 5-carbon sugar (deoxyribose), a phosphate group, and a nitrogenous (nitrogen-containing) base

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

What are the nitrogenous bases of DNA?

A

Adenine, Guanine, Cytosine and Thymine

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

Who was Erwin Chargaff?

A

an American biochemist that discovered that the percentages of guanine and cytosine bases are almost equal and the percentages of adenine and thymine bases are almost equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Who was Rosalind Franklin?

A

She used X-ray diffraction to get info about the structure of DNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What did photo 51 show?

A

Photo 51 showed that the strands of DNA are twisted around each other like coils of spring (helix). The angle of the X suggests that there are 2 strands in the structure. It also suggests that the nitrogenous bases are near the center of the molecule.

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

Who were Watson and Crick?

A

Made a 3D model of DNA based on Franklin’s Photo 51

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

What is the structure of DNA called? What does it look like?

A

Double helix; twisted ladder/spiral staircase

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

What is base pairing? What does it state?

A

Explained Chargaff’s rules; for every adenine molecule, there had to be exactly one thymine molecule. And for each cytosine molecule, there had to be exactly one guanine molecule.

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

Eukaryotic chromosomes contain both DNA and protein, tightly packed together to form a substance called what?

A

chromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are histones?

A

proteins that DNA is wrapped around

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

What is a nucleosome?

A

beadlike structures of DNA and histone molecules

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

What do nucleosomes do?

A

fold enormous lengths of DNA into the tiny space available in the cell nucleus

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

What are replication forks?

A

sites where separation and replication occur

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

What happens in DNA replication?

A

The DNA molecule separates into 2 strands, and then produces 2 new complementary stands following the rules of base pairing. Each strand of the double helix of DNA serves as a template or model for the new strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is DNA polymerase?

A

The principal enzyme involved in DNA replication

26
Q

What does DNA polymerase do?

A

Joins individual nucleotides to produce a DNA molecule; it proofreads each new DNA strand helping to maximize the odds that each molecule is a perfect copy of the original

27
Q

What are the differences of DNA and RNA?

A

1) the sugar in RNA is ribose while DNA has deoxyribose
2) RNA is generally single-stranded
3) RNA contains uracil in place of thymine
4) RNA is a disposable copy of a segment of DNA
5) DNA is the blueprint

28
Q

What are messenger RNA (mRNA) ?

A

RNA molecules that carry copies of protein-making instructions from the DNA to the rest of the cell

29
Q

What is ribosomal RNA (rRNA) ?

A

RNA found in ribosomes

30
Q

What is transfer RNA (tRNA) ?

A

transfers each amino acid to the ribosome as it is specified by coded messages in mRNA

31
Q

What enzyme does transcription require?

A

RNA polymerase

32
Q

What happens during transcription?

A

RNA polymerase binds to DNA and separates the DNA strands. RNA polymerase then uses one strand of DNA as a template from which nucleotides are assembled into a strand of RNA

33
Q

What are promoters?

A

Regions of DNA where RNA polymerase binds to

34
Q

What are introns?

A

Sequences of nucleotides that are not involved in coding for proteins

35
Q

What are exons?

A

the DNA sequences that code for proteins; they are “expressed” in protein synthesis

36
Q

What is RNA editing?

A

RNA molecules edit out the introns out of them before they become functional; exons are spliced together; then a cap and tail are added to form the final RNA molecule

37
Q

What is a codon?

A

consists of 3 consecutive nucleotides that specify a single amino acid that is to be added to the polypeptide

38
Q

How many possible codons are there?

A

64 ; some amino acids can be specified by more than one codon

39
Q

What is translation?

A

the decoding of an mRNA message into a polypeptide chain

40
Q

Where does translation take place?

A

ribosome

41
Q

What happens during translation?

A

the cell uses information from mRNA to produce proteins

42
Q

What does tRNA have?

A

anticodons

43
Q

What does tRNA do in translation?

A

It brings the amino acid of the specified codon on mRNA as it attaches its anticodon to mRNA

44
Q

What are mutations?

A

changes in the genetic material

45
Q

What are the 2 types of mutations?

A

Gene and chromosomal

46
Q

What are gene mutations?

A

Mutations that produce changes in a single gene

47
Q

What are chromosomal mutations?

A

Mutations that produce changes in whole chromosomes

48
Q

What are point mutations?

A

A type of gene mutation that involve changes in one or a few nucleotides

49
Q

What are frameshift mutations?

A

A type of gene mutation that shift the reading frame of the genetic message (insertion or deletion)

50
Q

What are the 4 types of chromosomal mutations?

A

deletions, duplications, inversions, and translocations

51
Q

What happens in deletion?

A

loss of all or part of a chromosome

52
Q

What happens in duplications?

A

extra copies of parts of a chromosome are made

53
Q

What happens in inversions?

A

the direction of parts of chromosomes are reversed

54
Q

What happens in translocations?

A

part of one chromosome breaks off and attaches to another

55
Q

What is polyploidy?

A

an organism has extra sets of chromosomes (3N or 4N)

56
Q

What is lac operon?

A

a group of genes that must be expressed in order for the bacterium (E. Coli) to be able to use the sugar lactose as food

57
Q

What is an operator?

A

region where the lac repressor attaches to

58
Q

How is the lac operon regulated?

A

A repressor is attached to the operator. RNA polymerase attaches to the promoter. When lactose is present, a lactose molecule attached to the repressor and changes its shape, making it “fall off” the operator. Once the operator is free, RNA polymerase transcribes the lac operon. When lactose is gone, a repressor attaches itself back to the operator and the lac operon is turned off.

59
Q

How are most eukaryotic genes controlled?

A

individually with regulatory sequences that are much more complex that those of the lac operon

60
Q

Why is gene regulation in eukarytoes more complex than in prokaryotes?

A

Cell specialization requires genetic specialization but all of the cells in a multicellular organism carry the complete genetic code in their nucleus. Therefore, for proper overall function, only a tiny fraction of the available genes needs to be expressed in the appropriate cells of different tissues. Gene regulation makes this specificity possible

61
Q

Hox genes control what?

A

Cell specialization

Biology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions