Brainscape's Knowledge GenomeTM

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


See full index

MOLGEN > CH 1 book terms > Flashcards

CH 1 book terms Flashcards

1
Q

alleles

A

One of several alternative forms of a gene occupying a given
locus on a chromosome.

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

annealing/hybridization

A

The renaturation of a duplex structure from single strands that were obtained by denaturing duplex DNA.

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

antiparallel

A

two polynucleotide chains running in opposite directions

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

antisense/template strand

A

the sequence of mRNA is complementary to the sequence of one strand of DNA

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

back mutations

A

A mutation that reverses the effect of a mutation that had inactivated a gene; thus, it restores the original sequence or function of the gene product.

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

base pairing

A

hydrogen bonding between bases

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

bivalent

A

The structure containing all four chromatids (two representing each homologue) at the start of meiosis.

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

causes of point mutations

A
  1. Chemical modification of DNA directly changes one base into a different base.
  2. An error during the replication of DNA causes the wrong base to be inserted into a polynucleotide.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

central dogma

A

DNA to RNA to polypeptide

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

chiasma

A

The point of synapsis between homologs

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

chromatid

A

Either of the two threadlike strands formed when a
chromosome duplicates during the early stages of cell division. The two strands are held together at the centromere and separate into daughter chromosomes during anaphase.

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

chromosome

A

A discrete unit of the genome carrying many genes. Each
consists of a very long molecule of duplex DNA and an
approximately equal mass of proteins (in eukaryotes).

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

cis-acting

A

A site that affects the activity only of sequences on its own molecule of DNA (or RNA); this property usually implies that the site does not code for protein.

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

coding/sense strand

A

the sequence of mRNA is identical (apart from the replacement of T with U) to the other strand of DNA

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

codon

A

Each trinucleotide sequence

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

colinear

A

The relationship that describes the 1:1 correspondence of a sequence of triplet nucleotides to a sequence of amino acids.

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

denaturation

A

A molecule’s conversion from the physiological conformation to some other (inactive) conformation. In DNA, this involves the separation of the two strands due to breaking of hydrogen bonds between bases.

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

DNA polymerases

A

An enzyme that synthesizes a daughter strand(s) of DNA (under direction from a DNA template). Any particular enzyme may be involved in repair or replication (or both).

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

DNases

A

degrade DNA

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

endonucleases

A

break individual phosphodiester linkages within RNA or DNA molecules, generating discrete fragments

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

exons

A

The sequences that are transcribed, retained, and joined in the mature mRNA

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

exonucleases

A

remove nucleotide residues one at a time from the end of the molecule, generating mononucleotides

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

forward mutations

A

A mutation that inactivates a functional gene

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

frameshift mutation

A

A genetic mutation formed through the addition or deletion of nucleotide bases such that the reading frame is thrown off. The resulting polypeptide formed is usually abnormally short or abnormally long and most likely nonfunctional.

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

gain-of-function mutations

A

A mutation that causes an increase in the normal gene activity. It sometimes represents acquisition of certain abnormal properties. It is often, but not always, dominant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

gene expression

A

The process by which information from a gene is used to synthesize an RNA or polypeptide product

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

genetic code

A

The relationship between a sequence of DNA and the sequence of the corresponding polypeptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

genetic recombination

A

the generation of new combinations of alleles at each generation in diploid organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

genome

A

a long sequence of deoxyribonucleic acid (DNA) that provides the complete set of hereditary information carried by the organism as well as its individual cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

heteroduplex DNA

A

DNA that is generated by base pairing between complementary single strands derived from the different parental duplex
molecules; it occurs during genetic recombination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

heteromultimer

A

A protein composed of two or more different polypeptide chains.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

homomultimer

A

A molecular complex (such as a protein) in which the subunits are identical.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

hotspots

A

A site in the genome at which the frequency of mutation (or
recombination) is very much increased, usually by at least an order of magnitude relative to neighboring sites.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

induced mutations

A

Mutations that result from the action of a mutagen. The mutagen may act directly on the bases in DNA or it may act indirectly to trigger a pathway that leads to a change in DNA sequence.

35
Q

introns

A

these internal DNA sequences are initially transcribed but are excised and are not present in the mature mRNA

36
Q

leaky mutations

A

A less severe type of mutation where the amino acid substitution does not completely deactivate a certain function of
the protein, but rather decreases its function or makes it less effective.

37
Q

linkage

A

The tendency of genes to be inherited together as a result of their location on the same chromosome; measured by percent recombination between loci.

38
Q

linking number

A

In a closed molecule of DNA, the number of times one strand crosses over another in space.

39
Q

locus

A

The position on a chromosome at which the gene for a particular trait resides; it may be occupied by any one of the alleles for the gene

40
Q

loss-of-function mutation

A

A mutation that eliminates or reduces the activity of a gene. It is often, but not always, recessive.

41
Q

major groove

A

A fissure running the length of the DNA double helix that is 22 Å across.

42
Q

melting temperature

A

The midpoint of the temperature range over which the strands of DNA separate

43
Q

messenger RNA

A

a nucleic acid intermediate actually used to synthesize a polypeptide

44
Q

minor groove

A

A fissure running the length of the DNA double helix that is 12 Å across.

45
Q

multiple alleles

A

A non-Mendelian pattern of inheritance where more than two alleles code for a trait. In most cases, the result is that more than two phenotypes are possible based on the dominance pattern of the individual alleles.

46
Q

mutagens

A

Substances that increase the rate of mutation by inducing changes in DNA sequence, directly or indirectly.

47
Q

nucleoside

A

pentose sugar linked to a nitrogenous base

48
Q

nucleotide

A

A nucleoside linked to a phosphate at the 5′
carbon

49
Q

null mutation

A

A mutation that completely eliminates the function of a gene.

50
Q

overwound

A

DNA has more base pairs per turn

51
Q

point mutation

A

changes only a single base pair

52
Q

polymorphism

A

The simultaneous occurrence in the population of alleles
showing variations at a given position.

53
Q

polynucleotide

A

a long chain of nucleotides

54
Q

positive vs negative supercoiling

A

Twisting in the same direction produces positive supercoiling, which overwinds the DNA so that there are fewer base pairs per turn.
Twisting in the opposite direction produces negative supercoiling, or underwinding, so there are more base pairs per turn.

55
Q

prion

A

proteinaceous infectious agent

56
Q

purine

A

A double-ringed nitrogenous base, such as adenine or guanine.

57
Q

pyrimidine

A

A single-ringed nitrogenous base, such as cytosine, thymine, or uracil.

58
Q

renaturation

A

The reassociation of denatured complementary single strands of a DNA double helix.

59
Q

replication fork

A

The point at which strands of parental duplex DNA are separated so that replication can proceed.

60
Q

reverse transcription

A

RNA is converted into a single-stranded DNA

61
Q

revertants

A

Reversions of a mutant cell or organism to the wild-type phenotype.

62
Q

ribosome

A

A large assembly of RNA and proteins that synthesizes proteins under direction from an mRNA template.

63
Q

RNA polymerase

A

An enzyme that synthesizes RNA using a DNA template.

64
Q

RNases

A

degrade RNA

65
Q

roles of proteins

A

they can form part of the structure of the organism; have the capacity to build the structure; perform the metabolic reactions necessary for life; and participate in regulation as transcription factors, receptors, key players in signal transduction pathways, and other molecules

66
Q

second-site reversion

A

A second mutation suppressing the effect of a first mutation.

67
Q

semiconservative replication

A

DNA replication accomplished by separation of the strands of a parental duplex, each strand then acting as a template for synthesis of a complementary strand.

68
Q

silent mutations

A

A mutation that does not change the sequence of a polypeptide because it produces synonymous codons.

69
Q

splicing

A

The process of excising introns from RNA and connecting the exons into a continuous mRNA.

70
Q

spontaneous mutations

A

Mutations occurring in the absence of any added reagent to increase the mutation rate, as the result of errors in replication (or other events involved in the reproduction of DNA) or by random changes to the chemical structure of bases.

71
Q

structural genes

A

A gene that codes for any RNA or polypeptide product other than a regulator.

72
Q

supercoiling

A

the double helix can also wind around itself to change the overall conformation, or topology, of the DNA molecule in space

73
Q

suppression mutation

A

A second event eliminates the effects of a mutation without reversing the original change in DNA.

74
Q

tetrad

A

A four-part structure that forms during the prophase of meiosis. Consists of two homologous chromosomes, each composed of two sister chromatids.

75
Q

topological isomers

A

Molecules with the same chemical formula but different bond connectivities, thus resulting in different topologic structures.

76
Q

trans-acting

A

A product that can function on any copy of its target DNA. This implies that it is a diffusible protein or RNA.

77
Q

transcription

A

when a RNA copy of the coding strand of the DNA is produced

78
Q

transition

A

the substitution of one pyrimidine by the other, or of one purine by the other

79
Q

translation

A

Synthesis of Protein on an mRNA template
mRNA to protein

80
Q

transversion

A

a purine is replaced by a pyrimidine, or vice versa

81
Q

true reversion

A

A mutation that restores the original sequence of the DNA.

82
Q

twisting number

A

In the DNA double helix, the rotation of one strand about the other.

83
Q

types of point mutations

A

transition and transversion

84
Q

underwound

A

fewer base pairs per turn

MOLGEN (28 decks)

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