Brainscape's Knowledge GenomeTM

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


See full index

Grade 12 Biology > Molecular Genetics - Till Midunit > Flashcards

Molecular Genetics - Till Midunit Flashcards

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

What are the instructions in an organism’s DNA do

A

Provide the direction to build the proteins the organism requires

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

What is DNA responsible for ensuring

A

genetic continuity

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

What is specific about chromosomes when it comes to different species

A

Size and number of chromosomes

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

What is the name of the plant with the most chromosomes

A

The Adder’s Tongue Fern

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

What are the three steps that need to occur to go from a gene (DNA) to a polypeptide

A

Portion of DNA that codes for a protein is activated, the nucleotide sequence is transcribed into a molecule of RNA which then moves to the cytosol where its sequence is translated by ribosomes into polypeptides

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

Where is DNA stored in Eukaryotes

A

The nucleus

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

Where is DNA stored in prokaryotes

A

The nucleoid region

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

What are genes

A

Genes are the coding regions of DNA which contain the instructions to build proteins responsible for each trait

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

What are alleles

A

Versions of each gene that give a trait more than 1 potential physical appearance

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

How do eukaryotes pack all of their DNA into a cell

A

A DNA strand is wrapped around 8 alkaline histone proteins and they are held together by positive and negative charges. It coils up to protect itself and fit

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

What is a genome

A

A genome is the complete set of an organisms hereditary material

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

What is the size of a human genome

A

3 billion base pairs

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

How many genes do humans have

A

20-25000

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

What functional group is associated with the 3’ Carbon

A

Hydroxyl group

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

What functional group is associated with the 5’ Carbon

A

Phosphate group

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

What is the orientation that the strands of DNA run in

A

Anti parallel

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

What is the distance between each base pair

A

0.34 nanometers

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

What way does the double helix turn

A

Clockwise

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

What is the size of one complete turn of the double helix of DNA

A

3.4 nanometers (10 base pairs)

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

What are the complimentary base pairs

A

Adenine - Thymine
Guanine - Cytosine

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

How many hydrogen bonds does the G-C base pair create

A

3 Hydrogen Bonds

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

How many hydrogen bonds does the A-T base pair create

A

2 Hydrogen Bonds

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

What is the bond that connects the sugar and base in a nucleotide

A

Glycosyl Bond

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

When a lot of crossing over occurs, what happens to the distance between two genes

A

They get farther apart

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

What did Gregor Mendel do

A

Carried out genetic experiments with pea plants and then published his work on the principles of genetics (called them factors at the time)

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

What did Fredrich Miescher do

A

Isolated a substance from the nucleus of white blood cells which he called nuclein (now known as DNA)

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

What did Sutton and Boveri do

A

Proposed the chromosome theory of heredity. They both independently realized that the factors mendel talked about were on the chromosomes

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

What did Thomas Morgan Hunt do

A

Morgan was skeptic of the Sutton Boveri theory, however he then identified the first X-Linked gene in fruit flies showing that a trait could be linked to the sex of the fly supporting Sutton and Boveri’s theory

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

After proving sex-linked traits, what did Morgan do

A

Described Gene linkage where genes on the same chromosomes are linked together

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

What did Alfred Sturtevant do

A

He was a student in Morgan’s lab who created the first gene map

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

What does crossing over do

A

Brings new phenotypes

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

What is an example of gene linkage

A

Blue eyes and blonde hair on the same chromosome

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

What did Griffith discover in his mouse disease experiment

A

Dead cells’ pathogenic properties could be passed on to living bacterial cells, this was the accidental “Transforming Principle”

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

As Griffith passed away in an air raid during WWII, who carried on with his work

A

Avery and his team were the first to demonstrate that the transforming principle was likely DNA, This experiment was not conclusive as it was a negative experiment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Who provided conclusive evidence to say that DNA was the genetic material

A

Hershey and Chase did a radioactive DNA experiment where they took radioactive DNA and Radioactive Protein and added them to samples of E-Coli, this was conclusive that DNA was the genetic material INSTEAD of protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Why was Avery and his team hesitant to report their findings

A

At the time it was believed that protein were the genetic material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What did Joachim Hammerling prove

A

Used Green alga (Acetabularia) and determined that its genetic information was store in the nucleus containing foot which meant that the nucleus contained the hereditary material. He did this by cutting the alga to the foot, and saw that it regenerated a copy of the stalk and cap to its original state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What did Chargaff propose

A

Chargaff’s Rules stated that A=T and C=G, and that the complimentary pairs occured in the same ratios,
Adenine = x% and Thymine = x%, Guanine = y% and Cytosine = y%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What did Franklin and Wilkins do

A

Used X-Ray crystollography to show the shape of DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What was Franklin’s main acompolishment

A

Photo 51 which shows the x-ray diffraction pattern of a DNA molecule which provides info about the position of atoms in DNA (Equal spaces between rings)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What conclusion did Watson and Crick reach after seeing this image and reading Franklin’s report unethically

A

It was a double helix that had two antiparallel backbones on the outside with bases inside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What was Linus Pauling in the hunt for DNA exploration

A

He was a well known nobel prize winner in the states who was giving competition to those overseas, however his proposal of a triple helix was wrong

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What was unethical about Maurice Wilkins

A

Showed watson and crick photo 51 without telling franklin

44
Q

What were the three proposed mechanisms of DNA replication

A

Conservative replication (lots of bonds breaking and forming), Semi conservative (what actually happens), and Dispersive replication (regions of DNA interspersed with new DNA)

45
Q

After mitosis, 2 daughter cells end up with the same sets of chromosomes what does this mean and when does it occur

A

Means that DNA must replicate, occurs in the S Phase of Interphase

46
Q

What did Meselson’s and Stahl’s experiment say

A

Nitrogen is found in DNA, they grew e coli bacteria in a heavy isotope and then switched to a light isotope then used the density gradient centrifugation, cesium chloride was used. This allowed them to use this technique to predict and then test the results of DNA replication that semi conservative was the actual method of replication

47
Q

What type of replication did Watson and Crick propose

A

Semi conservative

48
Q

What happens before DNA replication to start it up

A

when proteins bind to the origin of replication, only one ori in prokaryotes but many in eukaryotes

49
Q

What are the two reasons that eukaryotes have many origins of replication

A

The DNA cannot be completely unwound because it would be too big to fit in the cell, it would also take far too long to replicate the 3 billion base pairs of human genome (700 days)

50
Q

What happens in the first step of DNA replication

A

DNA helicase breaks the bonds between complementary base pairs making them linear, single stranded binding proteins bind to the linear pairs preventing reannealing, DNA gyrase then relieves the tension created by unwinding the strands and cutting them

51
Q

What is the second step of DNA replication and what happens

A

Elongation is when replication starts in 2 different directions from each origin, the replication fork is the area where enzymes that are replicating DNA are bound to ssDNA, there is a replication fork at each end of a replication bubble

52
Q

After the replication bubble is created, what happens

A

A RNA primer (10-60 base pairs) is put on by the enzyme primase because DNA polymerase III, the enzyme that synthesizes DNA 5’ to 3’ can only add nucleotides to a free 3’ end.

53
Q

Where does Energy for elongation come from

A

Deoxyribonucleoside triphosphates

54
Q

What is the leading strand

A

The top strand of DNA going from 5’ to 3’ built continuously toward the replication fork with only one RNA primer at the 3’ end

55
Q

What is the lagging strand

A

The bottom strand of DNA from 5’ to 3’, but on the opposite sides as the Leading strand, and this is built discontinuously away from the replication fork with multiple RNA primers

56
Q

What does DNA Polymerase I do

A

excises the RNA primers and replaces them with appropriate DNA strands

57
Q

What happens after the excising of the RNA primers

A

DNA ligase joins the okazaki fragments by phosphodiester bonds to get rid of the gaps

58
Q

Without proofreading, what is the chance for a DNA replication error

A

1 in 10 000 base pairs

59
Q

What does the proofreading

A

DNA polymerase I and III act as an exonuclease which removes nucleic acids to fix incorrect base pairing (excises)

60
Q

After proof reading, what is the chance for DNA replication error

A

1 in 1 billion base pairs

61
Q

Why is prokaryotic DNA found in the nucleoid region

A

There is no nucleus

62
Q

What is the shape of prokaryotic DNA

A

The ends of DNA bind to form closed circular DNA loops which fold on themselves becoming supercoiled DNA

63
Q

In addition to the super coiled DNA, what other DNA molecules exist in prokaryotes

A

There are often other circular DNA molecules found in prokaryotes called plasmids where antibiotic resistance genes can usually be found

64
Q

What are characteristics of plasmids

A

They can be copied and transmitted between cells which is why antibiotic resistance can spread in bacteria

65
Q

What do plasmids help humans with in today’s world

A

Genetic engineering/biotechnology

66
Q

Do Eukaryotes also have supercoiled DNA

A

they do have supercoiled DNA, but it is not that important compared to that of the prokaryotes

67
Q

What is the length of one human genome

A

1.8m (6 billion base pairs, 3 billion from each parent)

68
Q

What are the constituents of chromosomes

A

5% RNA, 35% DNA, and 60% Protein

69
Q

What does DNA wrap around

A

8 Alkaline histone proteins to create a nucleosome

70
Q

What is a nucleosome

A

The bead-like structural unit of chromosomes composed of acidic DNA (200 base pairs) with a negative charge that are wrapped twice around a cluster of 8 alkaline histone proteins with a positive charge, opposites attract

71
Q

What percentage of the human genome is non coding

A

around 95%

72
Q

How do you compare the genomes of different individuals?

A

By their non coding regions

73
Q

What are non coding regions filled with

A

Variable number tandem repeats which are sequences of base pairs that are repeated over and over again

74
Q

What about the VNTR’s varies between individuals

A

The length of the base pair sequences, and the position of the repeating segment in the genome

75
Q

Can VNTR’s also be found in genes

A

Some VNTR’s on occasion can be found in the genes (coding regions)

76
Q

What are the ends of chromosomes made of, and what name are the ends given

A

The ends of chromosomes are made of long sequences of non coding DNA known as telomeres

77
Q

What is the main role of telomeres

A

Critical to preventing cells from losing valuable genomic material during DNA replication

78
Q

What would happen if DNA Gyrase was not available during DNA replication

A

The strands would not be able to relieve the tension created by the Helicase untwisting and so this could destabilize the strand and may also prevent the binding of other enzymes

79
Q

Given histones, solenoids, nucleosomes and Chromosomes, arrange them from smallest to largest in terms of molecule size

A

Histones, Nucleosomes, Solenoids, and Chromosomes

80
Q

When the RNA primer is removed from both daughter strands’ 5’ end, what happens

A

There becomes no adjacent nucleotide chain with a free 3’ end that can be extended to fill the gap and so no enzyme works in the 3’ to 5’ direction. Not only are their gaps on the daughter strands, the corresponding parent segments end up breaking off because the complementary strands are left unpaired.

81
Q

With each replication, what happens to the daughter strands

A

Each daughter strand becomes shorter than its parent, each time DNA is lost, the loss i approximately 100 base pairs

82
Q

What is the hayflick limit

A

Also known as cellular senescence, this limit says that in humans, DNA can be passaged 50 times before it can’t replicate anymore

83
Q

How big is the sequence of Telomeres

A

6 Base sequence repeated thousands of times

84
Q

What is the erosion of telomers related to

A

Cell death

85
Q

What does telomerase do

A

Extends the length of telomeres

86
Q

What do cancer cells have a lot of

A

Telomerase allowing them to divide well beyond normal life span

87
Q

To provide anti aging, what should be done to telomerase levels

A

Increase telomerase levels making cells and whole organism last longer, also an increased chance for cancer

88
Q

To treat cancer, what should be done to telomerase levels

A

Decrease telomerase levels making cancer cells not live long, however it will make you age faster as it will effect all cells

89
Q

What steps should be taken to maintain telomere length and increase telomerase levels in the human body

A

Less stress, excercising, good diet, and sleep

90
Q

What does obesity cause

A

Shorter telomeres

91
Q

Where is telomerase found

A

Stem cells and certain white blood cells

92
Q

Can conclusions be made about telomere length and life span between different species

A

No direct conclusions can be made based on solely this factor

93
Q

Where can full length telomeres be found

A

In germ cells, as those cells give rise to gametes

94
Q

What does cell life depend on

A

Depends on rate of telomere erosion, not length of telomeres

95
Q

Can shortening telomeres treat cancer

A

No, the underlying issue of heightened telomerase levels still exists and so it will just extend the telomeres again

96
Q

what is the one gene one enzyme hypothesis

A

each gene is unique and codes for the synthesis of a single enzyme

97
Q

what is the one gene one polypeptide hypothesis

A

each gene is unique and codes for the synthesis of a single polypeptide; the restated version of the one gene–one enzyme hypothesis

98
Q

What is the central dogma

A

the fundamental principle of molecular genetics, which states that genetic information flows from DNA to RNA to proteins

99
Q

What are the two main processes in the central dogma

A

Transcription and Translation

100
Q

What is transcription

A

mechanism by which the information coded in nucleic acids of DNA is copied into the nucleic acids of RNA; something rewritten in the same language occurring in the nucleus

101
Q

what is translation

A

mechanism by which the information coded in the nucleic acids of RNA is copied into the amino acids of proteins occurring in the cytoplasm

102
Q

What are the three differences between RNA and DNA

A

DNA is double stranded while RNA is single, Adenine pairs with thymine in DNA and with Uracil in RNA, in DNA the sugar is deoxyribose and Ribose in RNA

103
Q

what are the characteristics of mRNA

A
  • varies in length, depending on the gene that has been copied
  • acts as the intermediary between DNA and the ribosomes
  • is translated into protein by ribosomes
  • is the RNA version of the gene encoded by DNA
104
Q

what are the characteristics of tRNA

A
  • functions as the delivery system of amino acids to ribosomes as
    they synthesize proteins
  • is very short, only 70 to 90 base pairs long
105
Q

What allows mRNA to leave the nucleus after transcription

A

The pores in the nuclear membrane

Grade 12 Biology (7 decks)

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