Brainscape's Knowledge GenomeTM

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


See full index

Year Three - Specialities > Genetics - Basic Information > Flashcards

Genetics - Basic Information Flashcards

1
Q

What is DNA?

A

It consists of two strands of nucleotide monomers that wrap around one another to form a double helix

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

What is a nucleotide monomer made up of?

A

A sugar

A base

A phosphate group

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

What are the four DNA bases?

A

Adenine

Cytosine

Guanine

Thymine

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

What is found in the centre of the DNA double helix?

A

Bases

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

What makes up the backbone of the DNA double helix?

A

Sugars

Phosphates

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

What directions do the polynucleotide chains run in relation to each other?

A

They run anti-parallel to one another, as one runs 5’ to 3’ and the other runs from 3’ to 5’

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

What are the two DNA grooves?

A

Major groove

Minor groove

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

What is the major DNA groove?

A

It occurs where the backbones are far apart

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

What is the minor DNA groove?

A

It occurs when the backbones are close together

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

How are the two polynucleotide chains linked together?

A

Complementary base-pairing

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

What are the two DNA base pairings?

A

Adenine - Thymine

Cytosine - Guanine

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

What bonds bind DNA bases together?

A

Hydrogen bonds

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

Where is DNA located in cells?

A

Nucleus

Ribsosomes - they contain their own DNA

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

How is DNA stored in the nucleus?

A

Chromsomes

Chromatins

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

What structure is found in the centres of the nucleus?

A

Nucleolus

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

What structure is located around the nucleus?

A

Nuclear envelope

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

What is the function of the nuclear envelope?

A

It consists of nuclear pores, which allows the passage of molecules into and out of the nucleus

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

What are chromosomes?

A

A single piece of DNA containing many genes, regulatory elements and other nucleotide sequences

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

What structure divides chromosomes into two sections?

A

Centromere

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

What are the two sections of a chromosome? Which section is smaller and which is larger?

A

P - smaller

Q - larger

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

What structure is contained within the centromere?

A

Kinetochore

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

What is kinetochore?

A

A protein complex that binds to microtubules

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

What is the function of kinetochore?

A

It is involved in cell division

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

Describe the process in which DNA is packaged into chromosomes

A

DNA is wrapped around histone proteins to form structures known as nucleosomes

These nucleosomes then fold up to form a chromatin fibre

These fibres then wrap around one another to form a chromosome

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

Why is DNA wrapped around histone proteins?

A

DNA is negatively charged

Histone proteins are positively charged

This neutralises the negatively charged DNA, which means that DNA takes up less space and inactive DNA can be folded into inaccessible locations

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

What are the two types of chromatin?

A

Heterochromatin

Euchromatin

27
Q

What is heterochromatin?

A

It is highly condensed form of chromatin that contains silenced genes

28
Q

What is euchromatin?

A

It is an extended form of chromatin that contains active genes

29
Q

When are chromatins formed?

A

During the S phase of interphase

30
Q

What are telomeres?

A

They are the caps at the end of the DNA strands that protect our chromosomes

They they are repetitive sequences of DNA that code for no particular genes

31
Q

How do telomeres protect our chromosomes?

A

They prevent important genes from being deleted during cell division and DNA replication

32
Q

Describe the end problem of linear DNA replication

A

After DNA replication, each new DNA strand is shorter at its 5’ end than at the parental DNA’s strand’s 5’ end

This produces a 3’ overhang at one end of each daughter DNA strand

This means that some of our DNA on the 5’ strand is not replicated

This end problem explains why the telomeres are so important in DNA replication, as they are shortened from the DNA, but the important genes aren’t

33
Q

What is telomerase?

A

It is an enzyme that fills in the gaps as a result of the end problem of linear DNA replication

34
Q

Describe how telomerase corrects the end problem of linear DNA replication

A

It contains a catalytic part and a built-in RNA template.

It binds to the end of a chromosome to add complementary RNA bases to the 3’ end of the DNA strand

Once the 3’ end of the lagging strand template is sufficiently elongated, DNA polymerase adds the complementary nucleotides to the ends of the chromosomes, allowing the ends of the chromosomes to be replicated

35
Q

DNA is said to be semi-conservative. What does this mean?

A

This means that one half of each new molecule of DNA is old and the other half is new

36
Q

Describe the process of DNA replication

A

The hydrogen bonds hydrogen bonds between the complementary base-pairs are broken by special proteins

This allows the double helix to be unzipped

The new nucleotide molecules then pair with the bases on the two DNA strands

These nucleotides molecules are joined together through the enzyme DNA polymerase.

This enzyme can only add new nucleotides to the 3’ end of the growing strand, as DNA is replicated in the 5’ to 3’ direction

On the lagging strand, DNA polymerase joins the nucleotides into fragments, not a whole strand

This means that this strand requires an additional enzyme, known as ligase, to come and join the fragments together to form one continuous strand

37
Q

What are exons?

A

They are the coding regions of DNA

38
Q

What is the function of exons?

A

They exit the nucleus in the form of mRNA to be coded into proteins at the ribosome

39
Q

What are introns?

A

They are the non-coding regions of DNA

40
Q

What are introns?

A

They are the non-coding regions of DNA

41
Q

What is the function of introns?

A

They stay inside the nucleus as they don’t need to be coded into proteins at the ribosome

42
Q

What is a codon?

A

A set of three bases

43
Q

What does each codon code for?

A

One amino acid

OR

STOP/START code

44
Q

What is degeneracy of the genetic code?

A

This means that amino acids can be coded by more than one codon

45
Q

Which two amino acids are not degenerate?

A

Methionine

Tryptophan

46
Q

What term is used to refer to codons which refer to the same amino acid?

A

Synonyms

47
Q

Where do variations between synonyms occur? What is this called?

A

Third base of the codon

Wobble position

48
Q

Why is degeneracy of the genetic code important?

A

This minimises the effect of genetic mutations, as alterations to the base sequences are less likely to alter the protein being coded for

49
Q

What amino acid is termed as the START codon?

A

Methionine

50
Q

What is the function of the START codon?

A

This this is the signal for protein synthesis to begin

51
Q

Why do not all polypeptides begin with methionine?

A

It can be removed at a later stage

52
Q

What are the three types of RNA?

A

mRNA (messenger RNA)

tRNA (transfer RNA)

rRNA (ribosomal RNA)

53
Q

What is the function of mRNA?

A

It is involved in transporting the genetic code from the nucleus to the ribosome so that protein synthesis can occur

54
Q

What is mRNA transcribed from?

A

DNA

55
Q

What is the function of tRNA?

A

It is involved in linking codons to their specific amino acid at the ribosome

56
Q

What does tRNA consist of?

A

Anticodons

57
Q

What is the function of anticodons?

A

They are able to pair to the codons on the mRNA chain

When this pairing occurs, the amino acid held by the tRNA molecule is joined onto the growing chain of amino acids

58
Q

What is rRNA?

A

A component of ribosomes

59
Q

Where is rRNA produced?

A

Nucleus

60
Q

Where is rRNA transported to?

A

Cytoplasm

61
Q

What does rRNA combine with to form a ribosome?

A

Proteins

62
Q

What is alternative splicing?

A

It is a process by which the exons of the RNA are reconnected in multiple ways during RNA splicing

The resulting different mRNAs may be translated into different protein isoforms; thus, a single gene may code for multiple proteins

63
Q

What is the number of chromosomes, autosome pairs and sex chromosome pars in a normal human cell?

A

Chromosomes - 46

Autosome pairs - 22

Sex chromosome pairs - 1

Year Three - Specialities (15 decks)

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