3.4.1 DNA, Genes and Chromosomes Flashcards

1
Q

Describe DNA molecules in prokaryotic cells?

A

Short
Circular
Not associated with proteins

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

How does protein synthesis differ in prokaryotic and eukaryotic cells?

A

Transcription occurs in the nucleus in a eukaryotes; transcription occurs in the cytoplasm of a prokaryote
Translation occurs in the cytoplasm of eukaryotes and prokaryotes

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

Where is DNA found in prokaryotic cells?

A

Loose in the cytoplasm

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

Where is DNA found in eukaryotic cells?

A

In a membrane bound nucleus

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

In what form is the DNA in a prokaryotic and eukaryotic cell?

A

Prokaryotic- a single loop (with plasmids)

Eukaryotic- linear chromosomes

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

Is the DNA is prokaryotic and eukaryotic cells associated with proteins?

A

Prokaryotic- no (not a chromosome)

Eukaryotic- yes, wrapped around histones

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

What is the length of the DNA molecules in a prokaryote and eukaryotes?

A

Prokaryote- shorter

Eukaryote- longer

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

Where is DNA found in eukaryotic cells?

A

Nucleus
Mitochondria
Chloroplasts

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

How is DNA thought to have got into mitochondria and chloroplasts?

A

Endosymbiotic theory

Mitochondria and chloroplasts were once free living prokaryotes that were engulfed by a cell

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

Define chromosome.

A

Thread like structure found in the nucleus of eukaryotic cells
Consists of a single molecule of DNA
Highly wound around protein molecules called chromatin

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

What is a gene?

A

A section of DNA that codes for the amino acid sequence of one polypeptide

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

What is a locus?

A

The position on a particular chromosome where you find a gene

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

What is a homologous pair?

A

Chromosome pairs
One from each parent
Similar in length, gene position and centromere location

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

How many pairs of chromosomes does a human have?

A

23

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

What is an allele?

A

The different forms a gene can take

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

Define diploid.

A

A cell that contains two sets of chromosomes

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

What is a diploid number?

A

The number of chromosomes in a cell

Abbreviated to 2n (where n is the number of chromosomes)

18
Q

Define homozygous.

A

Where both alleles for a gene are the same

19
Q

Define heterozygous.

A

Where the alleles for a gene are different

20
Q

What does it mean if a cell is haploid?

A

Contains one complete set of chromosomes

21
Q

Give an example of a haploid cell?

22
Q

When are haploid cells produced?

23
Q

What is the haploid number?

A

Number of chromosomes within the cell that is the set

24
Q

Define genome.

A

The full set of genes in a cell

25
Define proteome.
The full range of proteins coded for by the genes
26
Define karyotype.
The number and appearance of chromosomes in the nucleus of a eukaryotic cell
27
Why isn’t DNA stored in the nucleus of a prokaryotic cell?
They have no nucleus!
28
What is the purpose for the cooling of DNA in a chromosome?
So it is easy to separate/ unravel DNA without damaging it | For DNA replication
29
Describe the structure of a chromosome.
A DNA double helix strand forms a chromatin fibre This wraps around histone proteins Histone proteins coil to make a chromatin fibre These form loops Loops form rosettes These coil together One chromatid is 10 coils long
30
Define exon.
Sequences of bases in a gene that code for a sequence of a amino acids in a protein
31
Define intron.
Non-coding DNA which can be found between genes in multiple repeats or within genes
32
Why is DNA a ‘universal code’?
DNA is used in virtually all organisms as the material of inheritance
33
What is a codon?
The sequence of three bases that codes for one amino acid
34
What is degenerate code?
Amino acids are coded for by more than 1 codon
35
What makes DNA ‘non-overlapping’?
Each base in the sequence is read only once so the code is non-overlapping
36
Why are three bases needed to core for each amino acid?
There are 4 bases If one base coded for one amino acid there would only be 4 possibilities If they were in pairs there would only be 16 possibilities We need 20 different codes With 3 bases there are 64 possible combinations
37
What is an advantage to a cell of having degenerate code?
If there is a substitution mutation in the third base of a codon, the impact will be small on the amino acid made (eg GGA and GGG codes for the same thing)
38
Which bases are involved in the triplet code table?
ATGC
39
Ow many amino acids would be coded for from AAACACTTGGTC?
4
40
What do polypeptides combine to produce?
Proteins