DNA packing Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

how big is the nucleus of a cell

A

a human cell nucleus is 5-8um in diameter and has 2m of DNA

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

What is the human genome

A

DNA sequence needed to make a human and is split into 23 pairs of chromosomes

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

what 2 things can cells be

A

haploid or diploid

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

what is haploid

A

only one copy of each chromosome (23 germ cells)

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

what is diploid

A

2 copies of each chromosome (46 chromosomes- all other cells)

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

how many pairs of chromosomes are there

A

22 pairs + 1 pair of identical sex chromosomes

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

what are the sex chromsomes

A

they give gender- males = XY females = XX

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

What is Down’s syndrome

A

3 copies of 21 chromosome

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

what is a karyotype

A

image of human chromosome set

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

what is normal cell division

A

mitosis and occurs in the M phase

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

what 3 DNA sequences are needed in a chromosome

A

telomere, replication origin and centromere

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

what are nucleosomes

A

DNA is packed into a cell by winding it around special stool structures (each nucleosome has 8 histone proteins)

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

what are histone proteins

A

what nucleosomes are built out of

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

what are scaffold proteins

A

where coils of nucleosomes are attached to a protein framework

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

what are protein filaments

A

inside and outside and they support the nucleus

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

can the M Phase be viewed

A

DNA is tightly packed and individual chromosomes are easily seen

17
Q

can the interphase be seen

A

loosely packed DNA can be seen on lysing nuclei

18
Q

what is the nucleolus

A

where ribosomes are produced. rRNA associate with each other here and ribosomes export through pores

19
Q

what makes up DNA

A

DNA is made up of chemical units symbolised by a single letter and since DNA is a continuous strand it Is a string of letters

20
Q

what is a start codon e.g

A

Catt

21
Q

what is a stop codon e.g

A

tcac

22
Q

what is a gene

A

a stretch of DNA that codes for one protein or RNA and produces a given polypeptide

23
Q

what signals the start or stop of a gene

A

a certain sequence of nucleotides