3.1 + 3.2 genes and chromosomes Flashcards

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

what is a gene?

A

a heritable factor that consists of a length of DNA and influences a specific characteristic

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

what are alleles?

A

the various specific forms of genes

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

how are new alleles formed?

A

by mutation

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

new alleles form as a result of mutations, contributing to increased…

A

genetic variation

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

sickle cell anaemia is caused by ___________ mutation

A

base substituition

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

why is haemoglobin different in an individual with sickle cell anaemia?

A
  • due to base substitution mutation in gene coding for haemoglobin protein
  • which leads to a change in the base sequence of mRNA transcribed
  • this leads to a change in the sequence of polypeptide in haemoglobin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

sickle cell anaemia is an [autosomal/sex-linked] disorder

A

autosomal

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

what is the difference in RBC in a healthy individual and an individual w sickle cell anaemia?

A

healthy: biconcave shape
sickle cell anaemia: sickle shaped

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

what are the implications of individuals w sickle cell anaemia?

A

sickle cells may clump together and clog blood vessels, interfering w blood circulation

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

sickle cell anaemia is [recessive/dominant]

A

recessive

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

what are 2 symptoms of sickle cell anaemia?

A

chronic anaemia and jaundice

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

what is a genome?

A

it refers to all the DNA present in an individual

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

what is the human genome project for?

A
  • to work out the base sequences of the human genome
  • and identify the location of these genes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are some outcomes of the human genome project?

A
  • mutations can be located and genes associated with diseases can be identified
  • tests for genetic diseases can be developed → earlier detection
  • evolutionary history can be studied
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

prokaryotes have circular DNA while eukaryotes have _______ DNA

A

linear

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

what is the opposite of naked DNA?

A

DNA associated w histones

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

___karyotes have homologous chromosomes

A

eukaryotes

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

eukaryotes have… but prokaryotes don’t have these

A

centromeres, telomeres, homologous chromosomes

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

what enables transcription and translation to occur simulataneously in prokaryotes?

A

DNA is not membrane bound

20
Q

plasmids confer ________ traits

A

advantageous

21
Q

what are nucleosomes made out of?

A

DNA wrapped twice around octamers (8 of them) of histones

22
Q

what method was involved in Cairn’s technique?

A

autoradiography

23
Q

what is Cairn’s technique used for?

A

to measure the length of DNA molecules

24
Q

what organism did Cairn use?

A

E coli

25
Q

what did Cairn label as radioactive? and why?

A
  • thymine using isotope of hydrogen
  • radioactive thymine would be incorporated into new DNA strands
  • radiation released by labelled thymine can be seen using autoradiography
26
Q

how was the DNA released from the bacteria?

A

the bacteria was lysed using enzymes, releasing DNA

27
Q

how is radioactivity seen on photographic film?

A

radioactivity darkens the film

28
Q

how does newly synthesised DNA look like on the film?

A

line of black dots

29
Q

autoradiography involves these materials:

A
  1. photographic film
  2. photographic emulsion
30
Q

what did Cairn’s technique show?

A

E coli DNA was much longer than the E coli cells

31
Q

how many chromosomes do Homo sapiens have?

A

46

32
Q

how many chromosomes do Pan troglodytes have?

A

48

33
Q

which organism has 48 chromosomes?

A

Pan troglodytes

34
Q

how many chromosomes does Canis familiaris have?

A

78

35
Q

how many chromosomes does Oryza sativa have?

A

24

36
Q

Parascaris equorum has ____ chromosomes

A

2

37
Q

which organism has 78 chromosomes?

A

Canis familiaris

38
Q

Homo sapiens have ____ base pairs

A

3.2 bil

39
Q

how many base pairs does a T2 phage have?

A

170k

40
Q

how many base pairs does a Escherichia coli have?

A

4.6 mil

41
Q

which organism has 130 mil base pairs

A

Drosophilia melongaster

42
Q

__________ has the longest genome length

A

Paris japonica

43
Q

Paris japonica has _____ base pairs

A

150 bil

44
Q

Drosophilia melongaster has _____ base pairs

A

130 mil

45
Q

what do karyograms show?

A

an organism’s homologous chromosomes in decreasing length