Brainscape's Knowledge GenomeTM

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


See full index

AQA A Level Biology > Genetics, Diversity, and Classification > Flashcards

Genetics, Diversity, and Classification Flashcards

1
Q

How is DNA store in Eukaryotic Cells?

A

Wound around histones into chromosomes

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

How is DNA stored in Prokaryotic Cells?

A

a circular chromosome that is supercoiled to fit in the cell

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

What is a Gene?

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

What is a Locus?

A

the fixed position where each gene can be found on a chromosome

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

What is non-coding DNA?

A

DNA that does not code for polypeptides called introns

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

Where are introns found?

A

Between exons in Eukaryotic DNA

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

What are Alleles?

A

different forms of the same gene

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

What are Homologous Chromosomes?

A

a pair of chromosomes that are the same size and have the same genes in the same locus

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

What is protein Synthesis?

A

the production of proteins from the information contained within a cell’s DNA

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

What is Transcription?

A

where the DNA code is copied into a molecule called mRNA

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

What is Translation?

A

where the mRNA joins with an organelle called a Ribosome and the code it carried is used to synthesise a protein

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

What is RNA?

A

a single polynucleotide strand used in Protein Synthesis

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

What is mRNA?

A

made during transcription, carries the genetic code from DNA to Ribosomes

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

What is tRNA?

A

carries Amino Acids that are used to make proteins to the Ribosomes

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

Describe Transciption

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

Describe Translation

A
  • mRNA attaches to ribosome
  • codon on mRNA
  • binds to an anti-codon on tRNA
  • each tRNA brings a specific amino acid
  • sequence of codons/bases on mRNA determines the order of amino acids
  • formation of peptide bonds OR amino acids joined by condensation reactions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the function of Ribosomes in Protein Synthesis

A
  • Translation/construction of polypeptide(s)
  • Provide a binding site for mRNA OR mRNA attaches to ribosome
  • Provides binding sites for (two) tRNA molecules
  • Two amino acids are held close together
  • Formation of peptide bond(s)
  • (allows) assembly of amino acids into the sequence/primary structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe the role of tRNA in Translation

A
  • tRNA attaches to (specific) amino acids
  • tRNA (with amino acid) moves to the ribosome
  • The anticodon of tRNA binds to/forms hydrogen bonds with (a complementary) codon of mRNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the role of ATP in Translation

A
  • It activates the tRNA with an amino acid OR binds a specific amino acid with tRNA
  • The phosphorylation of tRNA OR creates a high energy bond which is transferred to the tRNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How is pre-mRNA turned into mRNA?

A

Introns are removed and Exons are spliced together before it exits nuclear envelope

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

What are three characteristics of the genetic code?

A

Degenerate
Non-overlapping
Universal

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

What does degenerate mean?

A

there are more possible triplet combinations that amino acids to be coded for

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

What does non-overlapping mean?

A

triplets don’t share bases

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

What does universal mean?

A

same specific base triplets code for the same amino acids in all living things

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

What is a Diploid cell?

A

a cell that has the normal number of chromosomes for the organism, 2n

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

What is a Haploid Cell?

A

a cell that has half the normal number of chromosomes for the organism, n

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

What is fertilisation?

A

when the sperm fuses with the egg

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

Give examples of Haploid cells

A

Sperm
Egg

29
Q

Describe the process of meiosis

A
30
Q

What processes during meiosis can lead to genetic variation?

A
  • Homologous chromosomes pair up / form bivalents
  • This can lead to the formation of a chiasma and crossing over can occur
  • (Crossing over) results in a new combination of alleles
  • Chromosomes can also align randomly
  • This is known as independent segregation/assortment
  • Which can produce varying combinations of chromosomes (alleles)
31
Q

Contrast Meiosis and Mitosis

A

Meiosis:
- produces haploid cells
- cells are genetically different
- produces 4 daughter cells
Mitosis:
- produces diploid cells
- cells are genetically identical
- produces 2 daughter cells

32
Q

Name 2 types of mutation

A

Substitution
Deletion

33
Q

What is Substitution?

A

one base is substituted with another

34
Q

What is deletion?

A

one base is deleted, causing a frame shift

35
Q

Describe the possible effects of a Substitution Mutation

A

may not always lead to a change in amino acid sequence because genetic code is degenerate
may cause a different amino acid to be coded for or a stop or start codon

36
Q

Describe the possible effects of a Deletion Mutation

A

will always cause a change is amino acid sequence
causes a frame shift

37
Q

What are Mutagenic Agents?

A

agents that increase the probability of a mutation occurring

38
Q

What is Chromosome non-disjuction?

A

a failure of the chromosomes to separate properly

39
Q

What is genetic Diversity?

A

the number of different alleles of genes in a species or population

40
Q

What is a Genetic Bottleneck?

A

an event that causes a big reduction in a population

41
Q

Describe the process of Natural Selection

A
  1. Not all individuals are as likely to reproduce as eacother, this is called differential reproductive sucess. Individuals that have an allele that increases their chance of survival are more likely to survive, reproduce and pass on their genes
  2. This mens that a greater proportuion of the next generation inherits the beneficial allele
  3. Those individuals will then be more likely to survive, reproduce, and pass on their alleles
  4. So the frequency of the beneficial allele in the population increases from generation to generation
  5. Over generations, this leads to evolution as advantagous alleles become more common in the population
42
Q

What are the 3 types of Adaptation?

A

Behavioural, Physiological, Anatomical

43
Q

What is a Behavioural Adaptation?

A

The ways an organism acts to increase its chance of survival

44
Q

What is a Physiological Adaptaion?

A

Processes inside an organism’s body that increase its chance of survival

45
Q

What are Anatomical Adaptations?

A

Structural features of an organism’s body that increase its chance of survival

46
Q

What is Directional Selection?

A

Where individuals with alleles for characteristics of an extreme type are more likely to survive and reproduce. This could be in response to an environmental change.

47
Q

What is Stabilising Selection?

A

Where individuals with alleles for characteristics towards the middle of the range are more likely to survive and reproduce. This occurs when the environment isn’t changing, and reduces the range of possible characteristics

48
Q

What is Disruptive Selection?

A

When both extreme traits are favored in an environment

49
Q

What is Phylogeny?

A

The study of the evolutionary history of groups of organisms

50
Q

What is Taxonomy?

A

the science of classification

51
Q

What is the order of Taxonomy?

A

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

52
Q

What is a binomial?

A

Genus Species

53
Q

What is courtship behaviour?

A

A bahaviour that is carried out by organisms to attract a mate of the right species

54
Q

Give examples of simple courtship behaviours

A

Releasing a chemical
Using sound
Visual display

55
Q

Give examples of complex courtship display

A

Dancing
Building

56
Q

Why is courtship behaviour specific?

A

to attract a mate of the opposite sex but same species that has reached sexual maturity to produce fertile offspring

57
Q

What is genome sequencing?

A

A way to determine the entire base sequence of an organism’s DNA which can then be compared to that of another species to see how closely related they are

58
Q

Why are amino acid sequences compared to determine how closely related 2 species are?

A

Amino acid sequence in a protein is coded for by DNA base sequence. related organisms will have a similar amino acid sequence in their proteins

59
Q

What are Immunological Comparisons?

A

comparing proteins using antibodies from eg a human and seeing if they will bind to a chimp cell

60
Q

What is Variation?

A

the difference that exists between individuals

61
Q

What is biodiversity?

A

the variety of living organisms in an area

62
Q

What is a habitat?

A

the place where an organism lives

63
Q

What is a community?

A

all the populations of different species in a habitat

64
Q

What is Species Richness?

A

a measure of the number of different species in a community- a simple measure of biodiversity

65
Q

What is an index of diversity?

A

a way of measuring biodiversity that takes into account the number of different speciess and number of individuals in each species

66
Q

What could farmers do that would reduce biodiversity?

A
  • clear wooland
  • remove hedgerows
  • use pesticides
  • use herbicides
  • monoculture
67
Q

How can biodiversity be increased and preserved?

A

Conservation Schemes

68
Q

What are the 3 types of mutations?

A
  1. nonsense- causes a stop codon to be made prematurely
  2. misense- causes the change of an amino acid
  3. Silent mutation- causes no change
69
Q

What is random selection?

A

AQA A Level Biology (4 decks)

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