Brainscape's Knowledge GenomeTM

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


See full index

GCSE Biology > B14 Genetics & Evolution > Flashcards

B14 Genetics & Evolution Flashcards

1
Q

What can random mutations (changes) in the DNA lead to?

A
  • Changes in the bacteria’s characteristics, e.g. being less affected by a particular antibiotic
  • This can lead to antibiotic-resistant strains forming as the gene for antibiotic resistance becomes more common in the population
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why are bacteria able to evolve quickly?

A
  • Bacteria are rapid at reproducing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why is the ability to resist antibiotics an advantage for bacterium?

A
  • It’s better able to survive, even in a host who’s being treated to get rid of the infection
  • So it lives longer and reproduces many more times
  • This increases the population size of the antibiotic-resistant strain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why are antibiotic-resistant strains a problem for people who become infected with these bacteria?

A
  • Aren’t immune to new strain
  • No effective treatment
  • Means that the infection easily spreads between people
  • Sometimes drug companies can come up with a new antibiotic that’s effective, but ‘super-bugs’ that are resistant to most known antibiotics are becoming more common
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Give an example of a ‘superbug’

A
  • MRSA
  • Relatively common
  • Hard to get rid of
  • Often effects people in hospitals & can be fatal if it enters their bloodstream
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why is the gene for antibiotic resistance becoming more common?

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

Why is the problem of antibiotic resistance becoming worse?

A
  • For the last few decades, we’ve been able to deal w/ bacterial infections pretty easily using antibiotics. The death rate from infectious bacterial diseases (e.g. pneumonia) has fallen dramatically
  • Problem of antibiotic resistance is getting worse because of the overuse & inappropriate use of antibiotics e.g. doctors prescribing them for non-serious conditions or infections caused by viruses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why must doctors only prescribe antibiotics when they need to?

A
  • The more often antibiotics are used, the bigger the problem of antibiotic resistance becomes
  • As in, it’s not that antibiotics actually cause resistance - they create a situation where naturally resistant bacteria have an advantage & so increase in numbers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why must you take all the antibiotics that a doctor prescribes for you?

A
  • Taking the full course makes sure that all the bacteria are destroyed, which means that there are none left to mutate & develop into antibiotic-resistant strains
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why shouldn’t antibiotics be overused in agriculture?

A
  • In agriculture, antibiotics can be given to animals to prevent them becoming ill & to make them grow faster
  • This can lead to the development of antibiotic-resistant bacteria in the animals which can then spread to humans e.g. during meat preparation & consumption
  • Increasing concern about the overuse of antibiotics in agriculture has led to some countries restricting their use
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why are drug companies developing new antibiotics?

A
  • The increase in antibiotic resistance has encouraged drug companies to work on developing new antibiotics that are effective against the resistant strains.
  • Unfortunately, the rate of development is slow, which means we’re unlikely to be able to keep up w/ the demand for new drugs as more antibiotic-resistant strains develop & spread
  • It’s also a very costly process
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is classification?

A
  • Organising living organisms into groups
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the significance of Carl Linneaus?

A
  • Traditionally, organisms have been classifed according to a system first proposed in the 1700s by Carl Linneaus, which groups living things according to their characteristics & the structures that make them up
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are living things divided into in the Linnean system?

A
  • First divided into 1) kingdoms (e.g. the plant kingdom)
  • The kingdoms are subdivided into smaller groups
    2) Phylum
    3) Class
    4) Order
    5) Family
    6) Genus
    7) Species
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the mnemonic for animal classification?

A
  • King Philip Came Over For Good Soup
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What helped to put forward new models of classification?

A
  • As knowledge of the biochemical processes taking place inside organisms developed and microscopes improved (which allowed us to find out more about the internal structures of organisms), scientists put forward new models of classification
17
Q

What is the significance of Carl Woese?

A
  • In 1990, Carl Woese proposed the three-domain system
  • Using evidence gathered from new chemical analysis techniques such as RNA sequence analysis, he found that in some cases, species thought to be closely related in traditional classification systems are in fact not as closely related as first thought
18
Q

How does the three-domain system work?

A
  • In the three domain system, organisms are first of all split into three large groups called domains:
    1) Archaea
    2) Bacteria
    3) Eukaryota
  • These are then subdivided into smaller groups - kingdom, phylum, class, order, family, genus, species
19
Q

What are archaea?

A
  • Organisms in this domain are primitive bacteria
  • Often found in extreme places such as hot springs & salt lakes
20
Q

What are bacteria?

A
  • This domain contains true bacteria like E.coli & Staphylococcus
  • Although they often look similar to Archaea, there are lots of biochemical differences between them
21
Q

What are eukaryota?

A
  • This domain includes a broad range of organisms including fungi, plants, animals & protists
22
Q

What is the binomial system?

A
  • In the binomial system, every organism is given its own two-part Latin name
23
Q

What is the first part of the Latin name given by the binomial system?

A
  • Refers to the genus that the organism belongs to
  • Gives you information on the organism’s ancestry
24
Q

What is the second part of the Latin name given by the binomial system?

A
  • Refers to the species
  • E.g. humans are known as Homo sapiens
  • ‘Homo’ is the genus
  • ‘sapiens’ is the species
25
Q

Why is the binomial system useful?

A
  • Used worldwide
  • Means that scientists in different countries who speak different languages all refer to a particular species by the same name - avoiding potential confusion
26
Q

What do evolutionary trees show?

A
  • How scientists think different species are related to each other (evolutionary relationships)
  • Common ancestors & relationships between species. The more recent the common ancestor, the more closely related the two species - & the more characteristics they’re likely to share
27
Q

How do scientists work out evolutionary relationships?

A
  • Scientists analyse lots of different types of data to work out evolutionary relationships
  • For living organisms, they use the current classification data (e.g. DNA analysis & structural similarities)
  • For extinct species, they use information from the fossil record

GCSE Biology (4 decks)

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