Brainscape's Knowledge GenomeTM

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


See full index

Biology GCSE > B15-Genetics and evolution > Flashcards

B15-Genetics and evolution Flashcards

1
Q

What is a fossil?

A

The remains of a plant or animal from millions of years ago that have been preserved

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

What are the 3 main ways fossils can form?

A

1-preserved traces(footprints/burrows/rootlet traces)
2-when parts of the organism doesn’t decay because one or more of the conditions for decay are absent
3-when parts of the organism are replaced by minerals as decay happens

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

What are the criteria for decay to occur?

A

Oxygen, bacteria(decomposers), correct temperatures

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

Why are fossils important?

A

To look at the anatomy of animals
How animals develop
All cells have a very similar chemistry-enzymes, DNA, ribsosomes etc.
Some organisms can be obseved evolving eg bacteria

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

Name the person who first discovered inherited characteristics are determined by ‘units’ passed on unchanged

A

Gregor Mendel

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

Why were Mendel’s ideas of inheritance not accepted during his time?

A

As chromosomes weren’t discovered

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

Who published the double helix structure of DNA?

A

Watson and Crick

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

Watson and Crick used whose work to find out the structure of DNA?

A

Franklin and Wilkins(but without Franklin’s permission)

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

Name the person who proposed the theory of evolution

A

Charles Darwin

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

Name the person who suggested changes that occur in an organism during its lifetime can be inherited

A

Jean-Baptiste Lamarck

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

On what mechanism is Darwin’s theory of evolution based on?

A

Natural selection

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

What is Darwin’s theory of evolution by natural selection?

A

All species have evolved from simple life forms

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

State 3 reasons why Darwin’s ideas were only slowly accepted

A

1-conflict with the wild belief that God made all living things
2-insufficient evidence
3-no mechanism to explain variation and inheritance

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

Who worked with Darwin to develop the theory of evolution?

A

Alfred Russel Wallace

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

Apart from evolution what are 2 other studies Wallace worked on?

A

Warning colouration in animals+theory of speciation

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

What is speciation?

A

The process by which 2 species evolve from a single original species by natural selection

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

Give the 6 steps in the process of speciation(how does a new species arise)

A

1-geographical isolation(eg flood divides an island in 2)
2-different selection pressures/conditions in the new environments
3-genetic variation(bc of mutations) within the groups
4-best adapted individuals to the new conditions survive, reproduce and pass on these favourable alleles
5-no interbreeding over time, groups become more different to each other
6-after a large amount of time, unable to interbreed successfully-they’re now separate species

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

Describe the 5 steps of fossilisation by mineralisation

A

1-organism dies and falls to the ground
2-flesh decays, leaving skeleton behind
3-bones are covered in sand/soil
4-bones become mineralised and turns into rock(fossil)
5-rock with fossil emerges due to geological movement(earthquake) and erosion occurs to reveal fossil

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

Give 4 reasons why the fossil record is incomplete

A

1-many earliest life forms are soft-bodied
2-most organisms didn’t become fossilised
3-most early fossils were destroyed by geological activity
4-many fossils are not yet found

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How is the fossil record helpful?

A

Shows how much organisms have changed and developed over time and can show the environment and climate then

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

Define extinction

A

Permanent loss of all members of a species

22
Q

State 3 causes of extinction

A

New predators, new diseases/pathogens, new successful competitors

23
Q

What causes mass extinction? Suggest 2 examples of this cause

A

Single catastrophic event that also affects climate over a long period(eg asteroid collision, volcanic eruption)

24
Q

Suggest a chain of events initiated by an asteroid collision that could lead to the extinction of dinosaurs

A

Asteroid impact causes huge fires and earthquakes–>volcanic eruptions–>dust/ash cloud covers atmosphere–>less sunlight reaches the Earth surface–>temp drop massively+plants die–>loss of food source led to other animals’ extinction

25
Q

What is antibiotic resistance?

A

Bacteria becoming resistant means it cant be killed by a certain antibiotic

26
Q

What causes antiobiotic resistance?

A

Random mutations in bacteria/bacteria sharing resistant genes

27
Q

Describe the steps in which a bacteria strain develops resistance to an antibiotic

A

1-mutation occurs in an individual bacterium within a population
2-it survives and reproduces rapidly, making more bacteria with its resistant gene
3-overtime all bacteria within the population have that gene

28
Q

Why can bacteria evolve quicker than other organisms?

A

Because bacteria can reproduce at a quick rate

29
Q

What is a genome?

A

The entire set of genes for an organism

30
Q

GIve 2 advantages of understanding the human genome

A

Identifying genes linked with inherited diseases , understanding human migration and evolution

31
Q

How 2 species of aniamls could have arisen from a common ancestor(speciation 6 marker)

A

Geographical separation; environmental differences, random mutation/variation, best adaptted in each aea survive breed and pass on allelses and genes, eventually the different populations can no longer succeessful breed with each other to produce fertile offspring

32
Q

Suggest 3 methods to prevent and slow down the development of antibiotic-resistant strains

A

1) Do not overuse antibiotics
2)patients finish anitbiotic course every time
3) restrict agricultural use of antibiotics

33
Q

Why must patients finish their course of antibiotics every time?

A

To ensure all bacteria are killed by the antibiotic so none can survive to mutate and develop resistance

34
Q

Suggest 3 ways in which a hospital can reduce the spread of antibiotic-resistant strains

A

Only use antibiotics if really needed, use strain-specific antibiotics, maintain high hygiene standards(wash hands between patient visits), isolate patients infected with resistant strain, vistors wash hands as they enter and leave

35
Q

Why is it difficult to develop new antibiotics to combat the appearance of new antibiotic-resistant strains of bacteria?

A

The development of new antibiotics is expensive and slow(won’t be able to keep up)

36
Q

What does classification of organisms mean?

A

Organisation of living things into groups based on thier similarities

37
Q

Name the person who developed the classification system

A

Carl Linnaeus

38
Q

State the 7 hierachical levels of the Linnaean classification system

A

Kingdom, phylum, class, order, family, genus, species

39
Q

Every organism has a scientific name using a binomial system-what does binomial mean?

A

2 names

40
Q

Which language does the binomial naming system use?

A

Latin

41
Q

The binomial name of an organism is made up of 2 words-what does each word represent of that organism?

A

The 1st word is the genus; 2nd word is the species

42
Q

What are the 3 rules of writing a binomial scientific name of species?

A

1st letter of the genus should be in capital; 1st letter of the species should be in lower case letter; both need to be in italics when printed or underlined when hand-written

43
Q

Why do we use the binomial naming system?

A

Every organisms’ names would vary in different language, but Latin is considered to be the old common language in which everyone can use/understand

44
Q

How many domains and kingdoms do scientists now consider in classifications?

A

3 domains, 6 kingdoms

45
Q

Based on what knowledge were the 3 domains set?

A

Different biochemistry of cell and ribosomes, and how cells reproduce differently

46
Q

What are the 3 domains?

A

Archaea, bacteria, eukaryota

47
Q

What are the 6 kingdoms?

A

Archaebacteria, eubacteria, protista, fungi, plants, animals

48
Q

How is classification helpful?

A

Helps us to understand evolutionary and ecological relationships, makes them easier to study, helps us recognise biodiversity and gives scientists a common language in which to talk about it

49
Q

Name the type of models that are used to show how different organisms are related

A

Evolutionary trees

50
Q

What aspects of knowledge would be considered when suggesting evolutionary relationships?

A

Similarities and differences in physical structures, genetics and biochemistry

Biology GCSE (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions