Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology Edexcel B A Level > Topic 3 Classification And Biodiversity > Flashcards

Topic 3 Classification And Biodiversity Flashcards

1
Q

4 eukarya kingdoms

A

Animalia
Plantae
Fungi
Protoctista

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

3 facts about Plantae

A
  • autotrophs
  • contain chlorophyll for photosynthesis
  • cellulose cell walls
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

3 facts about Fungi

A

-saprophytic
- chitin cell wall
- reproduce by spores

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

3 facts about Animalia

A
  • heterotrophic
  • capable of whole body movement
  • no cell walls
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are Protoctista ?

A
  • diverse group of eukaryotes that cannot be classified as animals, plants or fungi.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are autotrophs?

A

Plantae
Make their own food

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

What are heterotrophs?

A

Animalia
They eat others for food

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

What are saprophytes?

A

Fungi
Live off dead organisms using extra cellular digestion

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

What are the Taxonomic groups?

A

D Keep Ponds Clean Or Froggies Get Sick / Daddy King Philip Came Over For Great Sex

Domain Kingdom Phylum Class Order Family Genus Species

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

What is the definition of a species?

A

A group of organisms with similar characteristics that interbreed to produce fertile offspring

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

What is sexual dimorphism?

A

Male and female look very different
Have different physical features

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

What are morphological species?

A

Organisms categorised together as a species based on their physical features

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

Advantage of morphological species?

A

Easy

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

Disad of morphological species

A

Problem of sexual dimorphism

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

Limitations of species models?

A
  • Need to find evidence
    Rare to see them mating/ Expensive to setup sreeding programs
  • Seperate species can produce fertile offopring
  • mary organismes dont reproduce sexually
  • fossil organism, cannot reproduce but need to be classified
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a phylogeny

A

Study of evolutionary relationships
Closeness of relationship between organisms which create an evolutionary tree

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

What is the redefined species definition? Based on …

A
  • structural and biochemical resemblance
  • capability to interbreed and produce fertile offspring
  • they do NOT interbreed w other species
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the 3 domains

A
  • bacteria
  • eukaryotes
  • archaea
    (ABE)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How are scientific ideas evaluated? (3 mark)

A
  • peer reviewed by other scientists
  • scientific findings published
  • idea presented at scientific conference
    (- repeat experiments to validate results)
    (- sharing on the media, internet)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the biochemical differences between domains?

A

Cell wall compositions
(e.g. peptidoglycan in bacteria)

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

What are the evidence for the three domains?

A

RNA sequence and sensitivity to antibiotics

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

What is the main limitation of biological species concept?

A

inapplicable to: (1) fossil species; (2) organisms reproducing asexually

23
Q

How to classify organism groups of species? 3 steps

A
  1. Evolutionary relationships between organisms and their ancestors
  2. Classifying species into groups using their shared features derived from ancestors
  3. Arranging groups into a hierarchy
24
Q

What is the definition of evolution?

A

Organisms with different genotypes lead to different phenotypes within a specific environment.
Advantage adaptations best suited to the environment will be passed onto the next generation (alleles)

25
What are sources of genetic variation?
Random fertilisation Crossing over Independent assortment Mutations
26
How does natural selection give rise to adaptations?
Genetic variation between species due to mutations (and other reasons), **selection pressure** favours certain alleles. Those with beneficial alleles survive and reproduce, **passing on** beneficial alleles to offspring and over generations lead to **adaptation**.
27
What is the definition of niches? 2 marks
Role of an organism (1) In its habitat / ecosystem (1) Eg Where a species lives, what it eats, its predators, and how it interacts with non-living surroundings
28
What are 3 adaptations for developing a good niche?
Anatomical Physiological Behavioural
29
What are anatomical adaptations?
Adaptations involving actual structure and form of an organism
30
What are physiological adaptations?
Adaptations that involves how the organism works eg biochemical pathways, enzymes and metabolisms
31
What are behavioural adaptations?
Specific types of behaviour that make organisms better adapted to their surroundings and more likely to survive
32
What is allopatric speciation
When two populations (plants or animals) are totally separated from each other by a **geographical** barrier (eg river, mountain) , preventing interbreeding Geographical isolation
33
What is the definition of speciation?
Process where one species may evolve from another often due to isolation
34
How does speciation happen?
Change of conditions, adaptations may not be advantageous There is a different selection pressure Natural selection continue and lead to formation of new species
35
What is the sympatric speciation? (2 marks)
- Formation of new species - while both still living in the same location (mixing freely but become **reproductively isolated**) (Due mechanical, ecological, behavioural or temporal isolation)
36
What are 4 things that lead to sympatric speciation?
- ecological isolation (eg half lives in water and on land) - temporal (when 2 populations mate at different times of the year) - mechanical isolation (physically can’t reproduce) - behavioural (
37
what is the biggest group of pathogen?
bacteria
38
Who discovered the first antibiotic penicilin?
Alexander Flemming
39
What are Gram positive bacteria?
Thick peptidoglycan walls stains purple with crystal violet susceptible to antibiotics PPP: Positive Purple Peptidoglycan
40
what are gram negative bacteria?
thin peptidoglycan wall with additional lipid layer prevents staining impermeable to antibiotics
41
How did bacteria gain resistance to antibiotics?
1% of bacteria mutate most bacteria die under antibiotics except mutated ones, advantageous so keep producing it multiplies via mitosis eventually the whole population is resistant
42
What are issues with antibiotics?
- they are too widely prescribed - people dont complete courses of antibiotics -
43
How to tackle issues with antibiotics?
- reduce use - better education
44
How do scientists classify species?
- ecological - mate recognition - evolutionary species - genetic species
45
what are evidence for the 3 domains?
- different nucleotide and RNA sequence - cell membrane lipid structure - cells walls not of peptidoglycan
46
how can organisms be classified into taxonomic groups? 2 marks
- organisms share similar characteristics placed in a group - molecular phylogeny - dna profiling
47
How can scientists classify an organism as a new species? 4 mark
- compare physical characteristics - observe behaviour - **molecular phylogeny** (Use DNA sequencing / biochemistry) - unable to breed with or their species and produce fertile offspring
48
Why is it difficult to classify a newly discovered organism as a separate species? 2 marks
- some species can interbreed and produce fertile offspring - species are evolving overtime - there is variation within the species
49
Why can flies develop resistance so quickly?
They have short life cycle Flies produce lots of offspring
50
Explain the evidence that led to three-domain system, replacing five kingdom classification. 3 marks
- molecular phylogeny - able to identify similarities and differences between bacteria and archaea - eg membrane structure, proteins etc
51
Explain how evolution can occur through natural selection. (3 marks)
- genetic mutation / variation - some organisms are better adapted to survive - reproduce - alleles passed on
52
Compare and contrast allopatric and sympatric speciation. (4 marks)
(write heading in exam) Similarities: - reproductive isolation - one original population - absence of gene flow Difference: Allo / Symp - requires geographic isolation / does not - does not / diff food and behaviour
53
Given that Tasmanian wolves are marsupial mammals and grey wolves are placental. Explain why grey wolves and close relatives are found in many parts of the world, while Tasmanian wolves only survived in isolated islands. (3 marks)
- higher survival as a placental mammal - since offspring are born more developed, while marsupials are born very small - grey wolves outcompete Tasmanian wolves, TM can only survive where less competitors also inhabit
54
Why are there more strains of different antibiotic for antibiotic discovered longer ago?
More time for resistant strains to appear

Biology Edexcel B A Level (22 decks)

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