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Wjec Biology Unit 2 > 2.1 > Flashcards

2.1 Flashcards

1
Q

Identify some sources of error when investigating the biodiversity of animals

A
  • some easier to catch than others
  • misidentification
  • recounting
  • move around
  • camouflaged
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2
Q

What is classification

A

Organisation of every living thing into groups

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3
Q

Aim of classification

A

Group organisms to reflect how closely they are related in terms of their evolutionary relationships

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4
Q

What does it mean that classification is hierarchical

A

Large groups are split into groups of decreasing size

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5
Q

What does is mean that classification is phylogenetic

A

Organisms in the same group are more closely related

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6
Q

What does it mean that classification is discrete

A

An organism cannot belong to more than one group at the same taxonomic level

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7
Q

What is a group called

A

Taxon

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8
Q

List the hierarchy of taxa

A 
Kingdom
Phyla
Classes
Orders
Families 
Genera
Species
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9
Q

What are the three domains

A

Eubacteria
Archaea
Eukarya

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10
Q

Eubacteria

A

True bacteria

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11
Q

Archaea

A

Prokaryotic but extremophiles

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12
Q

Eukarya

A

Eukaryotic organisms

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13
Q

What is an extremophile

A

Lives where environmental conditions are harsh

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14
Q

Where does the evidence for the three lineages come from

A

Studies on ribosomal RNA

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15
Q

What is a species

A

Group of organisms with similar characteristics that can interbreed to produce fertile offspring

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16
Q

Why is a hybrid sterile

A

Gametes of the two species have different chromosome numbers so chromosomes cannot pair up at start of meiosis - cant make gametes

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17
Q

What are the two parts of the binomial name of a species

A

Generic name and species name

Italicized

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18
Q

Generic name

A

Capitalised

Gives genus

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19
Q

Species name

A

Lower case

Species

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20
Q

What is a phylogenetic tree

A

Diagram that represents the evolutionary pathways leading to different species

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21
Q

What is the axis and tree branches of a phylogenetic tree

A

Axis is time

Tree branches as time moves forward

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22
Q

What does a junction represent in a phylogenetic tree

A

Common ancestor of the organism that branch from it

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23
Q

What is a clade

A

Group of branches from one common ancestor

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24
Q

What biological polymers can be used to establish relatedness and why can they be used

A

DNA, RNA or protein

They have different subunits which can be compared and number of differences counted

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25
How are mutations owing to differences in biological polymers
They lead to differences in the amino acid sequence of proteins
26
What can gel electrophoresis fo
Separate fragments of DNA and proteins Allows small fragments to move further and electrical charge causes movement of negatively charged DNA fragments to positive electrode
27
What is produced when using gel electrophoresis
Banding pattern that can be used to compare
28
What is morphology
Looking at the shape and form of an organism
29
What used to be the main evidence that naturalists had to classify organisms and construct phylogenetic diagrams before biochemical analysis
Morphology
30
What is convergent evolution
Ancestors have adapted themselves to same environmental pressure but from different developmental origins
31
What is a homologous structure
Structures in different species with a similar anatomical position and development origin derived from a common ancestor Similar structure different functions Related organisms
32
Example of homologous structure
``` Pentdactyl limb Mammals - grasping Birds - flight Whales and dolphins - swimming Moles - digging ```
33
What is an analogous structure
Corresponding function and similar shape but different developmental origin Unrelated organsims
34
What is biodiversity
Describes the species richness and species evenness in a given area
35
What is species richness
Number of species
36
What is species evenness
Number of individuals of each species
37
What does it mean that biodiversity varies spatially
Increases going from poles towards the equator
38
Why does biodiversity vary spatially
More UV light - higher rate of mutation so more rapid evolution More species types - more habitats and niches More stable temperature range and water availability- more favourable conditions for survival More species and individuals so higher competition so narrower exploitation of niches so harder to move our the area
39
Factors affecting biodiversity
Human activity Natural selection Succession
40
What is succession
Composition of a community changes over time as different species colonise
41
2 ways an area can be sampled
Gridding or by a transect
42
When is gridding used to sample
Two areas are to be compared
43
When is a transect used when sampling
Gradual change in the environment
44
Why is random sampling important
Avoids unconscious sampler bias which increases reliability of data
45
How is random sampling achieved?
Random number tables are used to generate rand co-ordinates for a gridded area and the quadrats placed at those co-ordinates only Sampling along transect done at fixed distance
46
What are the 5 kingdoms
``` Plantae Animalia Fungi Prokaryotes Protoctista ```
47
Technique used to sample terrestrial animals
Mark-release-recapture | Lincoln index
48
Method used for Lincoln index
Animals captured and marked and then released Once they have had a change to reintegrate with the population the traps are reset Pop size = no in sample 1 x no in sample 2 / no in marked sample
49
Important points when using Lincoln index
* animals cannot be harmed or made more visible to predators | * assume that no births/deaths/immigration/ emigration have occured
50
Technique used to sample freshwater invertebrates
Kick-sampling and Simpson's index
51
Method used to sample freshwater invertebrates
Collect and identify invertebrates from a given area using a quadrat and a net Kick/ rake the area for a set period and collect invertebrates in a net downstream Release invertebrates carefully Use Simpsons index to calculate diversity
52
Technique used to sample plants
Quadrats and transects
53
Method used to sample plants
Estimate percentage area cover of different plants using quadrat divided into 100 Measure plant diversity by counting number of plants in a quadrat
54
Main hazards in field work
* biting and stings - can scratch or cause allergic reaction - wear insect repellent and protective clothing * slippery surfaces - strains and sprains - footwear with grip
55
How can genetic biodiversity be assessed
Determining the number or alleles at different loci within a given species Taking samples of DNA from individuals in the population and determining DNA sequences by using gel electrophoresis to produce genetic fingerprints
56
What are alleles
Different forms of genes
57
What are loci
Position of genes on a chromosome
58
What is polymorphism
Species has a number of different forms
59
What is genetic polymorphism
Many different alleles for the same gene leading to different forms of the same organism
60
How can genetic polymorphism be assessed
Determining the number of alleles at any one gene locus and the proportion of the population that has a particular allele
61
How does biodiversity arise
By natural selection
62
Steps in natural selection
1. Mutations cause variations in individuals that can be inherited 2. Offspring are overproduced which leads to intraspecific competition 3. The variation that give a selective advantage means the individual is better fitted to survive selection pressure 4. Individuals that have selective advantage survive and reproduce which passes the alleles to offspring 5. Over many generations the allele frequencies of favourable variation increases
63
What is a selection pressure and give examples
Something that causes the death of an organism | Eg predation, disease or climate
64
Three types of adaptations
Anatomical, physiological, behavioural
65
Anatomical adaptation
Physical features
66
Physiological adaptations
Internal body process to regulate and maintain homeostasis
67
Behavioural adaptations
In response to some external stimulus to survive

Wjec Biology Unit 2 (5 decks)

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