C2: Classification and biodiversity

Question 1

Define classification

Answer 1

Putting items into groups

Question 2

Name the heriarchy of taxons in order

Answer 2

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 3

How do scientists classify organisms

Answer 3

Based on their evolutionary history (phylogenetics)

Question 4

Define phylogenetic

Answer 4

Reflects evolutionary relatedness

Question 5

Name the three domains

Answer 5

Bacteria (or Eubacteria) which are the true bacteria.

The Archaea (or Archaeabacteria) include the extremophile prokaryotes.

Eukaryota which include all eukaryotic organisms i.e. animals, plants, fungi and protoctista.

Question 6

What do the organisms of each domain share

Answer 6

a distinctive, unique pattern of ribosomal RNA, which establishes their close evolutionary relationship

Question 7

Define extremophiles

Answer 7

Extremophiles exist in a wide variety of environmental conditions including extremes of temperature, pH, salinity and pressure

Question 8

Name the five kindoms

Answer 8

Prokaryotae, Protoctista, Plantae, Fungi, Animalia

Question 9

Describe Prokaryotae

Answer 9

Composed of prokaryotic cells, which lack a
nuclear envelope and membrane-bound organelles (the cell wall does not contain cellulose or chitin)

Question 10

Describe Plantae

Answer 10

multicellular eukaryotes, photosynthetic, cellulose cell wall

Question 11

Describe Animalia

Answer 11

nervous co-ordination; multicellular eukaryotes, no cell wall, heterotrophic

Question 12

Describe Fungi

Answer 12

Heterotrophic eukaryotes, cell walls of chitin, most have filaments called hyphae; reproduce by spores.

Question 13

Describe protoctista

Answer 13

Mainly single cell eukaryotes, no tissue
differentiation

Question 14

How to assess the relatedness of organisms using physical features

provide an example

Answer 14

The presence of Homologous structures - which have a similar arrangement of component parts and similar developmental origin but different functions.

eg:the pentadactyl limb in vertebrates(human arm,bat wing and whale flipper)

Question 15

What type of evolution is the pentadactyl limb

Answer 15

Divergent evolution

Question 16

Define divergent evolution

Answer 16

A common ancestral structure has evolved and performs different functions resulting in homologous structures (mostly)

Question 17

Define Analogous structures

Answer 17

Have a corresponding function and similar shape, but have a different developmental origin are not suitable to classify organisms

Question 18

Define Convergent evolution

Answer 18

Structures evolve similar properties but have different developmental origins resulting in analogous structures.

Question 19

Other than physical features what can also help assess relatedness

Answer 19

Genetic evidence like DNA sequences and amino acid sequences

Question 20

What is the benefit of using genetic profiling for species relatedness

Answer 20

can reduce the mistakes made in classification due to convergent evolution or sexual dimorphism

Question 21

Define a species

Answer 21

A group of organisms that can interbreed to produce fertile offspring

Question 22

What is the use of the binomial naming system

Answer 22

Its unambiguous - so one name for one species cannot be misinterpreted
It is universal - based on latin and used all over the world
Allows closely related species to be identified as they share Half a name

Question 23

How to use the binomial naming system

Answer 23

The Genus is the first word and has a capital letter

the species name comes second and is lowercase

( it is written in full the first time of writing then it can be abbreviated
when handwriting it should be underlined )
(NOT IMPORTANT)

Question 24

Define Biodiversity

Answer 24

the number of species and the number of individuals of each species in a given environment.

Question 25

Describe the two aspects of biodiversity

Answer 25

species richness - how many different species

species evenness - The number of individuals of each species living together in a community

Question 26

What factors affect biodiversity

Answer 26

Environmental (eg: light intensity)

Genetic (eg: succession and natural selection)

Human Influence (eg: deforestation, climate change, habitat destruction, overfishing and land misuse)

Question 27

Why are biodiversity hotspots around the equator and tropics

Answer 27

High light intensity all year ensures high energy input into the ecosystem, which means the ecosystem can support a large species richness and evennessa

Question 28

How can biodiversity be assessed in a habitat

Answer 28

Spearman’s diversity index

Question 29

What is the formula for spearmans diversity index

Answer 29

∑𝑛(𝑛−1)
D= 1− −−−−−−−−−−−−−−−−
𝑁(𝑁−1)

Question 30

What range must the simpsons diversity index be between

describe what a greater value means

Answer 30

0 - 1
the greater the value the greater the samples diversity

Question 31

How can biodiversity be assessed within a species

Answer 31

At a genetic level by looking at the variety of alleles in the gene pool of a population ( the proportion of polymorphic loci across the genome)

By determining the:
Number of alleles at a locus

Proportion of the population that have a particular allele

Question 31

Define polymorphism

Answer 31

The occurrence of more than one phenotype in a population that cannot be accounted for by mutation alone.

Question 32

Describe how polymorphism occurs

Answer 32

results from the presence of multiple alleles for the same gene in a gene pool.

Question 33

Describe the molecular assessment of biodiversity

Answer 33

Use genetic fingerprinting /profiling (same) to determine differences in introns;
small one base differences are SNPs (single nucleotide polymorphism)

Longer regions (20-40 base sequences) that are repeated many times are STRs (short tandem repeats)

The more differences the greater the biodiversity

Question 34

Define natural selection

Answer 34

The gradual process in which inherited characteristics become more or less common in a population, in response to the environment determining the breeding success of individuals possessing those characteristics

Question 35

Describe the process of natural selection in 7 stages

Answer 35

Mutation occurs

Mutation is expressed in phenotype so there is a change in physical appearance or behaviour

This variation is a selective advantage (competitive advantage) and outcompetes others during the intra-specific competition for resources

So they are most adapted to the environment and survive better

So they can more successfully reproduce

passing on advantageous alleles to offspring

allele frequency increases in future generations

Question 36

Name three different types of adaptations

Answer 36

Anatomical
Physiological
Behavioural