M4C10 - Classification and evolution

Question 1

What is classification in biology?

Answer 1

The process of naming and organising organisms into groups based on their characteristics.

Question 2

Why do scientists classify organisms?

Answer 2

To identify species
To predict characteristics
To find evolutionary links

Question 3

What are the 7 taxanomic groups developed by Carl Linneus?

Answer 3

Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 4

What are the five kingdoms of organisms?

Answer 4

• Animalia
• Plantae
• Fungi
• Prokaryotae
• Protoctista (any eukaryotic organism that isn’t plant, animal or fungi).

Question 5

What features are used to classify Animalia?

Answer 5

-Multicellular
-Eukaryotic
-Heterotrophic

Question 6

What features are used to classify Plantae?

Answer 6

-Multicellular
-Eukaryotic
-Contain chloroplasts
-Autotrophs

Question 7

What features are used to classify Fungi?

Answer 7

-Unicellular or multicellular
-No chloroplasts or chlorophyll
-Cell wall made of chitin
-No mechanisms for locomotion

Question 8

What features are used to classify protoctista?

Answer 8

-Eukaryotic
-Most are unicellular, few are multicellular.
-Autotrophic or heterotrophic

Question 9

What features are used to classify prokaryotae?

Answer 9

-Unicellular
-No visible feeding mechanism
-No nucleus or membrane bound organelles

Question 10

Describe the current classification system proposed by Carl Woese

Answer 10

Added ‘Domain’ to the classification system above Kingdom

Question 11

What are the 3 domains under the ‘3 domain system’ proposed by Carl Woese

Answer 11

Archaea, Bacteria, Eukarya

Question 12

Describe the domain Archaea

Answer 12

-70s ribosomes
-RNA polymerase of different organisms contains between 8 and 10 proteins.

Question 13

Describe the domain Bacteria

Answer 13

-70s ribosomes
-RNA polymerase contains 5 proteins

Question 14

Describe the domain Eukarya

Answer 14

-80s ribosomes
-RNA polymerase has 12 proteins

Question 15

What are the 6 kingdoms of classification propsed by Carl Woese (currently used)

Answer 15

Animalia
Plantae
Fungi
Protoctista
Eubacteria (Most bacteria)
Archaebacteria (ancient, live in extreme environments).

Question 16

What is the binomial system?

Answer 16

A naming system where each species is named with a genus name followed by a species name.

Question 17

What is an advantage of the binomial naming system?

Answer 17

Its universal and doesn’t vary between languages.

Question 18

What is phylogeny?

Answer 18

Evolutionary relationships between organisms.

Question 19

What are some advantages of phylogeny?

Answer 19

-Can confirm or change taxonomic groups.
-Hierarchial nature of Linnaen classification can be misleading as it implies different groups within the same rank are equivilent.

Question 20

What is a phylogenetic tree?

Answer 20

Diagram used to represent evolutionary relationships between organisms. Produced by looking at organisms physical similarities as well as genetic make up.

Question 21

What is molecular phylogeny?

Answer 21

The analysis of molecular differences in organisms to determine their evolutionary relatedness.

Question 22

Describe Darwin’s theory of natural selection

Answer 22

A random mutation occurs which produces an advantageous allele.
Organisms with this allele are more likely to survive and reproduce.
Therefore, advantageous allele will be passed onto to future generations.

Question 23

How did Alfred Wallace contribut to the acceptance of Darwin’s theory of natural selection?

Answer 23

He had similar ideas to Darwin and they published a paper together which increased the weight of the evidence.

Question 24

How do fossils provide evidence for evolution?

Answer 24

-Fossils show changes over time
-There are ways to date fossils
-The simplest species are found in the oldest rocks
-Many fossils are of organisms that no longer exist
-It is possible to compare the DNA extracted from some fossils

Question 25

What are some issues with fossils as evidence for evolution?

Answer 25

The record is not complete: -Many organisms are soft-bodied and decompose quickly before they have a chance to fossilise. -Conditions for fossils to form are often not present. -Many fossils have been destroyed by Earth's movements.

Question 26

What is a homologous structure and how can they provide evidence for divergent evolution.

Answer 26

A structure that appears superficially different in different organisms but has the same underlying structure. Divergent evolution describes how different species have evolved from a common anscestor each with a different set of adaptations.

Question 27

Describe how DNA can be used to provide evidence to support the theory of evolution by natural selection.

Answer 27

-DNA is found in all organisms. -Some sequences are highly conserved. -Comparison of DNA between species. -Similar base sequence indicates recent common ancestor.

Question 28

Explain how biological molecules can provide evidence that species have evolved (biochemistry)

Answer 28

-In samples from two species sequence similarity in any of nucleic acid, DNA, mtDNA, RNA can imply an evolutionary relationship. -Difference / divergence in sequence implies evolutionary distance. -In the same protein (haemoglobin) from two species, amino acid/ primary sequence similarity implies evolutionary relationship. -Difference / divergence in sequence implies evolutionary distance.

Question 29

What is interspecific variation?

Answer 29

Variation between members of different species

Question 30

What is intraspecific variation?

Answer 30

Variation between organisms within a species

Question 31

What are the genetic causes of varitation?

Answer 31

Alleles Mutations Meiosis

Question 32

What are the characteristics of a normal variation?

Answer 32

-Mean, median and mode are the same -Bell shape -Most values lie close to the mean value -50% of values are above the mean and 50% of values are below the mean.

Question 33

What are anatomical adaptations?

Answer 33

Physical adaptations, either external or internal, that improve survival chances.

Question 34

What are behavioural adaptations?

Answer 34

The way an organism acts. These can be inherited or learnt from their parents.

Question 35

What are physiological adaptations?

Answer 35

Processes that take place inside an organism

Question 36

What are some examples of anatomical adaptations?

Answer 36

-Body covering (feathers, scales) -Camouflage -Teeth -Mimicry -Adaptations of Marram grass (xerophyte)

Question 37

What are some examples of behavioural adaptations?

Answer 37

-Survival behaviours (playing dead) -Courtship -Seasonal behaviours -Migration -Hibernation

Question 38

What are some examples of physiological adaptations?

Answer 38

-Poison production -Antibiotic production -Water holding

Question 39

What are analogous structures?

Answer 39

Structures adapted to perform the same function but have a different genetic origin.

Question 40

What is convergent evolution?

Answer 40

When unrelated species begin to share similar traits.

Question 41

What is a selection pressure?

Answer 41

Factor that contributes to causing evolution

Question 42

What is evolution?

Answer 42

The process by which the frequency of alleles in a gene pool changes over time due to natural selection.

Question 43

What happens when two populations become reproductively isolated?

Answer 43

New species will be formed due to accumulation of different genetic information.

Question 44

What evidence did Darwin use to support the theory of evolution?

Answer 44

Observations of different finch types on the Galapagos Islands.

Question 45

Describe the process of bacteria becoming antibiotic resistant and give an example

Answer 45

A mutation causes bacteria to become resistant to an antibiotic. When bacteria are exposed to an antibiotic, resistant individuals survive and reproduce, and non-resistant individuals die. Over time the resistant population increases. -MRSA has developed resistance to many antibiotics.

Question 46

Discuss the implications of the over-use of antibiotics when people do not show symptoms.

Answer 46

-Antibiotic is selective pressure. -Some bacteria have resistance. -When exposed most-resistant survive, surviving bacteria continue to reproduce to make a resistant population. -Over many generations there is an increase in proportion of resistant bacteria under continued antibiotic pressure. Antibiotic becomes ineffective.