Module 4.3 - Classification and Evolution

Question 1

What is taxonomy?

Answer 1

The study of classification.

Question 2

What is the taxonomic hierarchy?

Answer 2

(Domain) Kingdom, Phylum, Class, Order, Family, Genus, Species.

Question 3

What are the five kingdoms of organisms?

Answer 3

Prokaryotae, protoctista, fungi, plantae and animalia.

Question 4

What are the general characteristics of the organisms in the Prokaryotae kingdom?

Answer 4

> Prokaryotic
Unicellular
No nucleus
Less than 5mm.

Question 5

What are the general characteristics of the organisms in the Protoctista kingdom?

Answer 5

> Eukaryotic cells
Usually live in water
Single-celled or simple multicellular organisms.

Question 6

What are the general characteristics of the organisms in the Fungi kingdom?

Answer 6

> Eukaryotic
Chitin cell wall
Saprotrophic (absorb substances from dead or decaying organisms).
Single-celled or multicellular organisms.

Question 7

What are the general characteristics of the organisms in the Plantae kingdom?

Answer 7

>Eukaryotic 
>Multicellular
>Cell walls made of cellulose.
>Can photosynthesise
>Contain chlorophyll
>Autotrophic - produce their own food

Question 8

What are the general characteristics of the organisms in the Animalia kingdom?

Answer 8

> Eukaryotic
Multicellular
No cell walls
Heterotrophic (consumes plants and animals).

Question 9

What is the nomenclature (naming system) used for classification called?

Answer 9

The binomial system.

Question 10

What is phylogeny?

Answer 10

The study of the evolutionary history of groups of organisms and tells us who’s related to whom and how closely related they are.

Question 11

What is some of the evidence used to see how related some organisms are?

Answer 11

> Molecular evidence - the similarities in proteins and DNA. More closely related organisms will have more similar molecules.
Embryological - the similarities in the early stage of an organism’s development.
Anatomical - similarities in structure and function of different body parts.
Behavioural - similarities in behaviour and social organisation of organisms.

Question 12

What problematic evidence was solely used in original classification?

Answer 12

Observable features

Question 13

What lead to new discoveries in the classification of organisms?

Answer 13

> New Technologies - Provided new DNA techniques (better microscopes).
Scientists can share their new discoveries in meetings and scientific journals.

Question 14

How does the three domain system differ from the old system of the five kingdoms?

Answer 14

The new system has three domains - large super kingdoms that are above the kingdoms in the taxonomic hierarchy.

Question 15

What are the 3 domains?

Answer 15

Archaea, Bacteria and Eukarya.

Question 16

What evidence was proposed to support the 3 domain system?

Answer 16

> Molecular evidence - The enzyme RNA polymerase is different in bacteria and archaea. Archaea have similar histones to Eukarya.
Cell membrane evidence - The bonds of the lipids in the cell membranes of bacteria and archaea are different. The development of flagellae are also different.

Question 17

What do scientists now believe about the evolution of archaea and bacteria?

Answer 17

They evolved separately and that the archaea are more closely related to eukarya than bacteria.

Question 18

What is variation within a species known as?

Answer 18

Intraspecific variation.

Question 19

What is variation between species known as?

Answer 19

Interspecific variation.

Question 20

What is continuous variation?

Answer 20

When the individuals in a population vary within a range - there are no distinct categories.

Question 21

Give some examples of continuous variation?

Answer 21

>Mass
>Number of leaves,
>Width
>Length
>Height
>Milk Yield.

Question 22

What is discontinuous variation?

Answer 22

When there are two or more distinct categories - each individual falls into only one of these categories, there are no intermediates.

Question 23

Give some examples of discontinuous variation?

Answer 23

> Blood group
Colour
Antibiotic resistance
Seed shape (e.g. some plants have smooth seeds and some have wrinkled)
Pigment production (some types of bacteria can produce a coloured pigment, others can’t).

Question 24

What are the genetic factors that affect variation?

Answer 24

> Different species have different genes.
1)Individuals of the same species have the same genes but different alleles which makes up their genotype.
2)The differences in genotype result in variation of the phenotype (physical characteristics).
You inherit genes from your parents so genetic variation is inherited.

Question 25

Give two examples of a variation caused only by genetic factors?

Answer 25

>Blood group in humans | >Antibiotic resistance in bacteria.

Question 26

How do environmental factors differ from genetic factors?

Answer 26

They are caused by differences in environment and can change over an organism's life.

Question 27

Give two examples of when both genetic and environmental factors cause variation?

Answer 27

>Height >Flagellum - Genes determine if a microorganism can grow a flagellum but some will only start to grow in certain environments.

Question 28

What does standard deviation tell you?

Answer 28

How much the values in a simple sample vary. It's a measure of the spread of values about the mean.

Question 29

What does a large standard deviation mean?

Answer 29

Means the values in the sample vary a lot.

Question 30

What is the formula for standard deviation?

Answer 30

sd =√Σ(x-mean)/n-1

Question 31

What benefits does an organism have if it is well adapted to its environment?

Answer 31

Increases its chance of survival and reproduction and also the chances of its offspring reproducing successfully.

Question 32

What is a behavioural adaptation?

Answer 32

Ways an organism acts that increase its chance of survival.

Question 33

What is a physiological adaptation?

Answer 33

Processes inside an organism's body that increase its chance of survival.

Question 34

What is a anatomical(structural) adaptation?

Answer 34

Structural features of an organism's body that increases its chance of survival.

Question 35

Give examples of a behavioural adaptation?

Answer 35

>Possums sometimes 'play dead' if they're being threatened by a predator to escape attack. >Scorpions dance before mating making sure they attract a mate of the same species.

Question 36

Give examples of a physiological adaptation?

Answer 36

>Brown bears hibernate - lower their rate of metabolism over winter which conserves energy so don't need to look for food when it's scarce. >Some bacteria produce antibiotics - kill other species of bacteria in the area meaning less competition.

Question 37

Why can organisms from different taxonomic groups have similar features even if they're not closely related?

Answer 37

The organisms have evolved in similar environments and to fill similar ecological niches.

Question 38

What are the difference between placental mammals and the marsupial mammal that diverged from them?

Answer 38

Placental mammals - >Have a longer gestation period. >Develop a placenta during pregnancy. >Born fully developed. Marsupial mammals - >Short gestation period. >Don't develop a full placenta. >Born early in their development and climb into their mother's pouch and attach to a teat receiving milk as they continue to develop.

Question 39

Even though marsupial and placental moles aren't closely related due to evolving on different continents, what is similar and why?

Answer 39

Share similar anatomical features because they both evolved in similar environments.

Question 40

What are the adaptations that both marsupial and placental moles have?

Answer 40

>Live in tunnels in the ground >Burrow to reach their food supply >Small, nonexistent eyes for they live underground. >No external ears, streamlined head >Claws specialised for digging >Tube shaped body and cone shaped head to push through soil/sand.

Question 41

What were Darwin's 4 key observations that contributed to his theory of evolution?

Answer 41

>Organisms produce more offspring than survive. >There's variation in the characteristics of members of the same species. >Some characteristics can be passed on from one generation to the next. >Individuals that are best adapted to their environment are more likely to survive .

Question 42

What were Wallace's contributions?

Answer 42

>Independently came up with the idea of natural selection. >Published their papers on evolution together. >Provided observations to support the theory.

Question 43

How can you use fossil record evidence to support evolution?

Answer 43

By arranging fossils in chronological order, gradual changes in organisms can be observed that provide evidence of evolution.

Question 44

How can you use DNA evidence to support evolution?

Answer 44

>Organisms that diverged away from each other more recently have more similar DNA as less time has passed for changes in the DNA sequence to occur. >Looking at differences in mitochondrial DNA to see how closely related organisms are.

Question 45

How can you use molecular evidence to support evolution?

Answer 45

>Similarities in other molecules such as comparing the sequences of amino acids in proteins and comparing antibodies. Organisms that have diverged away from each other more recently have more similar molecules - less time for changes in proteins and other molecules to occur.

Question 46

Describe how the evolution of pesticide resistance can be explained by natural selection?

Answer 46

1) There is variation in a population of insects. Genetic mutations create alleles that make some insects naturally resistant to a pesticide. 2) If the population of insects is exposed to that pesticide only then the individuals with resistance will survive to reproduce. 3) The alleles which cause the pesticide resistance will be passed on to the next generation, and so the population will evolve - more individuals will carry the allele than in the previous generation.

Question 47

What could be the implications for humans of the evolution of pesticide resistance?

Answer 47

>Crop infestations with pesticide-resistant insects are harder to control - some insects may be resistant to multiple pesticides, by the time the farmer has figured out which pesticide kills the insect the crop may already be destroyed, farmers may have to use broader pesticides that could kill beneficial insects. >If disease-carrying insects (e.g. mosquitos) become pesticide resistant, the spread of disease could increase. >A population of insects could evolve resistance to all pesticides in use. To prevent this new pesticides need to be produced, this takes time and costs money.

Question 48

How does the evolution of drug resistance have implications for humans too?

Answer 48

>Infections caused by drug-resistant microorganisms are harder to treat - especially if it's resistant to lots of different drugs, it can take doctors a while to figure out which drugs will get rid of the infection and in that time the patient could become very ill or die. >A pathogen could become resistant to all the drugs we currently use against. To prevent this new drugs need to be developed and this takes time and money.