Chapter 4 - Evolution

Question 1

What is the definition of Evolution by Natural Selection?

Answer 1

Evolution is a slow continual change of organisms over a very long time through a natural process (without human interference)

Question 2

What is an alternative theory to Evolution?

Answer 2

Creationism

Question 3

What do creationists argue? Why can’t we link everything through Evolution?

Answer 3

A designer is responsible for everything and that if Evolution is real then you must be able to link everything.
Not everything dies when/where it can be fossilized.

Question 4

What is LUCA?

Answer 4

The Last Universal Common Ancestor

Question 5

Which factors may cause a species to become extinct if they don’t adapt to them?

Answer 5

Increased competition
Changes in the environment
New diseases
New predators

Question 6

Name Darwin’s key observations

Answer 6

All living things produce more offspring than survive to adulthood
In spite of this, population sizes remain roughly constant
Variation exists among species
Characteristics can be passed from one species to the next

Question 7

What is the main evidence for Natural Selection?

Answer 7

Fossils

Question 8

What is Taxonomy? Who invented it?

Answer 8

The study of classification

Carl Linnaeus

Question 9

What is a genus?

Answer 9

A larger group that all species are placed in. It’s like a surname

Question 10

What makes each genus different?

Answer 10

All of the species possess similarities which put them in a genus which make them distinct from other genera. The genus is like the surname

Question 11

A horse and a donkey are in the same genus. They share common characteristics. Are they of the same species? (Clue: think about the potential for breeding)

Answer 11

No. They would mate to produce a mule - a sterile animal

Question 12

Name the hierarchy of classification

Answer 12

Domain, Kingdom, Phyllum, Class, Order, Family, Genus, Species
D, K, P, C, O, F, G, S

Question 13

Name the five Kingdoms

Answer 13

Animals, Plants, Bacteria (monera) Fungi, Protists (the bag of leftovers where they don’t fit into any of the others)

Question 14

Name the three domains for Bacteria. Describe each of them.

Answer 14

Prokaryotes, Eukaryotes and Archea
Prokaryotes - small, no membrane bound organelle, nucleotide/chromosomes, have no histones
Eukaryotes - large, membrane bound organelle, nucleus, have histones
Archea - Small, nucleus(is a prokaryote, have proteins similar to histones

Question 15

What are the only human ancestors called? What evidence is there to prove they existed?

Answer 15

Hominids

Fossils

Question 16

What is anthropology?

Answer 16

The study of human behavior

Question 17

How can we use anthropology to find out about out ancestors?

Answer 17

We use chimps to find out about our ancestors

Question 18

What is the difference between chimps’ ancestors and ours?

Answer 18

We used stone tools

Question 19

How can we use archeology to find out about our ancestors?

Answer 19

We study the remains that accompany hominid bones.
By looking at the bones and stone tools (often found with or instead of the bones), this can help us to reconstruct how our ancestors behaved, what they ate and how they might have lived

Question 20

What is directional selection? (What does it do?)

Answer 20

Altering a species’ phenotype. It’s not evolution, just getting rid of characteristics that don’t work. Acting against one extreme in a range of phenotypes making one become rare and an alternative one become more common

Question 21

What is stabilising selection? (What does it do?)

Answer 21

It acts against both extremes. The variation of the mode is reduced. It doesn’t lead to evolution. After selection, the mode is in the same position but the range has shortened. E.g. Child birth weight - too big won’t fit through birth canal, too small is underdeveloped. Fewer children are born too big or too small than they were previously as more are a normal weight.

Question 22

What is disruptive selection? (What does it do?)

Answer 22

Goes/selects against the average. Does lead to evolution. If you keep selecting against the mean, two new species would evolve. E.g. Grey rabbits are the original population, people mate black rabbits together and white rabbits together. As they differ more they recognise each other less and so mate with ones like them more and more before you get a defining split.

Question 23

What is speciation? What does it rely on?

Answer 23

The formation of a new species from an existing one.
It relies on strategies to reproductively isolate organisms and enough generations to render them unable to produce viable offspring.

Question 24

What is Allopatric Speciation?

Answer 24

When physical barriers like mountains or islands separate populations and they each adapt to their environments.

Question 25

What is Sympatric Speciation?

Answer 25

The speciation of organisms within the same habitat. Could be due to organisms going under biological changes, preferring different food species or different mates.

Question 26

What is Artificial Selection? Does it have another name?

Answer 26

The gradual improvement of animal and plant characteristics over time, for man’s benefit. We try to get eugenics - perfect genes
E.g. dogs were wolves, now cute or cuddly or big or small etc.
Sometimes called Selective Breeding

Question 27

Give a negative about Artificial Selection

Answer 27

We can lose genes to get monoculture where everything becomes the same. Some genes that are bad right now might be good in the future or vice versa.

Question 28

Give examples of higher yields as a result of Artificial Selection

Answer 28

Producing more milk (from cows etc.)
Producing more meat (from cows, pigs, sheep etc.)
Producing more fruit (from trees etc.)

Question 29

What do we use to ‘cut’ DNA?

Answer 29

Restriction Endonucleases - cutting enzymes that attack from within the strand

Question 30

What are plasmids?

Answer 30

Circles of DNA in bacteria separate from the main chromosome.
cDNA

Question 31

How do bacteria share plasmids?

Answer 31

They line up next to each other, compare their plasmids and then stick their pilus into the other and grabs it.

Question 32

Why are plasmids useful to genetic engineering?

Answer 32

We can get bacteria to produce things like insulin and spider silk. It is better for cost and religious reasons and also saves problem with mutations. Muslims and Jews don’t eat pig which is how insulin can also be produced. Bacteria is also simple and easy to GE so it is cheaper.

Question 33

What is a histone?

Answer 33

A group of basic proteins found in a chromatin

Question 34

What could a species be described as?

Answer 34

The first name of the organism, the genus is your surname and the species is your first name, identifies who you are in that genus

Question 35

What is a binomial name?

Answer 35

Universal organisms names which consist of Latin names. The genus comes first and then the species, such as humans are ‘homo sapiens’ where we are the species ‘sapiens’ in the genus ‘homo’. So relatives humans evolved from begin in homo as they had a similar genus/set of phenotypes