Week 8 Flashcards

(92 cards)

1
Q

What evidence supports the theory that dinosaurs were the ancestors of birds?

A

Fossilised feathers were found on a dinosaur called Anchiornis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do fossils of fish and amphibians of the Devonian period have in common?

A

Bones and limbs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Do these bones of fish and amphibians stay the same over time?

A

No. There is a gradual change in the structure of the whole limb over time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define evolution?

A

A genetic change in the characteristics of a species over many generations, resulting in the formation of a new species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define generation?

A

The time between the birth of an individual and when that individual produces their own offspring.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The fossil of which animal is a good example of changes over generations?

A

The horse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How many different genera of the horse have been found and dated?

A

17

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name the four changes in the horse and the height of each one?

A

Hyracotherium-0.4 m
Mesohippus-0.6 m
Merychippus-1 m
Equus-1.6 m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How are organisms classified?

A

On the basis of their structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What did biologists studying evolution from 150 years ago think about structure.

A

Organisms that were very similar in structure must be related

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe natural selection?

A

An environmental factor acts on a population and some organisms have more offspring that others

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a selective agent?

A

The environmental factor that acts on a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define biotic factor?

A

A living thing

Eg: predation, bacterial infection, competition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define physical factor?

A

A more environmentally based factor

Eg: susceptibility to fire, soil nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe how selective agents that kill individuals act?

A

By preying on the poorly adapted and less fit individuals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe how sexual selection works?

A

Organisms are selected to breed based on what they look like or their sexual appeal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe how selective agents change populations?

A

Favoured individuals pass on their genes and features to the next generations.
Populations change and they become better suited to their environments.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is meant by variation?

A

Natural selections in the population caused by differences in genes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How is natural selection related to genetics?

A

Natural selection is the change in the proportion of a genotype of a species over many generations due to the environmental selection of a phenotype.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What did Charles Darwin propose?

A

Natural selection could result in the formation of new species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does the theory of evolution propose?

A

Similar species must be closely related to each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does similarity between species indicate?

A

They had a common ancestor at some time in the past.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which creature did Darwin study to come up with his theory?

A

Finches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which part of the creature caused Darwin to believe that finches had a common ancestor?

A

Their beaks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What did he believe caused what did Darwin believe caused the difference in the finch's beaks?
The different beaks had been selected for the different food sources found on different islands
26
Can you determine if two organisms are from the same species from their anatomy?
No, it's impossible
27
What is the test for a species?
To see if two organisms could interbreed to produce fertile offspring under natural conditions.
28
Give an example of an interbred species?
The mule, produced by crossing a horse and a donkey.
29
Which method is mostly used by biologists today to see if organisms are the same species?
They study DNA and also identify the similarities in the amino acid and arrangement in the proteins they make.
30
Define specification?
The process by which one species splits into two or more separate species
31
Define biodiversity?
The number and range of species that exist, either on the whole Earth or any of Earth's ecosystems
32
How is specification related to biodiversity?
Specification has resulted in the high level of biodiversity on the Earth
33
List the three basic steps of specification?
1) Variation 2) Isolation 3) Selection
34
Which group of organisms were the ancestors of birds?
Dinosaurs (the theropods)
35
Under what condition is natural selection able to act?
There must be variation in the population or specification cannot occur
36
Define isolation?
Where different groups of the breeding population are prevented by some mechanism from interbreeding
37
What does isolation prevent?
Gene flow throughout the population, stopping any differences in one population from reaching the other population
38
List some ways that isolation occurs?
By a geographical or climate barrier
39
After isolation, what does natural selection affect?
The genotype. It also causes changes that prevent the groups breeding
40
List some changes that can occur that will prevent individuals of different species breeding
Courtship behaviour-animals may develop different breeding songs, displays and rituals Breeding seasons-animals may breed at a different time of the year Sterility-animals may breed but the offspring are sterile Chemical barriers-sperm may be killed by the chemistry of the female
41
Is isolation only caused by geographical barriers?
No, it is also caused by climate change
42
Once a change in genotype has occurred, could individuals with different genotypes breed?
No, the changes prevent the groups breeding
43
How are early fossils different to later fossils?
Early fossils are of fairly simple organisms and later ones are increasing complex.
44
Explain why early fossils are of simple organisms and later ones are of complex organisms?
New alleles and genes develop from existing genes by mutation
45
List three species that have become extinct?
Dinosaurs, diprotodons, marsupial lions
46
Give two examples of transition forms.
Lobe-finned fish: part fish, part amphibian | Archaeopteryx: dinosaurs that had feathers
47
Define comparative anatomy?
It compares the structures of organisms of both living species and fossils
48
Give an example of a homologous structure that provides evidence of evolution?
Pentadactyl limbs provide evidence from a single vertebrate ancestor
49
How are all living cells the same?
They all have the same basic structure basic structure and use the same genetic code
50
How are proteins produced?
From genes that all come from the same set of amino acids
51
What is the relationship between genes of different organisms and the similarity of different organisms.
Organisms that seem to be fairly similar, on the basis of comparative anatomy, show more genes in common than organisms that are less alike.
52
Besides DNA, what else can be used to test for the similarity of species?
Protein amino acid sequence
53
How it protein amino acid used to determine the similarity of different species.
Comparing how many of the amino acids are found in the same position as the protein chain can provide some idea of how closely related two species are.
54
Define species distribution?
A map of all the places where a species occurs
55
Where do unique species tend to occur?
On isolated islands
56
What part did fossils play in giving evidence for continental drift?
It convinced scientists that continents moved because of the distribution of fossils in particular species.
57
Would Australia count as an isolated island?
Yes, evidence from plate tectonics shows Australia has been isolated from all the other landmasses from about 40 million years ago
58
Define embryology?
The study of the development, structure and function of embryos.
59
What do comparisons of vertebrate embryos show?
Striking similarities in the early stages of their development
60
How does the development of branchial arches differ between species?
They develop into something different in each species
61
What did fish's branchial arches evolve into?
Gills
62
What did reptile's branchial arches evolve into?
Their lower jaw
63
What did human's branchial arches evolve into?
Their ear bones
64
What did chick's branchial arches evolve into?
Their parathyroid gland
65
Summarise the evidence for evolution?
``` Fossils Comparative anatomy DNA Protein structure Distribution of species Embryology ```
66
How do fossils provide evidence for evolution?
There is an increasing complexity in species, changes over geological time in a linage and transitional forms.
67
How does comparative anatomy provide evidence for evolution?
Homologous structures can be identified at many different levels of classification, such as the limb bones in classes of vertebrates.
68
How does DNA provide evidence for evolution?
Species that have similar anatomy have been shown to have many more common genes
69
How does protein structure provide evidence for evolution?
Closely related species have more similarities in amino acid sequences in particular proteins
70
How does a high distribution of species provide evidence for evolution?
Isolated islands have unusually high proportions of unique species
71
How does embryology provide evidence for evolution?
Embryos with similar anatomy share some of the same genes for development of the embryo. These same genes can exert different effects in different species.
72
What was the premise of the view: organisms that were very similar in structure must be related?
Knowledge that organisms seemed to inherit their characteristics from their parents.
73
Did modern genetics confirm that organisms seemed to inherit their characteristics from their parents?
Yes, genetics showed that species with the same basic structure have many genes the same or similar in their effect. Species that have the same genes must have had the same ancestor at the some stage.
74
By which process are the genes passed on from one generation to the other?
Meiosis
75
Define homologous structure?
Characteristics that have the same basic structure but not necessarily the same structures in related species
76
Give three example of homologous structures?
Human hand Whale flipper Bat wing
77
Give three examples of structures that are not homologous?
Cats paw Insect foot Horse hoof
78
What do scientists study about genes?
Chemical structures and function
79
The more alike two organisms are ....
The more genes they share
80
As you move from higher levels of classification to lower levels ....
The more alike those genes become
81
Do homologous structures always have the same function in organisms that share it.
No, humans, bats and whales have five digits at the end of limbs, humans grip and traction, whales propel, bats fly,
82
Define analogous structures?
Structures that looks similar in genetically different organisms. Eg: sharks and dolphins-similar body shaped and fins
83
Does artificial selection occur in the wild?
No, humans choose to breed particular organisms with desirable features
84
Define artificial selection?
Process where breeders cross (mate) the selected parents and then allow offspring to reach maturity before selecting which will be bread.
85
Are blue budgies natural?
No, wild budgies are green and yellow.
86
Are blue budgies mutants?
Yes, the variations in the wild budgie population were all originally results of mutants
87
Does artificial selection happen fast or slow?
It happens over generations?
88
Give five examples of breeds of dogs likely produced by artificial selection
Collie, pug, German shepherd, basset hound, Alaskan malemute
89
Give five examples of cats likely produced by artificial selection?
Persian, Siamese, Burmese, rag doll, munchkin
90
Two main methods of selective breeding?
Cross breeding | Interbreeding
91
Define cross breeding?
Combining a desirable feature of one individual with a desired level feature of another
92
Define interbreeding?
Related individuals are allowed to mate