Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > Evolution > Flashcards

Evolution Flashcards

(76 cards)

Start Studying
1
Q

Variation

A

Differences in characteristics of individuals in a population

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

3 causes of variation in any population

A

-Inheriting different alleles from parents like hair colour
-Environment changes like colours of flower due to soil
-Combo of environment + genetics like height

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

What causes the genetic variation in species?

A

Mutations or random changes in DNA

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

Types of mutations

A

-No effect on the phenotype
-Influence the phenotype under certain circumstances
-Completely determine the phenotype (rarely)

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

How do mutations effect a population?

A

If the environment changes
A mutation could help them survive or resistant to change
Thus the surviving organisms will have a different phenotype
And will be inherited by all other organisms
Which is the baseline for evolution

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

How have different species come to be on earth?

A

All have evolved over very long period of time from simple single cells
Through evolution by natural selection

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

Stages of natural selection aka evolution

A

Species have a lot of genetic variation for diff phenotypes
If the environment changes, those with alleles to adapt to this change more likely to survive
Thus more likely to reproduce
And their offspring could inherit this allele then reproduce
Thus over time the whole population will have this phenotype

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

Evolution

A

The change in inherited characteristics of a population over time through natural selection

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

How does an animal differentiate into 2 different species?

A

If 2 populations of species become so different in phenotype over a period of time
Due to evolution
That they can no longer interbreed and produce a fertile offspring
= 2 separate species

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

Selective breeding

A

When humans decide which animals/ plants with a specific phenotype to breed in order to get an offspring with a desired phenotype
Pretty much speeding up the process of evolution but so they’re more useful to us

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

Examples of selective breeding

A

Dogs = more gentle nature
Crops = disease resistance
Cattle = more milk/ meat
Plants = large flowers

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

Stages of selective breeding (cows for meat)

A

Take mixed population of cows and select largest male + female
Breed them
Sexual reproduction = variation so some offsprings don’t have desired characteristic
So select the largest male and female offspring from that
Breed them
Repeat for many generations until all offsprings are large

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

Big problem with selective breeding

A

Breeding closely related animals/plants = inbreeding
Which cause being prone to disease or inherited defects

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

Genetic engineering

A

When a gene from one organism with a specific characteristic
Is taken from an organism
And transferred to another when in development so it has that characteristic

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

Using genetic engineering for type 1 diabetes

A

Putting the insulin producing gene in bacteria from a human
Then purified
So it produces insulin
Thus can help treat type 1 diabetes

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

Genetically modified

A

When you transfer a human gene to an organism to make it carry out a specific function/ have a specific characteristic

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

Why would we genetically modify crops?

A

Produce a greater yield
Resistant to disease/ insects
Produce bigger fruits
Resistant to herbicides so farmers can kill weeds but not harm the crops

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

Disadvantages of genetically modified crops?

A

Possibly harm insects
Or wild flowers
Health effects if humans eat it needs more research

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

Gene therapy

A

Using genetic modification to cure inherited disorders in humans

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

Disadvantages of gene therapy

A

We don’t know long term effects
Don’t know if it has effects on other genes

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

Steps of genetic engineering

A

Identify gene we want to transfer (from animal/human/plant)
Use enzymes to isolate it
Transfer gene into a circle of dna called plasmid from bacteria, or into a virus
Desired gene is transferred into target organism

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

Vector

A

The plasmid or virus that transfers the DNA from one organism to another

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

In genetic engineering Why do we transfer gene at an early stage in the target organisms development?

A

Make sure all cells receive the transferred gene
So the organism develops with this characteristic

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

Clone

A

Organism genetically identical to its parent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Advantages of cloning plants
Because it’s genetically identical to parent we know what it’s characteristics will be
26
Cloning plants using cuttings
Take small cutting of plant Dip the end in rooting powder Thus the plant develops roots And is genetically identical
27
What method to get hundreds of clones of a plant?
Tissue culture
28
Tissue culture stages
Take parent plant Divide into many small pieces Containing small number of cells Incubate with plant hormones So the plant is stimulated to grow and develop fully grown clones
29
Conditions for tissue culture
Sterile So we don’t have any microorganisms like bacteria or fungi
30
Adv of tissue culture
Thousands of genetically identical plants quick and cheap (commercially) We can be certain of characteristics Preserves rare species
31
Who began classifying species?
Carl Linnaeus
32
Classification system Linnaeus developed
2 kingdoms: plant and animal Each then divided into smaller categories
33
What were the smaller categories Linnaeus developed?
Kingdom Phylum Class Order Family Genus Species
34
How to remember smaller categories Linnaeus came up with
Kingdom = King Phylum = Philip Class = Came Order = Over Family = For Genus = Good Species = Soup
35
Binomial name system
Species name is: Genus + species Eg homo sapien
36
What is Linnaeus system based on?
Characteristics we can physically see
37
Why did Linnaeus system change
Advances in science so we don’t have to base it on what we see We can use tech to Analyse dna
38
What classification system is used now?
Three domains
39
Who came up with three domain system
Carl woese
40
What’s in the 3 domain system?
Archae (primitive bacteria) in hot springs True bacteria (in our bodies) Eukaryota (animal, plants, fungi, protists, amoeba)
41
How can we tell how closely related species are?
Evolutionary tree The length of time goes up the scale at the side
42
How to make an evolutionary tree?
Use classification data on living ones like dna But if it’s extinct we use fossils
43
Problem with evolutionary tree
Extinct creatures can only be judged on fossils But records of fossils for some are incomplete
44
How do evolutionary trees work?
Where it crosses = common ancestor
45
Fossils
Remains of organisms from millions of years ago in rocks
46
How can fossils form?
If conditions for organism to decay aren’t there thus it doesn’t ie too cold, no oxygen or water If the organism decays but is replaced by minerals By traces of organisms like footprints
47
Problem with fossils
Most organisms didn’t have skeleton (soft body) And didn’t form fossils And the ones that did were destroyed due to changes in earths crust
48
What do fossils show
Huge number of species that have been extinct
49
Ways of cloning animals
Embryo transplants Adult cell cloning
50
Embryo transplant stages
Sperm and egg cell from target mammal with desired characteristics Produces fertilised egg Develop into early stage embryo Use glass rod to split in 2 Transplant this into 2 host mothers to give birth Therefore have 2 identical offspring = clones
51
Why must we separate an early stage embryo into multiple embryos during embryo cloning?
So the cells don’t specialise into specialised cells before they can be split
52
Problem with embryo transplants
Because it undergoes fertilisation in sexual reproduction, we can’t be certain it has desired characteristics as it’s varied
53
How can we overcome the problem with embryo transplants?
Use adult cell cloning instead
54
Benefits of adult cell cloning
Cloning from an adult = we know what characteristics it will have
55
Stages of adult cell cloning
Take cell from target animal Remove nucleus Take unfertilised egg cell from same species Take the nucleus out of this egg cell and throw it away So we insert nucleus from original target animal cell So now it only contains genetic info from target animal Give it an electric shock so it divides = embryo As the embryo develops, put in host mother to continue development
56
Why does the host mother and clone look different in adult cell cloning?
Because we are NOT cloning the host mother!!!! She is acting as a surrogate to give birth to it and provide it with what it needs We are cloning a different animal
57
Evolution by natural selection (triple science)
In a species there is lots of genetic variation for characteristic Ones with characteristics most suited to environment can breed most successfully So the useful characteristic could be passed to next generation
58
On the origin of species
Darwin’s theories of evolution published book
59
Origin of species book reception at the time
Very controversial Only became gradually accepted
60
Why was Darwin’s work not accepted at first?
Strong belief god made everything Some felt he did not have enough evidence Not understanding of how things are inherited
61
Jean baptise Lamarck theory
If characteristic is regularly used it develops more thus passes to its offspring
62
Problem with Lamarcks theory
Changes due to environment are not passed onto offspring So it’s incorrect
63
Wallace’s theory
Same evolution by natural selection theory as Darwin Came up with it separately at the same time So they jointly published their studies
64
Speciation
How new species form from different animals
65
What did Wallace notice when studying speciation?
Closely related species are separated by geographical barriers eg a river
66
How do new species form?
If a geographical barrier separates a population The population could once interbreed and spread mutations But now they can’t breed And natural selection favours different alleles on either side that will change the population Thus 2 they can’t spread this mutation and will develop into separate species
67
How do we know when we have developed a different Species?
Can no longer interbreed to produce a fertile offspring
68
Who came up with many of the discoveries of genetics?
Gregor Mendel
69
How did Mendel carry out experiments?
Looked at shape of the pea pods and its flowers
70
What did Mendel’s experiments show him?
Genes aren’t blended together but we get how we look from inherited units These don’t change as we pass them down These could be masked and reappear with later generations
71
How was mendel’s work accepted?
Scientists studied cell division and saw chromosomes act in a similar way to what Mendel said
72
What organisms evolves extremely quickly?
Bacteria under ideal conditions
73
Examples of antibacterial resistant
MRSA
74
What causes bacteria resistance to antibiotics?
Mutation causes one to be resistance to antibiotics Antibiotic kills all bacteria except the resistant one So it begins to reproduce with no competition = resistant strain rises and spreads
75
How to reduce bacteria resistance?
Not prescribe antibiotics inappropriately Patients complete course of antibiotics so none can mutate Restrict use in farming
76
Problem with creating new antibiotics
Too slow and expensive Once developed it can’t keep with the new strains of resistant bacteria

Biology (55 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions