Evolution

Question 1

Gene pool

Answer 1

The sum total of genetic information present in a population

Question 2

Selective pressure

Answer 2

Environmental conditions that favour certain individuals

Question 3

Selective advantage

Answer 3

Organisms that have better phenotype to survive will have more likely survive and pass them onto the next generation

Question 4

Is it easier for natrual selection to get rid of a dominate or recessive trait

Answer 4

It’s easier to get rid of a dominant trait due to heterozygous Bb have the same selective advantage as BB and when having offspring there is still always a chance for the recessive trait to occur.

Question 5

What is gene flow

Answer 5

Also known as migration
Changes due to migration can occur very quickly
Is directional

Question 6

What’s genetic drift

Answer 6

Is a pattern of random change in allele frequency from one generation to the next
the direction of change is UNPREDICTABLE.
Unlike natrual selection it does not favour one allele over another
Mainly occurs in small populations

Question 7

What is genetic bottle neck

Answer 7

When the size of population is drastically reduced from a bush fire, flood, new disease etc.
The few survivors that reproduce to give the next generation may be an underrepresented sample of the original gene pool

Question 8

What’s the found effect

Answer 8

When a small underpresentative or nonrandom sample of the population leaves to colonies a new region.
The first organisms of the population to start a new colonie are called founders

Question 9

What’s a mutation

Answer 9

New alleles occurring due to mistake in DNA

Question 10

Whats point mutation

Answer 10

Affects a single base in DNA
by substitution
Commonly affect structural genes

Question 11

What’s a frameshift mutation

Answer 11

A three nucleotide (codon) insertion or deletion cause the genes message it encodes to no longer make sense

Question 12

What’s a block mutation

Answer 12

Chromosomal change affecting large segments of a chromosome
Either:
Deletion of part of a chromosome
Duplication or gain of part of a chromosome
Translocation or reciprocal exchange between non homologous chromosomes
Inversions when a segment of a chromosome rotates through 180 degrees

Question 13

What’s aneuploidy

Answer 13

The presence of an abnormal number of chromosomes eg a human cell contain 45 or 47 chromosomes

Question 14

What’s polyploidy

Answer 14

When a cell contains more than two sets of chromosomes

Question 15

Define natural selection

Answer 15

A process by which new heritable traits of organisms better adapted to their environment tend to survive and produce more offspring

Question 16

What’s the steps of natural selection

Answer 16

• There is variation between individuals
• Organisms with favoured phenotype will have an improved chance of survival and reproducing.
• individuals who survive and reproduce increase the chances of passing those genes on to the next generation
• favoured genes will increase in frequency within the population over time
• over long period of time the characteristics of the favourable gene will be the most noticeable within the population

Question 17

Why can’t organisms produced asexually not undergo natural selection

Answer 17

They do not have variation between individuals

Question 18

Living factors of selective pressures

Answer 18

Predators , competing for food, water, space, mates, parasites

Question 19

Non living facfors of selective pressures

Answer 19

Changes to temperature, pollutants, availability of water, minerals, light and natural disasters

Question 20

Define biological species

Answer 20

A group of interbreeding individuals, they are often composed of different populations that are quiet distinct these are known as subspecies.

Question 21

What does speciation mean

Answer 21

Refers to the process by which new species are formed
It occurs when gene flow has ceased between populations where it previously exists
Is brought about by development of reproductive isolating mechanisms which maintain the integrity of the new gene pool

Question 22

What’s the two types of speciation

Answer 22

Splitting and budding

Question 23

What’s splitting speciation

Answer 23

A species could split fairly equalling into two populations that envolve differently until they eventually become separate species

Photo

Question 24

What is budding speciation

Answer 24

A small part of species population could “bud off” from main part and evolve rapidly to form a new species while leaving most of the original species population unchanged

Photos

Question 25

What is allopathic speciation

Answer 25

Populations become geographically separated and become subjected to different selection pressures. They establish reproductive isolating mechanisms in isolation.

Question 26

Step 1 of allopathic speciation

Answer 26

Moving into new environment The population occupies new parts of the environment The population has a common gene pool that interbreed

Question 27

Step 2 of allopatric speciation

Answer 27

Geographical isolation Gradual formation of physical barriers may isolate parts of the population at the extremes of the species range The gene flow between the isolated populations is prevented and becomes rare

Question 28

Agents causing geographical isolation include

Answer 28

Continental drift, climate change and changes in sea level

Question 29

Step 3 of allopatric speciation

Answer 29

Formation of subspecies Isolated populations have different selection pressures that will favour the individual traits suited to each environment Natural selection occurs

Question 30

What's atage 4 of reproductive isolation

Answer 30

Each sub species develops reproductive isolating mechanisms | Even if geographical barriers are removed the species will no longer breed with each other

Question 31

What is artificial selective/ selective breeding

Answer 31

``` Involves breeding (selecting) from individuals with the most desirable phenotype. Selection imposed by humans is more intense and rapid then occurring in nature ```

Question 32

How does artificial/ selective breeding occur

Answer 32

Artificial insemination, embryo transfer,

Question 33

Does Loss of genetic variation matter

Answer 33

When a disease occurs if all the species are the same they will die out eg when the potato famine occurs one million Irish pease te died due to not having enough potatos to feed on. Variation is needed if the environmental conditions changes

Question 34

What are scientists doing to stop a disease in crops destroy everything

Answer 34

The keep seed banks and gene banks that seek to conserve diversity in plant species

Question 35

What are fossils

Answer 35

Any parts or impressions of an organism that may survive after death

Question 36

When do fossils form

Answer 36

Only under special conditions: Anything from water has more chance of forming a fossil Fossils form best when organisms are buried quickly as it slows the decay process

Question 37

What types of rocks are fossils most commonly found

Answer 37

Sedimentary rock

Question 38

What's a fossil rock profile

Answer 38

Layers of sedimentary rock arranged in the order they were laced down. The most recent layers are near the surface

Question 39

Define evolution

Answer 39

Permanent genetic change in a population of individuals over an extended period of time Does not refer to changes occurring to individuals over their own life time

Question 40

What's the two types of evolution and explain

Answer 40

Micro evolution- describes small scale changes which gene pools over generation Macro evolution- large scale changes in form as viewed in the fossil record involving whole groups of species.

Question 41

Index fossils

Answer 41

Fossils used to identify geological periods

Question 42

Transitional fossil

Answer 42

Fossils that are intermediate between ancestral and descendant species. They show evolutionary transition

Question 43

What's absolute dating

Answer 43

If a fossil can be accurately age then it is easier to form accurate time of life

Question 44

Radiometric/ isotopic dating

Answer 44

More accurate way of dating fossils. The method measures the amount of isotopes that are radioactive in either the fossil or rocks the fossil is found in

Question 45

What's radio carbonate dating

Answer 45

Used to identify the age of young fossils. Carbon is found in dead remains of organisms. Most of carbon is non radioactive carbon 12 while a small amount is in form of carbon 14 is radioactive. Carbon 14 breaks down into nitrogen 14 Carbon 12 will not break down By comparing the amount of carbon 14 with nitrogen 14 you can get a more accurate age

Question 46

The diagram for radio carbonate dating

Answer 46

Photos

Question 47

Homologous structures

Answer 47

Structure in different organisms that have a similarities present as a result common ancestory. Even though they may serve a different function as they have been adapted for a different purpose. Eg wing, arm, leg etc This provides evidence for divergent evolution

Question 48

Anologous structures

Answer 48

Have similarities between species but is not inherited from a common ancestor Structures that have the same function in different organisms may come from different origins Eg wings on birds and butterflies May indicate convergence evolution

Question 49

What is DNA hybridisation used for

Answer 49

One way to reconstruct the evolutionary history of species

Question 50

What is the process of DNA hybridisation

Answer 50

DNA from two different species is unzipped and recombined to form hybrid DNA Heat is used to separate the hybridised strands The amount of heat required to do this is a measure of how similar the DNA strands are (%bonding) More heat required displays that there are more bonds equalling DNA to be similar Less heat required for very different species

Question 51

Amino acid sequencing in evolution history

Answer 51

Closely related species have proteins with similar amino acid sequences The degree of similarity of these proteins is determind by the mutations that have occurred. The greater the time since common ancestry= more mutations

Question 52

What is divergent evolution

Answer 52

When closely related species become more dissimilar over time usually in response to different environmental conditions and selection pressures

Question 53

What's an example of divergent evolution

Answer 53

Galapagos island finches | Natural selection occurred resulting in different species of birds changing to suit the foods they eat on the islands

Question 54

What is convergent evolution

Answer 54

Occurs when similar features develop independently in organisms that are not clearly related but may live in similar environments. Eg a wolf ang tiger

Question 55

What's a mass extinction

Answer 55

A period in the geologic history of the earth during which an abnormally high number of species die out over a relatively short time frame

Question 56

What is mitrochondrial DNA

Answer 56

Another piece of evolutionary evidence MtDNA inherited from the mother only By comparing mtDNA in populations it is possible to trace the origin of mtDNA to a female ancestor in Eastern Africa called mitrochondrial eve

Question 57

Gene regulation and natrual selection

Answer 57

Two important genes in Darwin finches BMP4 a regulatory gene- this gene stimulates the production of material that makes beaks CAM-a gene that regulated calcium that makes the shape of the beak When BMP4 is turned on early the CAM gene is turned on late then a short break occurs

Question 58

What's the molecular clock do

Answer 58

Uses mutation rates in DNA to estimate the time two species split and evolve independent

Question 59

What does the molecular clock theory rely on

Answer 59

The Mutations are neutral, they do not affect phenotype | The mutations occur at a fairly regular Occassion

Question 60

What does each degree below 87 degrees represent in DNA hybridisation

Answer 60

The percentage of difference in the DNA

Question 61

What's the first group of organisms that show human features

Answer 61

Primate- advanced group of mammals that share common characteristics

Question 62

Characteristics of primates

Answer 62

Vision- large forward facing eyes with 3D vision Face- snout is reduced and sense of smell also Collarbone-ability to rotate the arm so it can extend behind the body Posture- upright and erect posture at times Hands-opposable thumb Reproduction- maternal instincts exist Social organisation- live in groups

Question 63

What's hominoids

Answer 63

Grouping of greater and lesser apes including gorillas, chimpanzee and humans

Question 64

What's a hominins

Answer 64

Modern human species and our extinct close relatives that could walk erect on their hind legs in a sustained fashion

Question 65

What happened to the foraminifera magnum over time

Answer 65

Moved further forward so the skull is balanced on the spine

Question 66

What's cultural evolution and examples

Answer 66

``` Changes in human societies over time where those changes are socially passed on and not genetically Eg domestic animals Burials and rituals Totems Paintings ```

Question 67

What's technology evolution

Answer 67

Development of technology that gives humans increased control over their environment. It has increased at an exponential rate. The rapid increase of tools is directly related to cultural evolution and increase in brain size

Question 68

Human evolution 5 significant developments over 5 million years

Answer 68

1. Hind limbs become longer so forelimbs no longer drag 2. Stance progressively became upright due to change in position of foramen magnum 3. The brain capacity increase=increase intelligence 4. The size of jaw decreased 5. Thumbs became fully opposable. Toes straighten and arc develops in feet

Question 69

What's the out of Africa model

Answer 69

Homo sapiens sapiens have common origin in Africa. Members from Africa migrated out. Supported by mitrochial DNA

Question 70

What's classified as a young fossil

Answer 70

40,000-50,000 years old

Question 71

What causes antibiotic resistance

Answer 71

Any mutation that provides an advantage under certain selection presses may spread quickly through bacteria population This has created the selective environment for increased frequency of antibiotic resistance genes in populations

Question 72

Relative dating vs absolute dating

Answer 72

Absolute dating is the exact age of a fossil eg Relative dating is the relation of age compared to rock layers around it eg the fossil position in the layer of rocks