Evolution- Term 3

Question 1

What are Mutations?

Answer 1

Mutations are changes in DNA and chromosomes that lead to variation

Question 2

What are Mutagens?

Answer 2

They are something that can cause mutation.

Question 3

What are some Physical mutations?

Answer 3

Radiation, X-rays.

Question 4

What are chemical mutations?

Answer 4

Cigarettes, grilled meat.

Question 5

What are some biological mutations?

Answer 5

Viruses (HPV), Bacteria

Question 6

What are somatic mutations?

Answer 6

They are mutations which only affect the individual (Like mutations through UV exposure) as they are not inheritable. These occur on the body cells.

Question 7

What are Germline mutations?

Answer 7

These are heritable mutations which can get passed onto the offspring (mutations which cause cystic fibrosis). These occur in the sperm and egg.

Question 8

process by which populations of organisms…why?

What is evolution and how does it work?

Answer 8

Evolution is the process by which populations of organisms change over generations. The Species’ environment “selects” the most favorable characteristics for it to survive and the characteristics are heritable- inherited from previous generations.

Question 9

What is Biodiversity?

Answer 9

It refers to all the variety of life that exists on earth

Question 10

What is a species?

Answer 10

A group of similar individuals that breed to produce fertile offspring under natural conditions.

Question 11

Species is the smallest unit of….

Answer 11

Biological classification

Question 12

What does evolution imply about first forms of life and its drive?

Answer 12

The first life forms were simple and the number of species has now increased. these new species arise from common ancestors. Evolution is driven by outside forces and not an organism’s drive to change.

Question 13

What is an example of natural selection using giraffes

Answer 13

In a population of giraffes there are some with longer necks and some with shorter necks. Those with longer necks have a higher advantage as they can reach taller trees or branches to eat.

Question 14

What are the giraffes called if they have longer necks?

Answer 14

These giraffes are reffered to as being ‘fit’ as they are able to eat more and be stronger then giraffes with shorter necks

Question 15

What are giraffes called if they have shorter necks?

Answer 15

These giraffes are called weaker as they have limited access to food (resources)

Question 16

What giraffes would have a better chance of survival and why? What this result to?

Answer 16

Giraffes with longer necks are better adapted to their environment, and hence have a better chance of surviving. As a result, they can reproduce and pass on their advantageous genes to their offspring.

Question 17

The organisms ability to….. measure of…..

What does Fitness refer to?

Answer 17

Fitness refers to an organism’s ability to survive, reproduce and pass on it’s genes to the next generation. It is a measure of how well-suited an organism is to it’s environment and how effectively it can contribute to the gene pool of future generations.

Question 18

process by which…

What is Natural selection?

Answer 18

Natural selection is the process by which an environmental factor acts on a population, resulting in some organisms having a greater chance of survival than others.

Question 19

What are selective pressures?

Answer 19

Selective pressures are environmental factors that influence the survival and reproductive success of organisms within a population.

Question 20

What can selective pressures lead to overtime and what can that cause?

Answer 20

They can lead to natural selection, causing advantageous traits to become more common in a population over generations.

Question 21

What are Biotic factors?

Answer 21

Biotic factors are living environmental factors.

Question 22

What are some examples of Biotic factors

Answer 22

• Competition
• Resource availability
• Predation
• Disease
• Human impacts

Question 23

What are Abiotic factors?

Answer 23

Abiotic factors are non-living environmental factors.

Question 24

What are some examples of abiotic factors?

Answer 24

• Temperature
• Salinity
• Light
• Humidity
• Availability of nutrients
• Physical barriers

Question 25

What are Darwin's 5 principles of Natural selection.

Answer 25

1. More offspring are produced then can survive due to resource availability. 2. Population have variations 3. Some variations are both favorable and heritable 4. Those that survive have favorable traits ad will reproduce. 5. A population will change over time.

Question 26

Define the Theory of Evolution

Answer 26

Darwin proposed that species can change over time, that new species come from pre-existing species, and that all species share a common ancestor.

Question 27

Why do mice evolve to have varying coat colors base on the concept of natural selection.

Answer 27

There are an equal number of dark-brown owls and light-brown mice. In areas where the ground is dark, owls would see light-brown mice easier and catch more light-brown mice than dark-brown mice. As a result, dark-brown mice would have an increased chance to survive and breed. With the next generation having more dark-brown mice due to them being ‘naturally selected’ by the owls. Hence, natural selection refers to the selection and passing of desirable traits due to environmental factors.

Question 28

How does independent assortment contribute to new genes and mutations being created?

Answer 28

Independent assortment contributes to new genes and mutations being created due to the variation in the genes themselves and the almost endless combinations each of these genes can combine with.

Question 29

Why is genetic variation crucial?

Answer 29

It allows different genes from the species to be passed down (as they are inherited by future generations)

Question 30

What does the variety of genes allow?

Answer 30

A species to survive when a change occurs in their environment.

Question 31

What is another way of describing natural selection (genetic makeup)?

Answer 31

The change in genetic makeup (genotype) of a species over many generations due to environmental selection of a particular characteristic phenotype.

Question 32

How do the peppered moths show an example of natural selection?

Answer 32

Natural selection is the process by which environmental factors act on an organism, leading the species to mutate in order to have characteristics which are advantageous in this environment. The peppered moths are a great example of this as during the industrial revolution, where everything was covered in smog and blackness, including their habitat, they were eaten very often. This is because their white and black speckled body was very obvious to see. There was a natural mutation though where the bodies of these moths were almost fully black. These moths survived and therefore reproduced as they were not that obvious to spot out. Soon these black moths outnumbered the lighter moths. When the sooty-ness stopped, this cycle reversed.

Question 33

How do mosquitoes show an example of natural selection?

Answer 33

DDT was originally the cure to malaria caused by mosquitoes, however mosquitoes that had the genotype for resistance to DDT where able to survive and hence, reproduce more.

Question 34

What does the Mosquitos and DDT problem highlight when it comes to pest control?

Answer 34

It is important to use a variety of pest control methods to reduce the likelihood of developing a resistant population of pests.

Question 35

How does Bacteria show an example of natural selection?

Answer 35

A common method of destroying bacteria is through antibiotics, however (similar to the mosquitoes), bacteria can become resistant to antibiotics. Overtime, some did in fact become resistant because of natural selection. This was a huge problem as bacteria can reproduce rapidly- often creating a new generation within 20 minutes.

Question 36

What is Artificial selection?

Answer 36

It is where breeders select favorable characteristics and breed animals or plants with those characteristics.

Question 37

How does artificial selection occur? Process

Answer 37

It happens across generations 1. Breeders select animals with desirable characteristics and breed them together 2. Animals with features determined to be undesirable are not bred 3. eventually, unwanted characteristics will be removed from the population, leaving for desirable traits.

Question 38

What is sexual selection?

Answer 38

Sexual selection is the process by which individuals compete for access to mates and fertilization opportunities

Question 39

What traits are more favorable for reproduction than others?

Answer 39

- Size/ strength - Bright Plumage - Large antler's/ horns - vocalisations

Question 40

What happens if a particular trait is considered favorable to a mate (sexual selection)

Answer 40

Then the organism with this trait is more likely to produce and hence pass this trait onto their offspring- as a result these preferred traits become more common in the population over time. Those that cannot find a mate as they have undesirable traits have less chance to mate, therefore letting their traits die out with them.

Question 41

What is speciation?

Answer 41

Speciation is the process of one species splitting into two or more new species. This leads to high levels of biodiversity.

Question 42

What are the steps of speciation?

Answer 42

Variation- Isolation- Selection

Question 43

What is variation (in relation to speciation)

Answer 43

There must be variation within the species gene pool-variation mutations

Question 44

What is Isolation (In relationship to speciation)

Answer 44

Different groups of the same species are prevented from breeding with one another- a geographical barrier is a common way animals become isolated. This prevents the gene flow throughout the population. - Mutations from one population cannot be passed into the other population due to isolation.

Question 45

What is Selection (In relationship to speciation)

Answer 45

Natural selection acts on each population but there may be differences that influence the two population such as: - Predation, seasons, chemical barriers, sterility, courtship behavior.

Question 46

Speciation relating to the Galapagos finches- What did Dawrin find with reference to variation amongst the finches?

Answer 46

There was variation within the finch species which produced different beak shapes and sizes. Natural selection acted

Question 47

Speciation relating to the Galapagos finches- What did Dawrin find with reference to isolation amongst the finches?

Answer 47

All of these finches were separated by a geographical barrier (the ocean between them).

Question 48

Speciation relating to the Galapagos finches- What did Dawrin find with reference to selection amongst the finches?

Answer 48

Natural selection acted upon each population in a different way due to the different food sources on each island.

Question 49

Why can different species not interbreed?

Answer 49

Because they usually cannot interbreed to produce fertile offspring. This is because of genetic incompatibility- mainly due to differences in their DNA, chromosome structure or number.

Question 50

What is a Hybrid?

Answer 50

When two very similar species interbreed, creating offspring known as hybrids. Many of these offspring have health problems and are infertile, only some being fertile.

Question 51

What are the Ethic problems of creating a hybrid species?

Answer 51

Invasive species and welfare of the hybrid animals.

Question 52

Expand of the ethics of invasive species

Answer 52

Hybrid creations can sometimes result in the creation of invasive species that can disrupt ecosystems and threaten native biodiversity.

Question 53

Expand of the ethics of the welfare of hybrid animals.

Answer 53

Breeding hybrid animals should prioritise their health and wellbeing. It is crucial to ensure that the hybrids are not subject to unnecessary suffering pain or distress during the breeding process or throughout their lives.

Question 54

What are the five major areas that provide significant evidence for the theory of evolution.

Answer 54

1. The fossil record 2. Comparative anatomy 3. Genetics and biochemistry 4. Geographic distribution of species 5. Embryology

Question 55

How do fossils provide evidence of evolution?

Answer 55

1. They document the course of life through time 2. They illustrate simple organisms becoming more and more complex through speciation.

Question 56

Mutations from genotypes don't occur in every generation. True of false

Answer 56

False. Mutations from genotypes do occur in every generation.

Question 57

How do fossils illustrate simple organisms becoming more and more complex through speciation.

Answer 57

Fossils of the simplest organism are found in the oldest rocks, and fossils of more complex organisms in the newest rocks. They show the transitional forms of a species- where an organism shares characteristics of two species. - They represent a generation of organisms who are in the process of evolving from one species to another.

Question 58

How does the fossil of a horse show that?

Answer 58

There are 3 key changes that have been observed throughout the fossil record 1. the Body size has increased 2. The legs have become larger 3. The number of toes have decreased.

Question 59

What is comparative anatomy and how does it provide evidence of evolution?

Answer 59

It is the science of comparing the physical strictures of a species with others. Darwin proposed that the pentadactyl limb of a distant ancestor was modified by natural selection to form different limbs of all currently living four footed land animals (tetrapods)

Question 60

What are homologous structures (Comparative anatomy)

Answer 60

Structures that are similar in related organisms, because they were inherited from a common ancestor. Organisms that belong to distantly related groups can share similar structures have the same basic structure but may perform a different function.

Question 61

What does structures that are similair in related organisms suggest?

Answer 61

That we all evolved from a common ancestor. Their functions are only different becuase of natural selection- our structures have evolved differently due to our exposure to different selective pressures.

Question 62

What are Analogous structures (Comparative Anatomy)

Answer 62

These are characteristics that do look similar but do not share a common ancestor. For example, sharks and dolphins both have analogous body types however they do not share a common ancestor. This is becuase they were both exposed to similair environmental pressures. They have evolved to have this characteristic independently.

Question 63

How do genetics and biochemistry show evidence of evolution?

Answer 63

Organisms that have similar anatomy have similar genes. Essentially their DNA is similar, indicating both species evolved from a common ancestor.

Question 64

What is a common protein found in all living organisms?

Answer 64

Cytochrome C

Question 65

What are Hox genes and what do they do?

Answer 65

Hox genes specify the location and type of structures that an organism should grow at the embryonic stage of life, like building instructions from your body.

Question 66

Are the structures built by Hox genes simialir or different in each animals?

Answer 66

They are different as their location within the Animal's DNA are different, and mutations have occurred overtime to change the function of these structures they create. The presence of these genes in all animals is evidence we come form one ancestor.

Question 67

How does Geographic distribution show evidence for evolution

Answer 67

Darwin and wallace observed that isolated places have many more unique species and without gene flow from other populations, the species become more divergent from other members of their species due to natural selection.

Question 68

What animal is a great example of geographic distribution

Answer 68

The Galapagos island and Darwin's finches

Question 69

What is Embryology?

Answer 69

Embryology refers to the study of the development, structure and function of embryos.