Yr 10 Science - Biology

Question 1

What is evolution?

Answer 1

Evolution is a process of descent with modification. It is the gradual change of a species characteristics over the course of several generations. It happens when genes mutate and cause new characteristics that are passed down.

Question 2

What is the purpose of evolution?

Answer 2

Evolution enables an organism to adapt to its environment and help them to survive. The traits they gain through evolution are passed down genetically.

Question 3

What are the five basic steps of natural selection?

Answer 3

VISTA -
1. Variation, the gene pool allows for some variation within a species.
2. Inheritance, the traits encoded in DNA are passed on to offspring.
3. Selection, not all organisms that are born can survive. Organisms that have variations that better suit their environment are more likely to survive.
4. Time, organisms with better variables and traits are more likley to survive and reproduce. These traits are passed on to greater and greater numbers of offspring.
5. Adaption, the result is a population that is better suited–better adapted–to some aspect of the environment than it was before.

Question 4

Why does each species look different?

Answer 4

Each species has evolved to suit their environment. This means all species have different DNA that suits their living conditions.

Question 5

Why does no organism look the same, despite being the same species?

Answer 5

Every organism has slightly different genes and chromosomes that they have inherited from their parents. While they are largely the same as other organisms within their species, more specific traits are different.

Question 6

What are adaptions?

Answer 6

Adaptions are features that promote the survival and reproduction of an organism. Allowing a species to be better suited to it’s environment. It is a product of natural selection.

Question 7

What are the mechanisms that cause organisms to experience evolution?

Answer 7

Natural selection, mutation, genetic drift, gene flow, selective breeding,

Question 8

What are the three types of adaptation?

Answer 8

Structural/physical, behavioural, functional/physiological

Question 9

What is a functional/physiological adaptation?

Answer 9

Features resulting from metabolic or biological processes the organism’s body performs that improves chance of survival and reproduction. These processes are internal systems that affect an organism’s physiology or biochemistry.

Question 10

What is a structural/physical adaptation?

Answer 10

Physical features of an organism that improve its change of survival and reproduction.

Question 11

What is a behavioural adaptation?

Answer 11

Actions or activities of an organism that improves its chance at survival and reproduction. These are actions that the organism can control

Question 12

What are some examples of a behavioural adaption?

Answer 12

Burrowing, nocturnality, hibernation, mating tactics, migrating, climbing.

Question 13

What are some examples of a structural/physical adaptation?

Answer 13

Camel’s humps, giraffe’s long neck, cacti thorns, fish’s gills, snake’s flexible jaw, frog’s strong legs.

Question 14

What are some examples of a functional/physiological adaptation?

Answer 14

Poisons secreted by frogs/snakes/scorpions, changing body temperature, camouflage, releasing smelly gas, venom.

Question 15

What type of adaptation is the beak of a bird?

Answer 15

A structural/physical adaptation.

Question 16

What type of adaptation is a camel storing and breaking down fat in it’s humps?

Answer 16

A functional/physiological adaptation.

Question 17

What type of adaptation is a turtle returning to the beach they were born on to lay their eggs?

Answer 17

A behavioural adaptation.

Question 18

What happens to species unable to adapt?

Answer 18

They die off and eventually become extinct.

Question 19

What are embryological similarities?

Answer 19

Embryo’s of diiferent animals can show similarities. For example, fish embryos and human embryos both have gill slits.

Question 20

What are vestigial structures?

Answer 20

A feature passed down from ancestor that no longer has a purpose in the current form of the organism.

Question 21

What are homologous structures?

Answer 21

Features in different organisms that appear similar, due to their shared ancestry, but have different purposes.

Question 22

What is selective pressure?

Answer 22

A selective pressure is any reason for organisms with certain traits to have either a survival benefit or disadvantage. Selection pressures are external agents which affect an organism’s ability to survive in a given environment. E.g. predation, competition and disease.

Question 23

What should be the outcome of natural selection?

Answer 23

A species gradually becomes better suited to its environment

Question 24

What is geographic isolation?

Answer 24

When two populations of the same species are divided by some type of geographic event or object. When one group is stuck in a new environment.

Question 25

What is a selective agent?

Answer 25

An environment based factor which has huge impact on the mortality rate of any organism.

Question 26

What is speciation?

Answer 26

The development of different species over a long period of time, populations from the same species separate and develop their own characteristics.

Question 27

What is survival of the fittest?

Answer 27

The continued existence of organisms which are best adapted to their environment, with the extinction of others, as a concept in the Darwinian theory of evolution.

Question 28

How can you determine if different organisms are part of the same species?

Answer 28

They will be able to breed. If they can’t or won’t breed together, they are not the same species.

Question 29

What is the process of speciation?

Answer 29

1. Geographic isolation of populations.
2. Divergence in traits of separated populations. The population now has to adapt to a new environment and favourable traits become naturally selected.
3. Reproductive isolation of populations that maintains isolation when populations come into contact again. Meaning they can no longer breed together and are therefore identified as two different species.

Question 30

Is variation necessary for natural selection to occur?

Answer 30

Yes. Evolving organisms pass on the genetics that favored their success in survival. Genetics for organisms within one species vary, so the favourable ones are passed down.

Question 31

What is gene pool?

Answer 31

The stock of different genes in an interbreeding population.

Question 32

What is gene flow?

Answer 32

Transfer of genetic material into or out of a population. The movement of genes through different populations.

Question 33

What is an example of gene flow?

Answer 33

Bees collect pollen from one species of flower and carry it to a different species of flower.

Question 34

What is genetic drift?

Answer 34

Genetic drift is the change in frequency of an existing gene variant in the population due to random chance. Mostly occurs in small populations.

Question 35

What is an example of genetic drift?

Answer 35

Consider a population of rabbits with brown fur and white fur. Due to genetic drift, only the brown population might remain, with all the white ones eliminated.

Question 36

What is natural selection?

Answer 36

Natural Selection is the process where environmental factors dictate the evolution and changes of an organism.

Question 37

What happens in natural selection?

Answer 37

Individuals in a species show variation and the preferred variation is passed down.

Question 38

What is an example of natural selection?

Answer 38

Individuals in a species show variation and the preferred variation is passed down.
At one point, moths lived with two variations in colour, white or black. Industrial pollution began turning the environment dark. Natural selection dictated that black moths blended better. Moths began to reproduce mainly dark coloured offspring.

Question 39

What is artificial selection or selective breeding?

Answer 39

When specific organisms are selected to breed together for the purpose of creating an organism with desired traits.

Question 40

What is an example of artificial selection or selective breeding?

Answer 40

Dog breeding. Dogs are bred to create a new breed that has desired traits.

Question 41

Describe the process of artificial selection or selective breeding.

Answer 41

Humans choose an organism and choose the traits they do or do not want and breed to fit their desires.

Question 42

What are some of the differences between natural and artificial selection?

Answer 42

Natural selection is slower and has traits picked for survival.

Artificial selection is faster and has traits picked by human opinion.

Question 43

What is the tree of life or common ancestry?

Answer 43

All species are related, however some are more closely related than others. Because evolution doesn’t occur in succession, instead it branches off.

Question 44

What is mutation?

Answer 44

A change in the DNA sequence of an organism. Commonly results from errors in DNA replication during cell division.

Question 45

Why is mutation important to evolution?

Answer 45

It fuels the variability in populations and thus enables evolutionary change.

Question 46

Explain some common misconceptions.

Answer 46

Misconception #1 - An organism will birth a new species.
Reality #1 - A new species is created slowly, through natural selection. It happens over many generations.

Misconception #2 - All species have looked the same since forever.
Reality #2 - Species change and adapt to suit their environement so they can survive and reproduce.

Question 47

What are the 6 evidences of evolution and/or common ancestry? What do they show?

Answer 47

1. Fossils - Fossils have changed over time. Older fossils = simpler. Newer fossils = more complex.
   Therefore, evolution has led to increasing complexity. Tells us about organisms’ appearance and other organisms alive at the same time. Determines the period they came from. Transitional species
2. Comparative anatomy - Anatomy that suggests a common ansecter.
   - Homologous structures = similar structure different function e.g. human hand vs whale flipper
   - Amologous structure = similar function different structure e.g. bird vs. insect wings
3. Vestigial structures - features that were once useful for earlier ancestors but are no longer useful e.g. appendix
4. DNA/biochemical - More similar DNA means a more closely related species and evidence for common ancestry e.g. chimps share 97% of dna with humans - evidence for common ancestry
5. Geographical distribution - The more isolated a species is, the more unique it is. e.g. Aussie marsupial and monotremes
6. Embryology - Comparison of vertebrate (backbone) embryos show that they have similar developmental stages e.g. (chickens, tortoise , human) - shows common backboned ancestor