Evolution

Question 1

Why have changes occurred to life on Earth?

Answer 1

As a result of natural processes.

Question 2

What is the origin of life?

Answer 2

The origin of life on Earth is still unknown.

Question 3

What does evidence support?

Answer 3

Evidence supports the presence of organic
molecules in space, based on examination of
comets/meteorites.

Question 4

What suggests a possible location for the origin of single-celled organisms?

Answer 4

Observations of primitive life forms near volcanoes

and deep ocean hydrothermal vents

Question 5

What did scientists discover about Earth’s early atmosphere?

Answer 5

there was no oxygen in the early Earth’s atmosphere by studying rocks

Question 6

What is the source of oxygen?

Answer 6

cyanobacteria

Question 7

How did scientists identify the source of oxygen; cyanobacteria?

Answer 7

Analysis and understanding of photosynthesis
helped identify cyanobacteria as the source of
oxygen.

Question 8

What is a unifying hypothesis in the life sciences?

Answer 8

connection between these primitive prokaryotic
cells and all of the diverse forms of life that
followed.

Question 9

Who developed a theory about evolution?

Answer 9

Darwin. A similar theory was also independently

developed by Alfred Wallace.

Question 10

What did Darwin successfully do?

Answer 10

connected previously unrelated ideas into a coherent view of life

Question 11

What does Darwin’s theory suggest?

Answer 11

The theory explains how increased reproductive success of individuals with favourable heritable characteristics can lead to change in the genetic composition of a population.

Question 12

What is Darwin’s theory based on?

Answer 12

inferences based on observations.

Question 13

How is evolution measured?

Answer 13

Although natural selection involves interactions
between organisms and their environment evolution is
measured by the changes in populations.

Question 14

Why study natural selection?

Answer 14

increase understanding of the relationship between selective environmental pressures and survival of different organisms.

Question 15

What was Darwin’s evidence based on?

Answer 15

geographical distribution of species and the fossil

record

Question 16

What has led to new interpretations of the fossil record and a more complete picture of early animal evolution?

Answer 16

Continuing research and the development of

improved technologies

Question 17

Does artificial selection occur to natural ecosystems?

Answer 17

No

Question 18

What does artificial selection provide evidence for in terms of ecosystems?

Answer 18

species can change over time with selective

breeding

Question 19

How does modern molecular biology support evolution?

Answer 19

by comparing the DNA and proteins of current and

ancestral species.

Question 20

Why is there uncertainty about the ancestry of humans?

Answer 20

partly to incomplete fossil record and

misinterpretation of existing remains

Question 21

What established a bipedal ape and when?

Answer 21

Radioactive dating has established the existence of

a bipedal ape in Africa 4.4 million years ago

Question 22

What contributes to natural selection?

Answer 22

Development of tool making, hunting skills and

language

Question 23

Where is the original source of human migration?

Answer 23

Rift valley of Central Africa.

Question 24

What is the evidence for where the original source of human migration comes from?

Answer 24

evidence from mitochondrial DNA (mtDNA) and

Y chromosome

Question 25

What led to the reclassification of Neanderthal man as Homo sapiens neanderthalensis?

Answer 25

A newly mapped Neanderthal genome provided evidence of some interbreeding between modern man and Neanderthal man

Question 26

How have modern humans have demonstrated rapid cultural evolution?

Answer 26

minimal biological evolution.

Question 27

What are genes?

Answer 27

special sequences of A, T, G and C's in DNA that encode for proteins. Each gene is unique whose protein does a unique job

Question 28

What is in the cell nucleus? (Think of a library)

Answer 28

Cell nucleus - library Chromosomes - books (often come in pairs) Genes - sentences (are found in chromosomes) DNA - letters

Question 29

Why is there variation in living organisms?

Answer 29

due to variation in the sequence of A, T, G and C's in the genes inherited from the parents

Question 30

Why is a mutation in a gene called?

Answer 30

alleles

Question 31

When do mutations occur?

Answer 31

Inherited from parents or when the DNA is replicated before a cell divides into two

Question 32

What are two types of mutagen?

Answer 32

- ionising radiation (ultraviolet light, gamma rays) | - chemicals (found in cigarette smoke, burnt food)

Question 33

How are mutations corrected?

Answer 33

By DNA repair enzymes

Question 34

What is the basis of natural selection?

Answer 34

- environment is changing - variation can influence whether organisms are reproductively successful in certain environments - if successful, the organisms pass on their genes to the next generation - that particular variety will be more prominent in the population

Question 35

What is the result of natural selection?

Answer 35

change the variation in an organism's genome that it becomes a new species

Question 36

What does artificial selection prove?

Answer 36

species can change over time with selective breeding

Question 37

What is geographical isolation?

Answer 37

areas can become geographically isolated (earthquakes, ice ages, continental drift, water levels rising) resulting in individuals within the same species being unable to interbreed

Question 38

What is homologous anatomy?

Answer 38

underlying organisational similarities in species anatomy

Question 39

Why were Darwin's ideas criticised at first?

Answer 39

- went against accepted, prevalent views - difficult to prove with time spans involved - fossil record was incomplete to support darwin's ideas

Question 40

What are the problems with homologus anatomy?

Answer 40

some unrelated species have similar structures (bats and birds). These are called analogous structures and are an example of convergent evolution

Question 41

What is a clade?

Answer 41

grouping that includes a common ancestor and all the descendants (living or extinct) of that ancestor

Question 42

What is endosymbiosis?

Answer 42

a relationship between two organisms where one lives inside the cell

Question 43

What is mitochondria?

Answer 43

organelles found in cells, thought to have originated from bacteria living endosymbiotically in cells

Question 44

What do mitochondria do?

Answer 44

Aerobic respiration

Question 45

Where does the spine attach to the skull on bipedal apes?

Answer 45

In the centre of the head

Question 46

When and how was the first human like ancestor

Answer 46

Radio-dating fossils, 4.4 million years ago