Question 1

Explain the process (steps involved) of natural selection  step 1 and step 2

Accepted Answer

Step 1, Variation in the population already exists Step 2. A selection pressure is present in the environment.

Question 2

How does variation (new phenotypes) arise in a population

Accepted Answer

It arises in a population because of genetic diversity which ensures there is a variety of phenotypes

Question 3

Explain the process (steps involved) of natural selection step 3

Accepted Answer

Step 3. The individuals with the favourable traits are more likely to survive, reproduce and pass on the trait to their offspring

Question 4

Explain the process (steps involved) of natural selection step 4

Accepted Answer

Step 4. Over generations, the number of individuals with the favorable trait increases and the individuals with the unfavorable traits decreases

Question 5

Define the term species

Accepted Answer

The largest group of organisms in which any two individuals of any appropriate sexes can produce fertile offspring

Question 6

Using an example, explain the term artificial selection (selective breeding).

Accepted Answer

It is when organisms with particular traits are deliberately selected from a population to be the parents of the next generation.

Question 7

What is a hybrid? Why are hybrids such as the liger not considered their own species.

Accepted Answer

Hybrids are the offspring of two different species. They are not considered their own species because they cannot produce fertile offspring.

Question 8

Explain how artificial selection differs from natural selection. Provide and example.

Accepted Answer

The difference between the two is that natural selection happens naturally, but selective breeding only occurs when humans intervene. Horses are an example

Question 9

Outline the steps involved in allopatric speciation step 1 - 3

Accepted Answer

Step 1. Individuals are separated into two populations by a geographical barrier.
Step 2. Mutations occur independently in to two populations.
Step 3. Different selection pressure in the environment cause different phenotypes to be selected for.

Question 10

Outline the steps involved in allopatric speciation step 4

Accepted Answer

Step 4. When the two populations are brought back together they can no longer produce fertile offspring.

Question 11

How could researchers determine whether the organisms are a different species?

Accepted Answer

When they cannot have fertile offspring

Question 12

Why is variation important for survival in a species?

Accepted Answer

So they can survive and reproduce fertile offspring

Question 13

Define the term fossil

Accepted Answer

Fossils are preserved evidence in rocks and soils of organisms that once existed on earth

Question 14

Why are some organisms more likely to be fossilized over others?

Accepted Answer

When dead organisms are covered in sediment they are more likely to fossilised. Also if they protected from weather and if they have hard/ tough exoskeletons. Humid conditions with cold temperatures also help.

Question 15

Define the term homologous structure.

Accepted Answer

Fossils that have a similar structure with a differing function and come from a common ancestor.

Question 16

Define the term analogous structure.

Accepted Answer

Fossils that have a differing structure with a similar function and don't come from a common ancestor.

Question 17

Explain the term vestigial structure and provide some examples.

Accepted Answer

Vestigial structures are structures that organisms possess that have no apparent function and that resemble structures found in other organisms.

Question 18

Explain how the distribution of fossils can be used for evidence of continental drift.

Accepted Answer

One of the pieces of evidence that convinced scientists that continents moved was the distribution of fossils of particular species.

Question 19

List some of the skeletal changes that have occurred through evolution of various human-like species to modern day humans.

Accepted Answer

We now have smaller teeth with a less robust jaw size and pointy, short jaw with a larger skull size.

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Biology