Ib Biology 5.2

Front 1

Give three examples of variation in human populations.

Back 1

Height

Skin colour

Blood groups

Front 2

What is the original source of variation?

Back 2

Mutation (or gene mutation)

Front 3

Give all three sources of variation.

Back 3

Mutation, meiosis and sexual reproduction.

Front 4

What are adaptions?

Back 4

Adaptions are characteristics that make an individual suited to its environment and way of life.

Front 5

What are acquired characteristics? Are they considered adaptations?

Back 5

Acquired characteristics develop during a lifetime and cannot be inherited. Therefore they are not considered adaptations, as adaptations develop by natural selection and not per individual.

Front 6

What causes the struggle for existence within a population?

Back 6

Overproduction of offspring

Front 7

What does the struggle of existence mean?

Back 7

That there will be competition for resources and not every individual will obtain enough to allow them to survive and reproduce.

Front 8

What are the benefits of adapted individuals?

Back 8

They tend to survive and produce more offspring while the less well adapted tend to die or produce fewer offspring. This is natural selection.

Front 9

What is inheritance?

Back 9

Individuals that reproduce pass on characteristics to their offspring. Not all features are passed on.

Front 10

What is evolution by natural selection?

Back 10

The characteristics of a population will gradually change over generations.

Front 11

Why is there progressive change due to natural selection?

Back 11

Natural selection increases the frequency of characteristics that make individuals better adapted and decreases the frequency of other characteristics. This leads to an increase in the proportion of individuals in a population with characteristics that make them well adapted.

Front 12

What is heritability?

Back 12

The proportion of the variation due to genes.

Hint 12

This was observed on the Galápagos islands.

Front 13

Why is the development of antibiotic resistance an example of evolution?

Back 13

Bacteria show resistance within a few years to an antibiotic. Resistance to the antibiotic spreads to more and more species of the bacteria. Using the theory of evolution by natural selection, we can explain that the bacteria that are not resistant will decrease in number and the bacteria that are resistant will increase and the entire population will eventually be resistant.

Hint 13

Use the theory of evolution by natural selection to explain this question.

Front 14

Why is it possible for the evolution of antibiotic resistance in bacteria to have happened in just a few decades?

Back 14

1. There is often very widespread use of antibiotics.

2. Bacteria can reproduce very rapidly.

3. Populations of bacteria are often huge, increasing the chance of a gene for antibiotic resistance being formed by mutation.

4. Bacteria can pass genes on to other bacteria in several ways, including using plasmids.

Hint 14

There are four answers. Give at least three.

Front 15

True or false:

Natural selection can only occur if there is variation among members of the same species.

Back 15

True.

Hint 15

Understanding (book).

Front 16

Only meiosis can cause variation between individuals in a species.

Back 16

False. Mutation, meioisis and sexual reproduction all can.

Hint 16

Understanding (book).

Front 17

True or false:

Adaptations are characteristics that make an individual suited to its environment and way of life.

Back 17

True.

Hint 17

Understanding (book).

Front 18

True or false:

Species tend to produce less offspring than the environment can support.

Back 18

False. They tend to produce more.

Hint 18

Understanding (book).

Front 19

True or false:

Individuals that are better adapted tend to survive and produce fewer offspring while the less well adapted tend to survive or produce more offspring.

Back 19

False. Individuals that are better adapted tend to survive and produce more offspring while the less well adapted tend to die or produce fewer offspring.

Hint 19

Understanding (book).

Front 20

True or false:

Individuals that reproduce do not pass on characteristics to their offspring.

Back 20

False, they do.

Hint 20

Understanding (book).

Front 21

True or false:

Natural selection increases the frequency of characteristics that make individuals better adapted and decreases the frequency of other characteristics leading to changes within the species.

Back 21

This is true.

Hint 21

Understanding (book).