6 Inheritance variation and evolution - Evolution

Question 1

What are fossils?

Answer 1

Remains of organisms from millions of years ago that are found preserved (in rocks, ice etc.)

Question 2

What are criterias for decay to occur?

Answer 2

Oxygen, bacteria (decomposers), correct temperature

Question 3

Describe the five steps of fossilisation by mineralisation.

Answer 3

1. Organism dies and falls to the ground; 2. Flesh decays, leaving the skeleton behind; 3. Bones are covered in sand/soil; 4. Bones become mineralised and turns into rock (fossil); 5. Rock with fossil emerges due to geological movement (eg. earthquake) and erosion occurs to reveal fossil

Question 4

What are the three different types of fossils that can be formed?

Answer 4

Mineralised skeleton; Undecayed due to trapped in ice or amber; Preserved traces of organisms (eg. footprints, leaves)

Question 5

Give 4 reasons why the fossil record is incomplete.

Answer 5

1. Many earliest life forms are soft-bodied; 2. Most organsisms did not become fossilised; 3. Most early fossils were destroyed by geological activity; 4. Many fossils are not yet found

Question 6

How is the fossil record helpful?

Answer 6

It shows how much organisms have changed and developed over time, and can show the environment and climate then

Question 7

Define ‘extinction’.

Answer 7

Permanent loss of all members of a species

Question 8

State three causes of extinction.

Answer 8

New predators; New diseases/pathogens; New/sucessful competitors

Question 9

What causes mass extinction? Suggest two examples of this cause.

Answer 9

Single catastrophic event that also affects climate over a long period (eg. asteroid collision, volcanic eruption)

Question 10

Suggest a chain of events initated by an asteroid collision that could lead to the extinction of dinosaurs.

Answer 10

Asteroid impact causes huge fires and earthquakes –> volcanic eruptions –> dust/ash cloud covers atmosphere –> less sunlight reaches the Earth surface –> temp drop massively + plants die –> loss of food source led to other animals’ extinction

Question 11

What is antibiotic resistance?

Answer 11

Bacteria becoming resistant means it cannot be killed by a certain antibiotic

Question 12

What causes antibiotic resistance?

Answer 12

Random mutations in bacteria/Bacteria sharing resistant genes

Question 13

Describe the steps in which a bacteria strain develops resistance to an antibiotic.

Answer 13

1. Mutation occurs in an individual bacterium within a population; 2. It survives and reproduces rapidly, making more bacteria with its resistant gene; 3. Overtime, all bacteria within the population have that gene

Question 14

Why can bacteria evolve quicker than other organisms?

Answer 14

Because bacteria can reproduce at a quick rate

Question 15

Suggest 3 methods to prevent and slow down the development of antibiotic-resistant strains.

Answer 15

1. Do not overuse antibiotics; 2. Patients finish antibiotic course every time; 3. Restrict agricultural use of antibiotics

Question 16

Why must patients finish their course of antibiotics every time?

Answer 16

To ensure all bacteria are killed by the antibiotic, so none can survive to mutate and develop resistantce

Question 17

Suggest 3 ways in which a hospital can reduce the spread of antibiotic-resistant strains.

Answer 17

Only use antibiotics if really needed; Use strain-specific antibiotics; Maintain high hygiene standards (eg. wash hands between patient visits); Isolate patients infected with resistant strain; Visitors wash hands as they enter and leave

Question 18

Why is it difficult to develop new antibiotics to combat the appearance of new antibiotic-resistant strains of bacteria?

Answer 18

The development of new antibiotics is expensive and slow (won’t be able to keep up)

Question 19

What does classification of organisms mean?

Answer 19

Organisation of living things into groups based on their similarities

Question 20

Name the person who developed the classification system.

Answer 20

Carl Linnaeus

Question 21

State the 7 heirarchical levels of the Linnaean classification system.

Answer 21

Kingdom, phylum, class, order, family, genus, species

Question 22

Every organism has a scientific name using a binomial system. What does binomial mean?

Answer 22

Two names

Question 23

Which language does the binomial naming system use?

Answer 23

Latin

Question 24

The binomial name of an organism is made up of two words. What does each word represent of that organism?

Answer 24

The first word is the genus; second word is the species

Question 25

What are the three rules of writing a binomial scientific name of a species?

Answer 25

First letter of the genus should be in capital; First letter of the species should be in small letter; Both need to be in italics when printed or underlined when hand-written

Question 26

Why do we use the binomial naming system?

Answer 26

Every organisms’ names would vary in different languages, but Latin is considered to be the old common language in which everyone can use/understand

Question 27

How many domains and kingdoms do scientists now consider in classification?

Answer 27

3 domains; 6 kingdoms

Question 28

Based on what knowledge were the three domains set?

Answer 28

Different biochemistry of cell and ribosomes, and how cells reproduce differently

Question 29

What are the three domains?

Answer 29

Archaea, bacteria, eukaryota

Question 30

What are the six kingdoms?

Answer 30

Archaebacteria, eubacteria, protista, fungi, plants, animals

Question 31

How is classification helpful?

Answer 31

Helps us to understand evolutionary and ecological relationships

Question 32

Name the type of models that are used to show how different organisms are related.

Answer 32

Evolutionary trees

Question 33

How are evolutionary trees made?

Answer 33

By looking at similarities and differences between different groups of organisms

Question 34

What aspects of knowledge would be considered when suggesting evolutionary relationships?

Answer 34

Similarties and differences in physical structures, genetics and biochemistry