Genetics and evolution

Question 1

What are fossils?

Answer 1

Remains of organisms from many thousands of years ago found in rocks

Question 2

What are the three ways fossils forms in rocks

Answer 2

• Skeleton made of rock
• Casts and impression from the ground (clay)
• Preservation in places where no decay
  happens

Question 3

Why are fossils so important?

Answer 3

evidence for evolution as we can see the small incremental changes over millions of years

Question 4

Gradual replacement by minerals

Answer 4

bones decay really slowly, it means as they decay they are gradually replaced by minerals, forming rock-like substances.
- shaped as the exact original structures

Question 5

Casts and impressions

Answer 5

When an organism is buried in a soft material like clay and later it hardens while the organism decays leaving a cast the same size and shape.

Question 6

Examples of casts

Answer 6

• Animal’s burrow
• Plant’s roots

Question 7

Preservation

Answer 7

Organisms stay completely intact in amber and tar pits
- no oxygen or moisture so decay microbes cant
survive

can happen in:
- glaciers (too cold)
- Peat bogs (too acidic)

Question 8

Why does know one know how life began?

Answer 8

• many early forms of life were soft-bodied and
  tissue tends to decay away completely
  
  • so fossils records is incomplete
• Fossils formed millions ago may been destroyed by geological activity.
  
  • Movement of tectonic plates may crush
    fossils

Question 9

Extinction

Answer 9

No individuals of a species remains

Question 10

Reasons for extinction

Answer 10

• Environment changes too quickly (destruction
  of habitats
• New predator kills them all (human hunting(
• New disease kills them all
• Cant compete with another new species for
  food
• A catastrophic event (volcanic eruption or
  collision with asteroid)

Question 11

What are the 2 things Wallace is known for?

Answer 11

• Theory of speciation
• Studying warning coloration in animals

Question 12

Species

Answer 12

A group of similar organisms that can reproduce to give fertile offsprings

Question 13

Speciation

Answer 13

The development of a new species

Question 14

How does speciation occur

Answer 14

When population of the same species becomes so different they can no longer successfully interbreed to produce fertile offsprings

Question 15

What are the two things that leads to speciation?

Answer 15

• Natural selection
• Isolation

Question 16

Isolation

Answer 16

Population of species are separated due to a physical barrier
- might have different climates which could lead
to different characteristics due to natural
selection

Question 17

Examples that causes isolation

Answer 17

• Floods
• Earthquakes

Question 18

Antibiotics

Answer 18

Drugs that can kill bacteria

Question 19

How does an antibiotic resistant strain population increase during a short amount of time?

Answer 19

It is able to live much longer and reproduce rapidly.

Question 19

Antibiotic resistant strain

Answer 19

A bacteria developing random mutations in their DNA making them resistance to a particular antibiotic
- This gene becomes more common in the
population due to natural selection

Question 20

Superbugs

Answer 20

Bacteria that are resistant to mostly known antibiotics

Question 21

Name a common superbug

Answer 21

MRSA

Question 22

Reasons why antibiotic resistance is becoming more common

Answer 22

• overuse
• people not taking the full course of their
  antibiotics so not all the bacteria are killed
• farming (in food of healthy animals to prevent
  them getting ill and grow faster)

Question 23

How does an antibiotic resistance rise

Answer 23

-A population of a bacteria infect somebody

-That person takes antibiotics to kill the bacteria

-Some bacteria have a random mutation that makes them less susceptible to the antibiotic than others (or completely resistant to it)

The antibiotics kill all the bacteria except those that are resistant

The resistance strains of bacteria now have more resources to grow and multiply

More mutations may arise, leading to greater resistance

There is now a strain of bacteria that can’t be killed by antibiotics, which we call antibiotic resistance

Question 24

How did Carl Linnaeus classify animals

Answer 24

By their characteristics and bones structure

Question 25

Linnean system

Answer 25

-Kingdom
-Phylum
-Class
-Order
-family
-Genus
-Species

Question 26

Binomial system

Answer 26

‘genus’‘species’
e.g. Homosapiens

Question 27

Why has classification change overtime?

Answer 27

• Knowledge of biochemical process
• Microscopes (for internal structures)

Question 28

3 domain system

Answer 28

• Archaea (primitive bacteria)
• Eukaryota (us)
• Bacteria (true bacteria)