B6 - life on Earth - Past, Present, and Future

Question 1

What is the process natural selection (3)

Answer 1

1. advantageous genetic variant/allele
2. more likely to survive and reproduce
3. and pass on genetic variant
   this process may continues over many generations, leading to all of them having the advantageous genetic variant.

Question 2

What is evolution?

Answer 2

it’s the change of inherited characteristics of a population over several generations, through the process of natural selection

Question 3

What is speciation?

Answer 3

the formation of 2 or more species from the original species

Question 4

What is a fossil?

Answer 4

Any trace of an animal or plant that lived long ago. Most commonly found in rocks

Question 5

how can we observe fossils as evidence for evolution?

Answer 5

By arranging fossils in chronological order, gradual changes in organisms can be observed. This provides evidence, as it shows how species have changed and developed over many years.

Question 6

how can bacteria show evolution?

Answer 6

1. develops random mutations in DNA, which introduces new variants in population, changing phenotype.
   e.g a bacterium could become less affected by an antibiotic. (survives)
2. this leads to the resistant variant being passed on to offspring and becoming more common overtime
   (natural selection)

Question 7

What is selective breeding?

Answer 7

Is mating the best organisms to get good offspring.

Question 8

what is the process of selective breeding? (3)

Answer 8

the parent organisms with the best characteristic are selected
they breed
the best of the offspring are selected and bred
process is repeated over several generations

Question 9

Problems with selective breeding

Answer 9

1. reduces gene pool due to inbreeding
2. inbreeding can cause health problems as there is more chance of developing harmful genetic disorders
3. badly affected if a disease arrives

Question 10

What is classification?

Answer 10

the process of organizing organisms into groups based on their characteristics and evolutionary relationships

Question 11

How do scientists use DNA analysis

Answer 11

scientists can use DNA sequencing to compare particular genes or entire genomes using samples of tissue.
they look for similarities
the more similar the DNA sequences between species, the more closely related they are and are more likely to classified in the same group

Question 12

How can scientists use DNA sequencing to estimate speciation? (2)

Answer 12

scientists can estimate how frequently how mutations happen.
by finding the number of different genetic variants between 2 species, scientists can estimate speciation

Question 13

what is biodiversity a combination of? (3)

Answer 13

• diversity of living organisms in a particular area
• diversity of different genes and alleles in a particular area
• diversity of different ecosystems in a particular area

Question 14

human interactions can reduce biodiversity (3)

Answer 14

1) increasing human population
2) industrialisation; more raw materials, more waste products
3) globalisation

Question 15

why human interactions can destroy ecosystems and biodiversity (2)

Answer 15

1) habitat destruction can reduce the amount of land and resources available to other animals and plants
2) waste/pollution; toxic chemicals from industry can pollute oceans, affecting plants/animals that rely upon them

Question 16

What does sustainability mean?

Answer 16

meeting the needs of today’s population without harming the environment or using up resources, so that future generations can still meet their own needs.

Question 17

protecting specific species (2)

Answer 17

1. protected in their natural habitat e.g by banning the hunting of some species
2. breeding programs in captivity to increase the number of species before releasing into the wild

Question 18

protecting habitats and ecosytems

Answer 18

1) setting aside specific protected areas helps conserve entire ecosystems by restricting the development of land

Question 19

Economic issues of maintaining biodiversity

Answer 19

• expensive to conserve species or habitats
• selling natural resources may help boost the country’s economy, but a negative effect on the country’s ecosystems

Question 20

moral issues of maintaining biodiversity

Answer 20

• the conversation of some endangered species may have no obvious benefit for humans
• morally wrong from to stop developing countries use raw materials that could boost economy