natural selection

Question 1

explain how bacteria have evolved so that antibiotics are less effective

Answer 1

-some bacteria have a mutation
-which makes them antibiotic resistant
-only these resistant bacteria survive
-the resistant bacteria reproduce
-passing on alleles to offspring
-and increasing in population

Question 2

guinea pigs stay still in the presence of danger. describe how this behaviour has evolved by natural selection.

Answer 2

-some guinea pigs have a mutation that allows them to stay still
-only those guinea pigs survive predators
-they reproduce
-passing on alleles to offspring

Question 3

the red blood cells of llamas can absorb more oxygen that animals that live at low altitudes. explain how llamas have evolved by natural selection to live at high altitudes

Answer 3

-there is variation in the population caused by a mutation
-variation in haemoglobin/how much oxygen absorbed
-the llamas survive
they reproduce
-pass on alleles to offspring

Question 4

fennec foxes have large ears and a thin body. explain how they have evolved by natural selection

Answer 4

-there is variation in population caused by a mutation
-variation in the size of ears- heat loss, keep cool
-enables survival
-fox breeds/reproduces
-passes on alleles to offspring

Question 5

explain how humans have less body hair then older generations by natural selection

Answer 5

-variation in the amount of body hair caused by a mutation
-less hair increased heat loss/started to wear clothes
-survive and reproduce
-pass on alleles to offspring

Question 6

name the type of organism that make antibiotics

Answer 6

fungi/bacteria/penicillium

Question 7

name the type of pathogen that is killed by antibiotics

Answer 7

bacteria