Inheritance, Variation and Evolution Flashcards
(19 cards)
Give one reason why only the bones of the body so the Siberian Rhinoceros became fossils
Bones did not decay
What is the purpose of thick fleshy leaves
Store water
Describe how the adaptation of spending the daytime on an underground burrow helps the Jerboa to survive in the desert
Cooler underground
So loses less water
What is a fossil
Remains of an organism
From a long time ago
4 causes of extinction
Ice age
Global warming
Asteroid collision
New Diseases
Give three reasons why the fossil record is not clear for older species
Fossils buried deeper so harder to find
Fossils smaller so harder to find
Fossils are more likely to be destroyed by geological activity
Advantage of mass extinction events
In terms of evolution
Allows evolution of new species
Three reasons why the dodo became extinct soon after the arrival of humans
Humans hunted the dodo
Humans ate the dodo’s food
Disease introduced by humans
Explain how cutting down trees by cutting certain areas first and then other areas later stops the biodiversity of the rainforest being reduced
Displaced animals can move to adjacent areas
Where suitable habitat is found
Seeds return to deforested areas from other forested areas so the trees begin to grow back
So provide animals food and animals can return to re growing area
And there is sufficient time for regeneration
Give one reason why scientists have found very few fossils of the earliest life forms
Organism were soft-bodied
Suggest how the fossil of the fish was formed
The fish dies and is buried in sediment
The soft parts decayed
And mineralisation occurred
Give one way a fossil may be formed
Animal dies and body is covered in sediment
Who proposed the theory that changes in an organism could be inherited
Jean Baptiste Lamarck
Explain how the fossil of the snake may have formed
Snake is covered in sediment
The soft parts decay
Bones are replaced by minerals
Suggest how scientists could prove that the six types of Island Fox belong to the same species
The two interbreed
And produced fertile offspring successfully
Explain how a change in one amino acid in an enzyme molecule could stop the enzyme working
Different protein made
Active site changed
So substrate does not fit
How does the fat store and a hard mouth help the animal survive in the desert
Fat store: can be metabolised
Hard mouth: not damaged by spines on plants
Give the reason why the gene does not have to be taken from the cells in the pituitary gland
White blood cells have the same DNA
Explain how the structure of Enzyme 1 allows the enzyme to cut the gene for tetracyclines resistance but not the gene for ampicillin resistance
Enzyme has a specifically shaped active site
The 2 antibiotic resistant genes have different bases
Only Tetracycline gene is complementary tothe enzyme
