bio

?
What type allele is needed for polydactyl syndrome?
A dominant allele.
1 of 12
Wha are the symptoms of polydactyl syndrome?
Extra digits on hands and feet.
2 of 12
What is the definition of a fossil?
The preserved remains of an animal, plant or other organism. Usually to qualify as a fossil, the remains must be more than 10 000 years old.
3 of 12
Where are fossils usually found?
Sedimentary rocks.
4 of 12
How are fossils formed?
An organism dies. It becomes buried under layers of sediment. Over time, soft body parts rot away, but hard parts,(bones), remain. Bones are compacted under layers of sediment. Materials/minerals replace body parts over many years. Fossils are formed
5 of 12
How also can fossils form?
Dead organisms preserved in amber/peat bogs/tar pits/ice. Casts/impressions e.g footprints covered in sediments which become rocks and preserve casts. Hard body parts e.g bones/shells/leaves covered in sediments & body parts are replaced by minerals.
6 of 12
Why are there maps in the fossil records?
Soft bodied animals decay completely and leave no remains to fossilise. Fossils may be destroyed due to natural sisters like earthquakes or volcanoes.
7 of 12
What can we learn from fossils?
How much or how little organisms have changed or evolved s life on earth has developed.
8 of 12
How do species become extinct?
Speciation. Changes in the environment e.g global warming. Habitats destroyed. New predators. New diseases. Catastrophes, e.g volcano/earthquake. Completion.
9 of 12
What is speciation?
How new species are formed.
10 of 12
What is a species?
Members of the same species that can breed successfully to produce fertile offspring.
11 of 12
How do new species form?
Isolation: members of the same species become geographically separated. Variation: there's a variation in population. Natural selection: organisms adapt to environments. Speciation: Over years they adapt & are new species so won't make fertile babies
12 of 12

Other cards in this set

Card 2

Front

Wha are the symptoms of polydactyl syndrome?

Back

Extra digits on hands and feet.

Card 3

Front

What is the definition of a fossil?

Back

Preview of the front of card 3

Card 4

Front

Where are fossils usually found?

Back

Preview of the front of card 4

Card 5

Front

How are fossils formed?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

Biology
B6
See all Biology resources »See all DNA and inheritance resources »