B15 Genetics & Evolution Flashcards
In evolution, birds are most closely related to
a) Mammals
b) Fish
c) Reptiles
c) Reptiles
Complete the following sentence:
A study of fossils give evidence for the theory of…
evolution.
Outline several possible causes for the extinction of organisms.
- changes to the environment
- new competitors
- new diseases
- new predators
- volcanic eruptions
- asteroid collisions
Darwin suggested the theory of evolution by _____ selection.
natural
Darwin’s theory of evolution says that all species of living things have evolved from ____ life forms.
Complete the sentence with:
artificial / complex / simple
simple
Most scientists believe that life first developed about three ____ years ago.
Complete the sentence with:
billion / million / thousand
billion
Darwin’s theory of evolution was only slowly accepted by other people. Give three reasons why.
- Religious opposition.
- Genes and DNA not known about.
- Insufficient evidence.
Stages of evolution can be shown by an evolutionary ___.
Complete the sentence with:
web / tree / storm.
tree
Scientists continue to adjust their models of evolutionary relationships.
This is primarily due to:
a) new evidence from fossils
b) more powerful computers
c) new interpretations of religious texts
a) new evidence from fossils
How are fossil footprints formed?
Animal walks on soft material. The material dries out and hardens into rock.
Other than fossil footprints, how else are fossils formed?
- Preserved bones.
- Animals trapped in amber.
- Bones replaced by minerals.
How can fossils give evidence for evolution?
Older fossils change with time.
Scientists are uncertain about how life began on Earth. Why?
No fossils survived from early life.
Many early life forms were soft bodied so did not leave fossils.
A baby mammoth died 40,000 years ago and its body froze in ice. Explain why the body of the baby mammoth did not decay.
Too cold for the enzymes in microorganisms to work and decompose it.
Mammoths are extinct. What does extinct mean?
No longer exist.
