Download SBI3U Evolution Name: Problem Set: Evolution Answer the following

SBI3U
Evolution
Name:
Problem Set: Evolution
Knowledge/Understanding = ____/10
Communication =
____/6
Thinking =____/10
Application =____/4
Answer the following six questions showing full solution.
Communication
1. Study Figure=1 carefully and answer the following questions.
Figure 1
a)
If a new character (or trait) evolved at position 4, which of the species in the tree would
definitely not have the new trait?
[1 T, 1 A]
Species Q, R, S, & T would not the new trait
b)
Should you expect the ancestral species at position 5 to resemble S or T more closely?
[1 T, 1 A]
Ancestral species at position 5 would resemble species T more closely
c)
At which numbered position(s) could a derived character evolve that would eventually be
inherited by S?
[1 T, 1 A]
Positions 1, 3, & 5 could evolve a character trait that could be inherited by species S
d) Which species would you expect to be most ancient in appearance?
Species Q & V would be the most ancient in appearance
Created By: Karthiha Sridaran
[1 T, 1 A]
1
SBI3U
Evolution
Name:
2. Describe the endosymbiotic theory, using diagrams and suggesting evidence for this
theory.
[3K/U, 3C]
Mitochondria and chloroplasts are surrounded by two membranes. The outer membrane is
similar to eukaryotic cell membranes. The chemistry of the inner membrane resembles that of
eubacteria plasma membranes. Mitochondria and chloroplasts also have their own DNA, which
appears to be remnants of circular eubacterial chromosomes. The DNA also contains coding
sequences for various proteins and RNA, which resemble bacterial genes. Mitochondria and
chloroplasts replicate their own DNA and undergo cell division independently of the host cell’s
division.
3. Explain how mass extinctions are most likely the cause of multiple effects, rather than a
single cause.
[3K/U]
Many extinctions are the cause of ongoing evolutionary forces of competition and
environmental change. Factors that lead to ecological instability and global warming
can lead to mass extinctions. A single cause such as a meteorite collision would result in
the death of a large number of plants and animals, but not necessarily a mass extinction.
Created By: Karthiha Sridaran
2
SBI3U
Evolution
Name:
4. Compare Homologous, Analogous and Vestigial Organs using a chart.
Homologous
Common origin
Similar structure
Serves different functions
E.g. Forelimb of human and
whale
Analogous
Origin not common
Serves similar functions
E.g. Wings of birds and bees
[3 T, 3 C]
Vestigial
Non-functioning structure
Homologous to fully
functioning structures in
closely related species
E.g. the human appendix
5. Explain what the following quotation is attempting to imply. “It is rare that a precision
machine is improved by a random change in the instruction for making it.” Think in
terms of beneficial, detrimental and neutral mutations.
[3 T]
Mutations to the genetic code of an organism can be neutral, harmful, or beneficial. A neutral
mutation has no immediate effect on fitness. A harmful mutation is one that impairs the
proper operation of a gene product or regulatory function. A beneficial mutation is one where
a selective advantage is gained. Random changes to the genetic code are much more likely to
be harmful or neutral. Thus, a random change to the instructions for making a machine are
more likely to have a negative effect than a beneficial effect.
6. Give one example of an animal that went through the process of gradualism and one
that went through the process of punctuated equilibrium. Explain how these species
went through the process.
[4 K/U]
Humans are an example of gradualism. Humans follow a linear pattern of evolution
instead of fast advancements and spontaneous spurts of rapid evolution.
The finches of the Galapagos Islands are an example of punctuated equilibrium.
The appearance of new niches gave sudden rise to new species of finches.
Once the new species of finches adapted to their environment, they did not
undergo significant changes for long periods of time.
Created By: Karthiha Sridaran
3