BIOB51 MIDTERM 1 EXAM QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTIONS VERIFIED
Why is it often difficult to conceptualize biological evolution?
We cannot conceptualize the concept of time
What is the difference between a theory and a fact?
A theory is supported by facts
What is the relationship between theory and law?
Laws describe, theories explain
Why is it important that we have a grasp on the concept of time, in an
evolutionary sense?
That expanse of time defines the realm of biological possibility in which life in its
extraordinary diversity has evolved
How does an understanding of evolution inform us about all aspects of life and
the interconnectivity of life?
By understanding evolution we can understand why the natural world is the way it is,
simulates and differences among and between species, geographical distribution of
species and incredible adaptations (and weaknesses) of living things
Why do we know that whales are mammals?
Whales share numerous synapomorphies with mammals: mammary glands, three
middle ear bones, hair (in developing embryos)
Homology
,similarity resulting from common ancestry, front teeth on human and beaver and
elephant tusks. Mammalian ear bones are homologous to early synapsid jaw bones
What is Pakicetus and how does it fit within the phylogeny of cetaceans?
"Whale of Pakistan", oldest fossil found of cetaceans. They were shaped by shallow
streams that only flowed seasonally through what was otherwise a hot, dry landscape. A
whale that spent some time on land. Thick involucrum, bottlenose dolphin
Convergent evolution=
Homoplasy
What is a synapomorphy
a derived form of a trait that is shared by a group of related species (one that evolved in
the immediate common ancestor of the group and was inherited by all its descendants)
Order of the evolutionary relationship between extinct and living cetaceans
slide 25, lec 2
What are isotopic analyses?
Separates isotopes on the basis of small but significant differences in mass
How was 18O/16O used in our understanding of saltwater and freshwater
cetaceans?
Scientists observed seawater has more oxygen atoms with 10 neutrons that freshwater,
animals that live on land and sea reflect this difference in oxygen atoms in their bones.
Living whales and dolphins have a larger percentage of heavier oxygen than land
mammals.
How is it that modern cetaceans do not have hindlimbs
, Hindlimbs begin to form but fail to fully develop. Changes in gene expression led to
hindlimb loss.
What is baleen? What clue does it provide about cetaceans evolution?
The mysticetes trap small animals with their baleen, they get a huge amount of prey.
Genes for building teeth have been disabled
What are the main steps in the life cycle of SARS-CoV-2?
1. Spike protein on the Cov-2 virus bind to cell-surface ACE2 receptors
2.The virus hijacks the host's cellular machinery to express viral proteins and replicate
the viral RNA, making new coronaviruses.
The new viruses are released, some of them carry the altered spike protein.
3. Occasionally a mutation occurs during replication, altering the tip of the spike protein
produced
Describe how mutations spread in viruses
Strains with beneficial mutations increase in frequency via natural mutations
What is current hypothesis for the origin of SARS-CoV-2?
Bats
Describe viral reassortment
When 2 or more strains come together in process of reassortment to create a new virus
What is Special Creation?
Notion dominated Western thought about the nature of organisms for >2000yrs
1. Species are independent (unrealted)
2. Life on Earth is young (~6000 years old)
3. Species are immutable (incapable of change)
ANSWERS WITH COMPLETE SOLUTIONS VERIFIED
Why is it often difficult to conceptualize biological evolution?
We cannot conceptualize the concept of time
What is the difference between a theory and a fact?
A theory is supported by facts
What is the relationship between theory and law?
Laws describe, theories explain
Why is it important that we have a grasp on the concept of time, in an
evolutionary sense?
That expanse of time defines the realm of biological possibility in which life in its
extraordinary diversity has evolved
How does an understanding of evolution inform us about all aspects of life and
the interconnectivity of life?
By understanding evolution we can understand why the natural world is the way it is,
simulates and differences among and between species, geographical distribution of
species and incredible adaptations (and weaknesses) of living things
Why do we know that whales are mammals?
Whales share numerous synapomorphies with mammals: mammary glands, three
middle ear bones, hair (in developing embryos)
Homology
,similarity resulting from common ancestry, front teeth on human and beaver and
elephant tusks. Mammalian ear bones are homologous to early synapsid jaw bones
What is Pakicetus and how does it fit within the phylogeny of cetaceans?
"Whale of Pakistan", oldest fossil found of cetaceans. They were shaped by shallow
streams that only flowed seasonally through what was otherwise a hot, dry landscape. A
whale that spent some time on land. Thick involucrum, bottlenose dolphin
Convergent evolution=
Homoplasy
What is a synapomorphy
a derived form of a trait that is shared by a group of related species (one that evolved in
the immediate common ancestor of the group and was inherited by all its descendants)
Order of the evolutionary relationship between extinct and living cetaceans
slide 25, lec 2
What are isotopic analyses?
Separates isotopes on the basis of small but significant differences in mass
How was 18O/16O used in our understanding of saltwater and freshwater
cetaceans?
Scientists observed seawater has more oxygen atoms with 10 neutrons that freshwater,
animals that live on land and sea reflect this difference in oxygen atoms in their bones.
Living whales and dolphins have a larger percentage of heavier oxygen than land
mammals.
How is it that modern cetaceans do not have hindlimbs
, Hindlimbs begin to form but fail to fully develop. Changes in gene expression led to
hindlimb loss.
What is baleen? What clue does it provide about cetaceans evolution?
The mysticetes trap small animals with their baleen, they get a huge amount of prey.
Genes for building teeth have been disabled
What are the main steps in the life cycle of SARS-CoV-2?
1. Spike protein on the Cov-2 virus bind to cell-surface ACE2 receptors
2.The virus hijacks the host's cellular machinery to express viral proteins and replicate
the viral RNA, making new coronaviruses.
The new viruses are released, some of them carry the altered spike protein.
3. Occasionally a mutation occurs during replication, altering the tip of the spike protein
produced
Describe how mutations spread in viruses
Strains with beneficial mutations increase in frequency via natural mutations
What is current hypothesis for the origin of SARS-CoV-2?
Bats
Describe viral reassortment
When 2 or more strains come together in process of reassortment to create a new virus
What is Special Creation?
Notion dominated Western thought about the nature of organisms for >2000yrs
1. Species are independent (unrealted)
2. Life on Earth is young (~6000 years old)
3. Species are immutable (incapable of change)
