BIO 148
BIO 148 EXAM 4 REVIEW QUESTIONS
AND ANSWERS GRADED A+ 2026
Explain how the human microbiome is developed -Correct Answer ✔--The microbes in
the human body come from the womb, in the birth canal, breast milk, and surroundings
-As a baby a lot of changes in the human microbiome occur and stabilizes after about 3
years
Define the term niche and relate it to habitats within the human body -Correct Answer
✔--An ecological niche is a range of environmental conditions and resources used by an
organism. Ex: food, temperature, pH, humidity, habitat, etc
-Niches relate to habitats within the human body because each part of our body is a
different niche, different organisms that are adapted to different conditions live in
different areas
List the functions of microorganisms in the human body -Correct Answer ✔--Nutrition:
Synthesize vitamins, help digest food, regulate metabolism
-Immunity: Recognize "good" vs. "bad" microbes
-Protection from infection: Crowd out "bad" species, produce antimicrobials
-Protective barriers: Strengthen gut barrier
-Organ development: Immune system, brain development
Explain how the loss of an important species can have far-reaching effects on the
ecosystem -Correct Answer ✔-Important species can have a large role in shaping an
ecosystem meaning if a big chunk of an ecosystem is lost and all the roles the species
did is missing, then the ecosystem won't be able to function the same.
Explain how the principle of competitive exclusion relates to the human microbiome -
Correct Answer ✔--Competitive exclusion is if two species occupy the same niche, one
species will outcompete the other
-Symbiotic microbes on skin and gut can competitively exclude pathogens
-Ex: C. dificile can grow in the intestines if there are niches available (usually due to
antibiotic use)
Explain how antibiotics work to treat bacterial infections but can also harm symbiotic gut
bacteria -Correct Answer ✔--Antibiotics work because they inhibit a process that is
unique to bacteria
-Antibiotics can harm symbiotic gut bacteria if they are over used
-The overuse of antibiotics is bad because it kills the good bacteria, opens up niches for
harmful species, selection for resistant microbes, and if used a lot during childhood it
can increase the risk of inflammatory diseases
BIO 148
,BIO 148
Explain why it is harder to treat fungal infections than bacterial infections in humans -
Correct Answer ✔-It is harder to treat fungal infections in humans because fungus is
more closely related to humans (eukaryotes) than bacteria (prokaryotes) so it is difficult
to find a drug that kills the fungus and not the animal
Probiotics -Correct Answer ✔--May help restore "good" microbes in your gut
-Enhances growth of beneficial species
What are some fungi that can cause disease? -Correct Answer ✔--Athletes foot
-Thrush
What are some protists that can cause disease? -Correct Answer ✔--Malaria (carried by
mosquitoes)
-Toxoplasmosis (life cycle completed in cats)
Describe the evolutionary relationship of land plants to other eukaryotes and identify
their most closely related eukaryote -Correct Answer ✔-All land plants:
-Are multicellular eukaryotes
-Have a cell wall of cellulose
-Are photoautotrophs
-Have chloroplasts as the site of photosynthesis
-Plants evolved from green algae so, their most closely related eukaryote is a protist
Describe the evolutionary significance and identify which groups of plants have the
adaptation of cuticles -Correct Answer ✔--A water tight sealant to prevent water loss
-Present in all land plants
Describe the evolutionary significance and identify which groups of plants have the
adaptation of stomata -Correct Answer ✔--Are pores for gas exchange
-Present in all land plants
Describe the evolutionary significance and identify which groups of plants have the
adaptation of roots and shoots -Correct Answer ✔--Helps to get water to leaves
-Water goes in the roots/ shoots and travel up to the leaves where photosynthesis will
happen
-Present in ferns, gymnosperms, and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of vascular tissue -Correct Answer ✔--Tubes to move water
-Important for support of the plant on land
-Present in ferns, gymnosperms, and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of lignin -Correct Answer ✔--In the cell walls of land plants
-Provide strength for the plant
BIO 148
, BIO 148
-Present in ferns, gymnosperms, and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of leaves -Correct Answer ✔--Have a large surface area for light absorption
-Photosynthesis takes place here
-Present in ferns, gymnosperms, and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of pollen -Correct Answer ✔--Carries sperm dispersed by wind
-Important for reproducing on land
-Present in gymnosperms and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of seeds -Correct Answer ✔--Contains embryo
-Provides a food supply
-Has a protective coat
-Important for reproducing on dry land
-Present in gymnosperms and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of flowers -Correct Answer ✔--Allows direct pollination of egg by animals
-Present in all angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of fruits -Correct Answer ✔--A modified ovary/ seed dispersal
-Present in SOME angiosperms
Importance of land plants adapting UV protection -Correct Answer ✔--Flavonoid
pigments that help protect against intense sunlight
-Adaption is present in all land plants
Importance of land plants adapting retention of zygote on parent -Correct Answer ✔--
Provides protection and nourishment for zygote
-Adaption is present in all land plants
Importance of land plants adapting ovaries -Correct Answer ✔--Provides protection for
the gametes
-Present in all angiosperms
What are the effects of reproductive isolation on the evolution of new species? -Correct
Answer ✔--There would be no interbreeding or fertile offspring
-Organisms would be different species if they are reproductively isolated from each
other
BIO 148
BIO 148 EXAM 4 REVIEW QUESTIONS
AND ANSWERS GRADED A+ 2026
Explain how the human microbiome is developed -Correct Answer ✔--The microbes in
the human body come from the womb, in the birth canal, breast milk, and surroundings
-As a baby a lot of changes in the human microbiome occur and stabilizes after about 3
years
Define the term niche and relate it to habitats within the human body -Correct Answer
✔--An ecological niche is a range of environmental conditions and resources used by an
organism. Ex: food, temperature, pH, humidity, habitat, etc
-Niches relate to habitats within the human body because each part of our body is a
different niche, different organisms that are adapted to different conditions live in
different areas
List the functions of microorganisms in the human body -Correct Answer ✔--Nutrition:
Synthesize vitamins, help digest food, regulate metabolism
-Immunity: Recognize "good" vs. "bad" microbes
-Protection from infection: Crowd out "bad" species, produce antimicrobials
-Protective barriers: Strengthen gut barrier
-Organ development: Immune system, brain development
Explain how the loss of an important species can have far-reaching effects on the
ecosystem -Correct Answer ✔-Important species can have a large role in shaping an
ecosystem meaning if a big chunk of an ecosystem is lost and all the roles the species
did is missing, then the ecosystem won't be able to function the same.
Explain how the principle of competitive exclusion relates to the human microbiome -
Correct Answer ✔--Competitive exclusion is if two species occupy the same niche, one
species will outcompete the other
-Symbiotic microbes on skin and gut can competitively exclude pathogens
-Ex: C. dificile can grow in the intestines if there are niches available (usually due to
antibiotic use)
Explain how antibiotics work to treat bacterial infections but can also harm symbiotic gut
bacteria -Correct Answer ✔--Antibiotics work because they inhibit a process that is
unique to bacteria
-Antibiotics can harm symbiotic gut bacteria if they are over used
-The overuse of antibiotics is bad because it kills the good bacteria, opens up niches for
harmful species, selection for resistant microbes, and if used a lot during childhood it
can increase the risk of inflammatory diseases
BIO 148
,BIO 148
Explain why it is harder to treat fungal infections than bacterial infections in humans -
Correct Answer ✔-It is harder to treat fungal infections in humans because fungus is
more closely related to humans (eukaryotes) than bacteria (prokaryotes) so it is difficult
to find a drug that kills the fungus and not the animal
Probiotics -Correct Answer ✔--May help restore "good" microbes in your gut
-Enhances growth of beneficial species
What are some fungi that can cause disease? -Correct Answer ✔--Athletes foot
-Thrush
What are some protists that can cause disease? -Correct Answer ✔--Malaria (carried by
mosquitoes)
-Toxoplasmosis (life cycle completed in cats)
Describe the evolutionary relationship of land plants to other eukaryotes and identify
their most closely related eukaryote -Correct Answer ✔-All land plants:
-Are multicellular eukaryotes
-Have a cell wall of cellulose
-Are photoautotrophs
-Have chloroplasts as the site of photosynthesis
-Plants evolved from green algae so, their most closely related eukaryote is a protist
Describe the evolutionary significance and identify which groups of plants have the
adaptation of cuticles -Correct Answer ✔--A water tight sealant to prevent water loss
-Present in all land plants
Describe the evolutionary significance and identify which groups of plants have the
adaptation of stomata -Correct Answer ✔--Are pores for gas exchange
-Present in all land plants
Describe the evolutionary significance and identify which groups of plants have the
adaptation of roots and shoots -Correct Answer ✔--Helps to get water to leaves
-Water goes in the roots/ shoots and travel up to the leaves where photosynthesis will
happen
-Present in ferns, gymnosperms, and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of vascular tissue -Correct Answer ✔--Tubes to move water
-Important for support of the plant on land
-Present in ferns, gymnosperms, and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of lignin -Correct Answer ✔--In the cell walls of land plants
-Provide strength for the plant
BIO 148
, BIO 148
-Present in ferns, gymnosperms, and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of leaves -Correct Answer ✔--Have a large surface area for light absorption
-Photosynthesis takes place here
-Present in ferns, gymnosperms, and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of pollen -Correct Answer ✔--Carries sperm dispersed by wind
-Important for reproducing on land
-Present in gymnosperms and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of seeds -Correct Answer ✔--Contains embryo
-Provides a food supply
-Has a protective coat
-Important for reproducing on dry land
-Present in gymnosperms and angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of flowers -Correct Answer ✔--Allows direct pollination of egg by animals
-Present in all angiosperms
Describe the evolutionary significance and identify which groups of plants have the
adaptation of fruits -Correct Answer ✔--A modified ovary/ seed dispersal
-Present in SOME angiosperms
Importance of land plants adapting UV protection -Correct Answer ✔--Flavonoid
pigments that help protect against intense sunlight
-Adaption is present in all land plants
Importance of land plants adapting retention of zygote on parent -Correct Answer ✔--
Provides protection and nourishment for zygote
-Adaption is present in all land plants
Importance of land plants adapting ovaries -Correct Answer ✔--Provides protection for
the gametes
-Present in all angiosperms
What are the effects of reproductive isolation on the evolution of new species? -Correct
Answer ✔--There would be no interbreeding or fertile offspring
-Organisms would be different species if they are reproductively isolated from each
other
BIO 148
