BIOL 1260 Exam 2 Prelecture and Homework Questions

Because cell walls consist of a cross-linked network of long filaments embedded in a stiff surrounding material, they can be called _____.

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a.) spongy bone        

b.) spot-welded sheets        

c.) plasma membranes        

d.) fiber composites        

d.) fiber composites

The most abundant protein found in the extracellular matrix of animal cells is _____.

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a.) collagen

b.) cellulose

c.) hemoglobin

d.) pectin

a.) collagen

The type of cell–cell attachment that resembles quilting, with proteins acting as stitches, is _____.

  

a.) desmosomes

b.) selective adhesions

c.) gap junctions

d.) tight junctions

d.) tight junctions

What role do plasmodesmata play in plant cells?

 

a.) They prevent the plant cell from losing water in desert conditions.

b.) They serve as communication portals between neighboring plant cells, allowing the passage of small molecules between the two cells.

c.) They serve as sites of protein production in the cell.

d.) They allow the plant cell to withstand extreme temperatures.

b.) They serve as communication portals between neighboring plant cells, allowing the passage of small molecules between the two cells.

Which tissue type in your body typically shows regeneration?

  

a.) Epithelial tissues

b.) Skeletal muscle

c.) Cardiac muscle

d.) Nervous tissues

a.) Epithelial tissues

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Epithelial tissues have cells that actively undergo mitosis and cytokinesis to replace those lost on their apical surface.

If a mouse has a mass-specific metabolic rate that is 10 times higher than an elephant, what does that tell you about food needs of a mouse?

  

a.) Mice sleep more so require less food.

b.) Relative to body mass, mice will eat much more food per day.

c.) Relative to body mass, mice will eat less food than elephants.

d.) Mice and elephants eat the same amount of food when you account for body size.

b.) Relative to body mass, mice will eat much more food per day.

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The high metabolic rate of mice will require relatively more effort to find food.

Why do salmon rely increasingly on gills for respiration as they get larger?

  

a.) Gills only work in small fishes. 

b.) Salmon live in oxygen-rich water and therefore require gills for respiration.

c.) The skin of salmon becomes increasing impermeable to oxygen.

d.) As the surface-area-to-volume ratio drops with growth, salmon require an adaptation with increased surface area to permit them to acquire adequate oxygen from the environment.

d.) As the surface-area-to-volume ratio drops with growth, salmon require an adaptation with increased surface area to permit them to acquire adequate oxygen from the environment.

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Gills are needed to compensate for increasing size in fishes.

Both root system and shoot system in plants are involved in shared functions as well as distinct functions. Which of the following defines a function common to both roots and shoots?

  

a.) Absorption of mineral nutrients

b.) Harvesting resources from the environment

c.) Photosynthesis

d.) Anchoring the plant

b.) Harvesting resources from the environment

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Shoots harvest CO2; roots harvest water and minerals.

What is meant by phenotypic plasticity in roots and shoots?

 

a.) The ability to harvest resources from the environment

b.) The amount of elongation growth in a growing season

c.) The nature of cell walls, allowing cells to expand and shrink when necessary

d.) The ability to modify form depending on environmental conditions

d.) The ability to modify form depending on environmental conditions

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Remember that phenotype refers to morphological appearance, while plasticity refers to variation in phenotype in varying environments.

The function of sieve-tube elements is to _____.

  

a.) transport water upward

b.) transport carbon dioxide into leaves

c.) transport water downward

d.) transport sugars throughout the plant

d.) transport sugars throughout the plant

 

Sugars are transported along a concentration gradient to many areas of the plant.

Water potential (the potential energy of water) at a given location is determined by _____.

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a.) the force of gravity on the water

b.) the presence or absence of cell walls

c.) physical pressure on water and the amount of solutes dissolved in it

d.) the nature of solutes dissolved in water

c.) physical pressure on water and the amount of solutes dissolved in it

How do plants that are adapted to dry and salty soils tolerate the low water potential in the environment?

  

a.) By wilting during daytime

b.) By increasing transpiration

c.) By keeping their stomata closed all the time

d.) By lowering the solute potential inside their cells

d.) By lowering the solute potential inside their cells

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Lowered solute potential will draw water into the cells.

What is the force behind the process known as "transpiration" in plants?

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a.) Cohesion-tension

b.) Water is absorbed into leaves through stomata.

c.) Carbon dioxide is absorbed through stomata.

d.) Water is absorbed into the roots through root hairs.

a.) Cohesion-tension

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The pull of water evaporating from the leaves, the resulting tension that pulls water from surrounding cells, and the cohesion of water molecules that pulls water up in xylem vessels is the force that moves water through plants.

When water moves from soil into the vascular tissues inside the root, it can take three possible pathways. Of these, the apoplastic route is _____.

  

a.) through plasmodesmata

b.) through aquaporins on the plasma membrane

c.) between cells and through cell walls

d.) by active diffusion across the plasma membrane

c.) between cells and through cell walls

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Water can move through the apoplast but must enter the symplast at the endodermis to enter the xylem.

When would you observe a positive root pressure?

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a.) During heavy transpiration

b.) During hot and sunny days

c.) During guttation

d.) When the water potential inside the root is very low

c.) During guttation

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Guttation is caused by water influx into the xylem from other root cells at night, creating root pressure and generating a positive pressure that forces fluid up the xylem.

The transport of a water column up a very tall tree can be explained by _____.

 

a.) cohesive and adhesive forces of the water column under evaporative tension and differences in pressure

b.) gravitational pull

c.) positive pressure in xylem that pushes water up

d.) root pressure that pushes water up

e.) cohesive and adhesive forces only

a.) cohesive and adhesive forces of the water column under evaporative tension and differences in pressure

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The pull of evaporation, combined with the cohesive tendency of water to form hydrogen bonds, moves water.

Which of the following plant organs may act as a source for translocation of sugars inside a plant?

  

a.) Mature leaves

b.) Young growing leaves

c.) Developing flowers

d.) Any non-green tissue

a.) Mature leaves

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Mature leaves photosynthesize, manufacturing sugars.

According to the pressure-flow hypothesis, what mechanism causes the movement of phloem sap from sources to sink tissues?

  

a.) Solute potential differences between source and sink

b.) Solute potential differences between source and sink

c.) Pressure potential differences between source and sink

d.) Transpirational pull from the leaves

c.) Pressure potential differences between source and sink

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These differences cause a flow of sugars in the phloem.

Imagine a plant without phloem. For sugars to move from one region of the plant to another, what must happen?

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a.) The sugars will passively move down a concentration gradient.

b.) The sugars would be actively transported from cell to cell.

c.) The sugars must be loaded into tracheids and vessel elements instead.

d.) It would be impossible for sugars to move.

b.) The sugars would be actively transported from cell to cell.

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ATP-mediated protein transport is still possible.

Root hairs absorb nutrients from soil against the nutrient concentration gradient. To achieve this, root hairs use _____.

  

a.) facilitated diffusion

b.) direct diffusion

c.) proton pumps

d.) osmosis

c.) proton pumps

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Proton pumps create an electrical gradient, which plants then use to attract cations.

Anions are repelled, not attracted, by the electric gradient established by the proton pumps. How do plants absorb anions?

  

a.) By diffusion

b.) By cotransport proteins

c.) By vacuoles

d.) By active transport proteins that require ATP

b.) By cotransport proteins

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Anions are brought in accompanying cations.

What is biological nitrogen fixation?

 

a.) The conversion of nitrogen gas into ammonia, nitrate, or nitrite by microbes

b.) The conversion of nitrogen gas into ammonium ions inside root cells

c.) The exclusion of excess nitrate ions from plant roots

d.) The absorption of nitrate ions by plant roots

a.) The conversion of nitrogen gas into ammonia, nitrate, or nitrite by microbes

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Only a few kinds of microbes are capable of this.

Legume plant roots are colonized by _____ to form root nodules.

  

a.) epiphytes

b.) ectomycorrhizae

c.) node factors

d.) rhizobia

d.) rhizobia

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These bacteria live in the nodules and fix nitrogen from the soil.

If a plant grows on another plant and depends on this plant for all its nutritional needs, including sugars, nutrients, and water, it can most specifically be called a(n) _____.

  

a.) symbiotic plant

b.) epiphytic plant

c.) parasitic plant

d.) infectious plant

 

c.) parasitic plant

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A parasite is an organism that obtains water and/or nutrients from another organism.

Carnivorous plants trap and digest insects to overcome _____.

  

a.) nitrogen deficiency in low-nitrogen soils

b.) excess digestive enzyme activity inside the cells

c.) lack of water in arid environments

d.) infectious diseases transmitted by insects

a.) nitrogen deficiency in low-nitrogen soils

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Due to low decomposition rates, nitrogen is in short supply in the wet environments where most carnivorous plants are found.

Which of these cell junctions form a barrier to the passage of materials?     

  

a.) tight junctions        

b.) keratin fibers        

c.) desmosomes (anchoring junctions)        

d.) plasmodesmata        

e.) gap (communicating) junctions       

a.) tight junctions        

The primary role of _____ is to bind animal cells together.     

  

a.) gap (communicating) junctions        

b.) tight junctions        

c.) desmosomes        

d.) the cytoskeleton        

e.) plasmodesmata        

c.) desmosomes

_____ aid in the coordination of the activities of adjacent animal cells.     

  

a.) Keratin fibers        

b.) Desmosomes        

c.) Gap (communicating) junctions        

d.) Tight junctions        

e.) Plasmodesmata        

c.) Gap (communicating) junctions    

Integrins are integral membrane proteins. They are often attached to _____. 

  

a.) the membranes of intracellular organelles

b.) the outside of the plasma membrane

c.) cytoskeletal proteins and proteins in the extracellular matrix

d.) glycogen molecules and other types of cellular inclusions

c.) cytoskeletal proteins and proteins in the extracellular matrix

H. V. Wilson worked with sponges to gain some insight into exactly what was responsible for holding adjacent cells together. He exposed two species of differently pigmented sponges to a chemical that disrupted the cell—cell interaction (cell junctions), and the cells of the sponges dissociated. Wilson then mixed the cells of the two species and removed the chemical that caused the cells to dissociate. Wilson found that the sponges reassembled into two separate species. The cells from one species did not interact or form associations with the cells of the other species. How do you explain the results of Wilson's experiments? 

 

a.) The two species of sponge had different enzymes that functioned in the reassembly process.

b.) The molecules responsible for cell—cell adhesion (cell junctions) were irreversibly destroyed during the experiment.

c.) The molecules responsible for cell—cell adhesion (cell junctions) differed between the two species of sponge.

d.) One cell functioned as the nucleus for each organism, thereby attracting only cells of the same pigment.

c.) The molecules responsible for cell—cell adhesion (cell junctions) differed between the two species of sponge.

Intercalated discs are cellcell junctions found between cardiac muscle cells. One feature of these intercalated discs is that they contain a large number of gap junctions, which means that ________. 

 

a.) water ions and small molecules can readily pass from one cardiac muscle cell to the next

b.) an extension of smooth endoplasmic reticulum goes through the gap junction, making it continuous from one cardiac muscle cell to the next

c.) RNA from one cardiac muscle cell can be transported into an adjacent cell through the gap junction

d.) cardiac cells can function independently when necessary

 

a.) water ions and small molecules can readily pass from one cardiac muscle cell to the next

Which of the following is an example of a connective tissue? 

  

a.) smooth muscles

b.) cuboidal epithelium

c.) blood

d.) nerves

e.) the surface of the skin

 

c.) blood

You are looking through a microscope at a slide of animal tissue and see a single layer of flat, closely packed cells that cover a surface. This specific tissue is most likely _____. 

  

a.) epithelial

b.) cardiac muscle of the heart

c.) a tendon

d.) adipose

e.) a neuron

a.) epithelial

Blood is a type of connective tissue because blood _____. 

  

a.) has an extensive extracellular matrix

b.) can be both liquid and solid

c.) has multiple cell types

d.) functions in transportation

a.) has an extensive extracellular matrix

The large surface area in the small intestine directly facilitates ________. 

  

a.) absorption

b.) filtration

c.) secretion

d.) elimination

e.) temperature regulation

a.) absorption

An elephant and a mouse are running in full sunlight, and both overheat by the same amount above their normal body temperatures. When they move into the shade and rest, which animal will cool down faster? 

 

a.) The elephant will because it has the higher surface-area-to-volume ratio.

b.) The elephant will because it has the lower surface-area-to-volume ratio.

c.) The mouse will because it has the higher surface-area-to-volume ratio.

d.) They will cool at the same rate because they overheated by the same amount.

e.) The mouse will because it has the lower surface-area-to-volume ratio.

c.) The mouse will because it has the higher surface-area-to-volume ratio.

The surface area of a plant's root system is substantially larger than the surface area of its shoot system. The extensive surface area of roots is an adaptation associated with ________. 

  

a.) the internal structure of the vascular tissue in roots

b.) the release of carbon dioxide generated by photosynthesis

c.) the fact that roots absorb materials while shoots do not

d.) the storage of nutrients within the root system

e.) contact with soil particles for mineral and water absorption

e.) contact with soil particles for mineral and water absorption

A general name for filter feeding in animals is ____________.

  

a.) fluid feeding

b.) mass feeding

c.) suspension feeding

d.) deposit feeding

c.) suspension feeding

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This form of feeding involves specialized adaptations for filtering water such as fans or gills.

Chemical digestion of carbohydrates and lipids begins in the ____________, while chemical digestion of proteins begins in the _____________.

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a.) large intestine; mouth        

b.) mouth; stomach        

c.) small intestine; stomach        

d.) stomach; mouth        

b.) mouth; stomach      

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Salivary amylase and lingual lipase attack carbohydrates and lipids in the mouth, while pepsin begins protein digestion in the stomach.

Which step in the production of stomach acid requires energy in the form of ATP?

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a.) Movement of chloride ions (Cl-) into the lumen of the stomach

b.) Conversion of water and carbon dioxide into carbonic acid

c.) Movement of protons (H+) in the lumen of the stomach

d.) Exchange of bicarbonate with chloride from the interstitial space

c.) Movement of protons (H+) in the lumen of the stomach

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Proton pumps use the energy of ATP to pump protons into the stomach.

In humans, most digestion occurs in what structure?

  

a.) Large intestine

b.) Stomach

c.) Pancreas

d.) Small intestine

d.) Small intestine

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This section of the digestive track receives digestive enzymes from the pancreas and bile from the liver (by way of the gall bladder).

Together, the respiratory and circulatory systems function to ____________.

 

a.) provide oxygen to your tissues and remove carbon dioxide from your body

b.) provide nitrogen to your tissues and remove carbon dioxide from your body

c.) provide carbon dioxide to your tissues and remove oxygen from your body

d.) provide oxygen to your tissues and remove nitrogen from your body

a.) provide oxygen to your tissues and remove carbon dioxide from your body

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Aerobically active tissues require oxygen to carry out metabolism and must get rid of the waste product, carbon dioxide.

Why is breathing more difficult at high altitudes, such as at the top of Mount Everest?

 

a.) At high altitudes, the air only contains nitrogen, so breathing is more difficult.

b.) The lower partial pressure of oxygen in the atmosphere reduces the rate of diffusion of oxygen into your body.

c.) The lower atmospheric pressure reduces the ability of the body to pump air into the body.

d.) Carbon dioxide will not diffuse out of your body at high altitude.

b.) The lower partial pressure of oxygen in the atmosphere reduces the rate of diffusion of oxygen into your body.

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Differences in partial pressure of gases drive the rate of diffusion. Lower atmospheric pressure means lower oxygen partial pressure, reducing oxygen uptake.

What is a common feature of fish gills and mammalian lungs?

 

a.) Both fish gills and mammalian lungs employ countercurrent flow for respiration.  

b.) Both fish gills and mammalian lungs have relatively high surface area.

c.) Both fish gills and mammalian lungs end in terminal alveoli.

d.) Both fishes and mammals get oxygen from an oxygen-rich medium.

b.) Both fish gills and mammalian lungs have relatively high surface area.

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Greater surface area permits higher rates of respiration.

A key aspect of cooperative binding by hemoglobin is that ___________.

 

a.) it allows for great binding of carbon dioxide and increases the amount of carbon dioxide that is carried out of the body

b.) it reduces the amount of oxygen provided during exercise

c.) it increases delivery of oxygen during periods of rest to save energy and reduce metabolism

**d.)** it permits rapid uptake of oxygen in the lungs and greater delivery of oxygen once blood reaches capillaries in the body's tissues

**d.)** it permits rapid uptake of oxygen in the lungs and greater delivery of oxygen once blood reaches capillaries in the body's tissues

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Cooperative binding is critical to the high rate of oxygen transport in the circulatory system.

What might be the function of the muscle contraction in the walls of veins?

  

a.) Muscle contraction closes the vein and prevents blood flow in the vein.

b.) Muscle contraction occurs during period of inactivity to allow the vein to reduce blood pressure.

**c.)** Muscle contraction reduces the volume of veins, increasing blood pressure and, thereby, increasing the velocity of blood flow.

d.) Muscle contraction allows mammals to bypass blood flow to their lungs during periods of breath holding.

**c.)** Muscle contraction reduces the volume of veins, increasing blood pressure and, thereby, increasing the velocity of blood flow.

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This is a key response when a person enters of period of intense physical activity.

Where is the velocity of blood flow the slowest in your body?

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a.) Capillaries

b.) Arteries

c.) Aorta

d.) Veins

a.) Capillaries

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The very high total cross-sectional area of capillaries means that blood flow there is very slow, providing opportunity for diffusion into and out of the blood.

Are cations attracted or repelled from the interior of a plant cell?

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a.) Attracted since the interior of the plant cell has a net negative charge

b.) Repelled since the interior of the plant cell has a net negative charge

c.) Attracted since the interior of the plant cell has a net positive charge

d.) Repelled since the interior of the plant cell has a net positive charge

a.) Attracted since the interior of the plant cell has a net negative charge

How would poisoning proton pumps impact anion uptake?

  

a.) It would decrease the uptake of anions by passive diffusion.

b.) It would decrease the uptake of anions via cotransport with protons.

c.) It would increase the uptake of anions via cotransport with protons.

d.) It would have no effect; most anions utilize ATP-driven pumps for uptake.

b.) It would decrease the uptake of anions via cotransport with protons.

In which environment do you least expect to find nitrogen-fixing bacteria?

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a.) Where nitrogen is plentiful, while other essential nutrients are rare

b.) Where nitrogen and other essential nutrients are rare

c.) Where nitrogen and other essential nutrients are plentiful

d.) Where nitrogen is rare, while other essential nutrients are plentiful

a.) Where nitrogen is plentiful, while other essential nutrients are rare

Mistletoe and bromeliads both grow on trees. What relationship does each have with the tree that supports them?

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a.) Mistletoe absorbs xylem from its tree, while bromeliads absorb water and nutrients from the rainwater and dust they collect.

b.) Bromeliads absorb xylem from its tree, while mistletoe absorbs water and nutrients from the rainwater and dust it collects.

c.) Both plants absorb xylem from their tree.

d.) Both plants absorb water and nutrients from the rainwater and dust they collect.

a.) Mistletoe absorbs xylem from its tree, while bromeliads absorb water and nutrients from the rainwater and dust they collect.

Why is the surface area of the small intestine so high compared to the stomach?

  

a.) To better eliminate waste

b.) To better remove pathogens

c.) To better digest food

d.) To better absorb nutrients

c.) To better digest food

d.) To better absorb nutrients

What would happen to someone treated with a drug that inhibited the release of bile salts? 

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a.) The person would lose weight.

b.) The person would gain weight.

c.) The person would become diabetic.

d.) The person would suffer atrophy in their muscles.

a.) The person would lose weight.

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Fats would not be broken down and absorbed into the epithelial cells of the small intestine.

Air rushes into the lungs of humans during inhalation because ________. 

  

a.) pulmonary muscles contract and pull on the outer surface of the lungs

b.) a positive respiratory pressure is created when the diaphragm relaxes

c.) the rib muscles and diaphragm contract, increasing the lung volume and decreasing the pressure within the lungs

d.) gas flows from a region of lower pressure to a region of higher pressure

e.) the volume of the alveoli increases as smooth muscles contract

c.) the rib muscles and diaphragm contract, increasing the lung volume and decreasing the pressure within the lungs