BSCI207 Exam 3 CC & GAE

Pick the correct answer (bulk flow or diffusion) to complete the sentence describing these steps:

Animals fulfill their oxygen needs by having oxygen move from outside the body into the lungs by ________, by ________ into the blood stream, by _________ through the blood stream to an organ in the body, and by ___________ from the blood into the cells of that tissue.

bulk flow, diffusion, bulk flow, diffusion

Gas exchange systems utilize diffusion and the diffusion rate can be described by Fick's law: dV/dt = −DA (ΔPg/Δx)

In trying to maximize the diffusion rate, what aspects of the system, as specified by Fick's law, may require some design compromise, i.e. which terms might not be as big as they could be because they might cause organismal damage?

-the surface area across which oxygen diffuses

-the diffusion distance (tissue thickness)

-the difference in pressure across diffusive thickness

Some of the challenges for gas exchange in single celled organisms that are aquatic include

the concentration of oxygen in the aquatic environment

Match the aspect of organismal diversity on the left to how it contributes to evolution of gas exchange systems.

Phylogeny

constraining what genes are available to code for key structures and pigments

Match the aspect of organismal diversity on the left to how it contributes to evolution of gas exchange systems.

Metabolic Rate

Affecting amount of gas needed by the organism

Match the aspect of organismal diversity on the left to how it contributes to evolution of gas exchange systems.

Scaling

affecting surface area available to supply the volume of the organisms body

Match the aspect of organismal diversity on the left to how it contributes to evolution of gas exchange systems.

Medium

affecting amount of oxygen available to the organism

What is the most important role of stomates in supplying key aspects to a plant gas exchange system?

they provide a regulated pathway for CO2 getting into the leaves

Single celled organisms always rely on diffusion for gas exchange. When multicellular organism rely on diffusion, what variables are affected such that diffusion is maximized in those organisms?

-the animal evolves to limit its thickness

-the animal evolves to reduce its metabolic needs

Crabs have to function both on land and in the water. They use gills in both environments. What structural modifications have evolved to enable the gills to function in both environments?

some internal structure to keep gills from collapsing in air

What type of organism can successfully utilize a trachael system for gas exchange?

-a terrestrial organism

-a small organism

Cephalochordates like the lancelet have "gills". What are they used for?

feeding

Vertebrates evolved a two pump system for ventilation and circulation. Why did they evolve two pumps, i.e. what is/are the advantages?

To minimize the distances over which diffusion needs to occur

To maximize the gradients across the diffusion membranes

For a series of pill bugs of different sizes, if you were to plot volume (y axis) versus cross sectional area (x axis) on a log-log plot, the slope would be:

3/2 if the bugs were isometric

For an isometric series of forms, length will be a function of mass (or volume) to the what power?

1/3

A human baby's head seems really big compared to an adult. Which of the following is the most accurate explanation for why that is?

The baby's head does actually grow substantially, but it does so more slowly than the body as a whole. This is negative allometry.

T/F: Growth of different body parts can show different allometric relationships depending on the actual comparison. The head versus the body can show negative allometry while the body versus the head can show positive allometry.

true

Extracting oxygen from the air is easier than from water in many ways. What are features that makes oxygen uptake easier in air?

-relative oxygen concentration in air is higher

-relative viscosity of air is lower

-relative density of air is lower

We say that amphioxus has pharyngeal "gill" slits. Why is "gill" in quotations?

the gill does not perform the normal breathing function of a gill

Which of the following steps are key to the two phase pumping of water over a fish's gills?

-opening the buccal cavity while the opercular cavity is closed off

-closing the buccal cavity while the opercular cavity is opened

Why is counter-current exchange better than co-current exchange for oxygen uptake?

the final blood oxygen concentration is higher

What was one of the first key traits that evolved to make a vertebrate gas exchange organ?

the gills with interior blood vessels in lamella

What makes a mammalian lung less ideal than a bird lung?

-the mammalian lung has bidirectional flow

-the mammalian lung has uniform pool gas exchange

A lungfish has both gills and lungs. What direction flow do the gills utilize?

unidirectional

A lungfish has both gills and lungs. What direction flow do the lungs utilize?

bidirectional

A lungfish has both gills and lungs. What kind of pressure do the lungs utilize?

positive pressure

What type of breathing does a bird have?

negative pressure breathing

What type of breathing does a bony fish have?

positive pressure breathing

What type of breathing does a mammal have?

negative pressure breathing

What type of breathing does a reptile have

negative pressure breathing

The system components of a circulatory system include an energy source, a pump, ductwork, regulators, valves and fluids. Match the animal component on the left with the corresponding component in plants.

Pacemaker

Heart

Blood

Blood Vessels

Pacemaker- stomates

heart- water potential

blood- water

blood vessels- xylem

Which of the physical processes that are part of water circulation in plants contributes the most to the water potential and hence water movement?

transpiration

Water moves to a ________ solute concentration.

higher

water moves to ________ pressure.

lower

Which path in the root system has to deal with crossing the Casparian strip?

the apoplastic route

Match the organism with the style of circulatory system they utilize.

oak tree

grasshopper

frog

sponge

annelid worm

oak tree- flow through

grasshopper- "open" system

frog- closed system

sponge- flow through

annelid worm-closed system

We spent a lot of time comparing the circulatory systems of plants like a tree and animals like a giraffe. We concluded that trees have a _____________ pump that drives a _________ flow rate as a result of the _______________ xylem. Conversely, a giraffe has a ______________ pump that drives a ________ flow rate as a result of the _________________ blood vessels.

high pressure

low

high resistant

low pressure

high

low resistant

Initially, plaque build up in arteries will only occlude a small fraction of the flow. If the artery diameter is only 90% of normal, how much will the flow rate be compared to normal?

65%

In a mammlian circulatory system, why do the systolic and diastolic pressures differ?

the pressure is different when the ventricles constrict and when they relax

What are the challenges of the circulatory system found in fishes?

-there is pressure drop as the blood flows through both the gills and the systemic capillary beds

-the low pressure difference in the systemic systems means a low O2 delivery rate

In what system does blood flow go through the heart twice?

lung system

In what system does blood flow go through the ductus arteriolus?

gill system

in what system does blood flow go through arterioles not attached to gills?

lung system

In what system does blood flow through the systemic system?

Both lung and gill systems

Circulatory system of a goldfish

single circulation

one atrium

one ventricle

Circulatory system of a frog

double circulation

2 atria

one ventricle

Circulatory system of a parakeet

divided circulation

2 atria

2 ventricles

Circulatory system of a monitor lizard

double circulation

2 atria

1 ventricle with partial septum

In the mammalian circulatory system, where is pressure the highest?

systemic arteries

In the mammalian circulatory system, where is velocity the highest?

systemic arteries

In the mammalian circulatory system, where is resistance the highest?

systemic capillaries

In the mammalian circulatory system, where is velocity the lowest?

systemic capillaries

In the mammalian circulatory system, where is flow rate the greatest?

all are equal

If the Henry's law coefficient for oxygen is 1.3 millimoles/ 1 atm and the partial pressure in the lung is 100 mm Hg, what is the solubility of oxygen just in the blood plasma (the liquid part of the blood) given in millimolar units (millimoles per liter)?

0.17

Consider the locations in the body's circulatory system. The partial pressure of oxygen is indicated with color where red means high oxygen partial pressure and blue means low. In which location does the oxygen partial pressure in the blood decrease the most?

body tissue

Transport proteins including channels, transporters and pumps occur

in bacteria and archaea as well as in many copies in eukaryotes

Molecules that are large or charged require a protein to facilitate their movement across a membrane. This transport can differ depending on the characteristics of the moving molecule and will vary as to the amount of energy required and the speed with which the molecules can move. Molecules that move against their concentration gradient require _____________________ , and result in slow movement. Ions that move down their concentration gradient require ____________________ and move quite quickly fast. Large molecules moving down their concentration gradient require __________________ and move with intermediate speed.

a pump and an input of energy

channels that require no energy input

transporters that require no energy input

What are some of the uses of proton pumps and the resulting proton gradients in plants?

-they provide protons for cation exchange to free cations from soil particles

-they provide movement of cations against a concentration gradient

-they provide movement of anions against an electrochemical gradient

-they provide cotransport of sugars against concentration gradients

Order these key steps in non-vertebrate animal digestion ?

1) Phagocytosis of food particles

2) Fusion of food vacuoles with lysosomes

3) Digestion with hydrolytic enzymes in lysosomes

4) Nutrient transport using H+ pumps and transporters

4231

chicken beak function

capture prey

chicken crop function

store food

chicken gizzard function

mechanical and chemical digestion

chicken intestine function

digestion and absorption

chicken anus function

elimination

In the vertebrate digestive system, select the locations where proteins are digested

stomach

small intestine

What is the key insight behind the benefit of oral hydration therapy for curing diarhea?

Salt and sugar are needed to reduce dehydration

Which of the following processes require energy (are energetically unfavorable)?

active transport

True or False? "Water molecules can easily and rapidly diffuse through cells' plasma membranes, without a transport protein to help them."

False

If a solute is more dilute within the gut than it is inside the cells lining the gut, which of the following options will allow import of this solute by the gut cells for use by the body?

active transport (pump or a pump-coupled channel)

True or False? "The only way to reveal the existence of channels that allow facilitated diffusion is via electron microscopy of gut cell plasma membranes."

False

When a fish is in fresh water, the fish is

hyperosmotic

Osmolarity includes

all solutes

Organisms that need to maintain turgor pressure..

should be hyper osmotic compared to the environment

Which of the following are part of maintaining water balance in a paramecium?

-having K+ passively diffuse into contractile vacuoles

-cotransporting Cl- into contractile vacuoles

-having water enter the contracticle vaculoles by osmosis

A crab living in an estuary is essentially an osmoregulator. Match the action on the left with the correct condition on the right:

-gills take in water by osmosis

-urine is concentrated and in small amount

-crab consumes water and salt from food

-skin loses water by osmosis

-low tide

-high tide

-either tide

-high tide

What helps sea birds like an albatross osmoregulate?

-Sending out waste as a thick paste of uric acid

-drinking water and eating foods

-excreting salt through the nasal salt gland

Which organisms have the easiest time excreting their waste, without an excretory organ?

ionoconformers

In the shark rectal gland, which is the key initiating step?

Setting up a Na+ electrochemical gradient

Why don't insects with Malpigian tubules have a urinary system?

They don't have a closed circulatory system

The layers of tissue in the kidney vary in their osmolality of solute in the tissue. Arrange the three layers from low to high osmolality below:

-outer medulla

-cortex

-inner medula

cortex < outer medulla < inner medulla

True/False: Reabsorption of water into the capillaries is primarily due to active transport.

False

What is present in the filtrate that will enter the nephron?

glucose, H2O, salts, urea (large proteins cannot enter)

Which of these processes require ATP?

Salt excretion by saltwater fish

Salt excretion by freshwater fish

Salt excretion in inner medulla of kidney

Salt excretion in outer medulla

Salt excretion by saltwater fish

Salt excretion in outer medulla

Radiation

Light absorbed from the sun

Evaporation

Loss of water to the air

Conduction

Flow of heat to the substrate

Convection

Flow of heat to the surrounding medium

Which type(s) of energy can contribute to either gain or loss of heat, depending on the situation?

Conduction

Convection

Homeotherm

Body temperature remains constant

Poikilotherm

Body temperature varies with the environment

Endotherm

Body produces heat internally

Ectotherm

Body gathers heat from the surroundings

Match the different variables for diffusion on the left with the analogous variables for conductive heat transfer on the right.

concentration gradient

diffusive cross sectional area

diffusion coefficient

diffusion rate

-temperature gradient

-thermal cross sectional area

-thermal conductivity coefficient

-Heat transfer rate

Match the analogous term for heat conduction on the left with that for heat convection on the right.

thermal conductivity coefficient, k

temperature gradient

thermal cross sectional area

conduction of heat through solid

-thermal convection coefficient, h

-temperature difference

-thermal surface area

-convection of heat to surrounding medium

Think about endotherms and how they can use metabolism to input heat to offset heat loss. As a result of this heat input, the conductive temperature gradient they can produce relative to their surroundings will depend on their volume and cross sectional area. Which of the following is true statement?

Since dT/dx scales with r, larger organisms can produce larger temperature gradients.

Match the biological feature on the left with an important regulator or feedback mechanism on the right.

breathing rate

need to drink

overheating

becoming chilled

-blood pH

-antidiuretic hormone

-vasodilation

-vasoconstriction

How does an insulating layer contribute to decreasing heat loss?

-decreases thermal conductivity coefficient

-decreases temperature gradient

How does an insulating layer contribute to decreasing heat loss?

-decreases thermal conductivity coefficient

-decreases temperature gradient by increasing layer thickness

Blood flow out to extremities are often set up so as to take advantage of counter current exchange. For an endotherm in a cold environment, this enables the extremity to be ______ than the body. Heat from the blood going out is _________ the blood coming back from the extremity.

cooler

transferred to