Bio HW?

Some bird bones are hollow rather than honeycombed. The hollow bones mostly contain air sacs. The replacement of bone marrow with air sacs is properly understood as an adaptation that ________. 1. reduces the weight of the bird 2. facilitates flight 3. eliminates the functions of bone marrow

1 and 2

What might be a consequence of global warming for fishes living in a pond?

As the planets warms, aquatic habitats such as a pond will contain less dissolved oxygen, reducing the ability of fishes to acquire oxygen for their respiratory needs.

How much more blood does the heart move in a minute when stimulated compared to at rest?

At rest, 5040 mL of blood is moved per minute. When the heart is stimulated, 30240 mL of blood is moved per minute. To calculate how much more blood is moved per minute during stimulation: 30240 - 5040 = 25200 mL

In what way does hemoglobin act as a buffer against changes in blood pH?

Hemoglobin binds some of the excess protons released by carbonic acid.

Which group has an open circulatory system?

Insects insects have an open circulatory system. However, their tracheal respiratory system is able to provide oxygen directly to the tissues as well.

Which feature is common to gills, lungs, and tracheae?

Large surface area All have a relatively large surface area for better gas exchange.

Some animals have no gills when young, but then develop gills that grow larger as the animal grows larger. What is the reason for this increase in gill size?

Relative to their volume, the young have more surface area across which they can transport all the oxygen they need.

Calculate the volume of blood moved per minute by a heart that has been stimulated by epinephine.

The heart rate at rest is 72 beats per minute. Stimulation with epinephrine doubles the heart rate to 144 beats per minute. The blood volume moved per beat at rest is 70 mL. Stimulation with epinephrine triples the volume moved per beat to 210 mL. The total volume moved per minute when the heart is stimulated is: 144 beats/1 min X 210 mL/1 min = 30240 mL/min

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

The lower partial pressure of oxygen in the atmosphere reduces the rate of diffusion of oxygen into your body. Differences in partial pressure of gases drive the rate of diffusion. Lower atmospheric pressure means lower oxygen partial pressure, reducing oxygen uptake.

Calculate the volume of blood moved per minute by a heart at rest.

The total volume of blood moved in one minute by a resting heart = the number of beats in a minute x the volume of blood moved per beat 72 beats/1 min X 70 beats/1 min = 5040 mL/min

What is the percent increase in blood flow due to stimulation?

To find the percent increase, compare the increase to the value at rest: 25200/5040 = 5 = 5.00 = 500% A 500% increase means that 5 times more blood is pumped when the heart is stimulated by epinephrine than when it is at rest.

Which of the following is a disadvantage of external gills? a. Vulnerable to predation b. Passive ventilation c. In direct contact with water d. Protected from mechanical damage

Vulnerable to predation

By picking up hydrogen ions, hemoglobin prevents the blood from becoming too _____.

acidic If not carried by hemoglobin, hydrogen ions would reduce the pH, or increase the acidity, of the blood.

Air-breathing insects carry out gas exchange _____.

across the finest branches of the trachea and cell membranes

Most carbon dioxide is carried from the body tissues to the lungs _____.

as bicarbonate ions (HCO3 -) Most carbon dioxide released from body tissues combines with water to form carbonic acid, which then breaks up into hydrogen and bicarbonate ions.

In the blood most of the oxygen that will be used in cellular respiration is carried from the lungs to the body tissues _____.

combined with hemoglobin

Most of the carbon dioxide produced by humans is ________.

converted to bicarbonate ions by carbonic anhydrase, an enzyme in red blood cells

If other factors are equal, which of the following environments would have the highest level of dissolved oxygen?

cool freshwater at low elevation

Countercurrent exchange in the fish gill helps to maximize ________.

diffusion & extraction of oxygen from the water

Under identical atmospheric conditions, freshwater _____.

has more oxygen than seawater

Fick's law of diffusion describes the factors that influence the diffusion of respiratory gases across biological membranes like gills and lungs. Diffusion rate = k × A × (P2 P1)/D. Natural selection is LEAST likely to act upon which variable in Fick's law?

k

The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in _____.

pH

Together, the respiratory and circulatory systems function to ____________.

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

During athletic training, the oxygen−hemoglobin dissociation curve

shifts to the right, unloading more oxygen to tissues.

Which of the following respiratory systems is NOT closely associated with the blood supply? a. the tracheal system of an insect b. the lungs of a vertebrate c. the skin of an earthworm d. the gills of a fish

the tracheal system of an insect

Which of the following events would be predicted by the Bohr shift effect as the amount of carbon dioxide released from your tissues into the blood capillaries increases? The amount of oxygen in _____. a. venous blood would decrease b. venous blood would increase c. arterial blood would decrease d. arterial blood would increase

venous blood would decrease

Countercurrent exchange is evident in the flow of _____.

water across the gills of a fish and the blood within those gills