Bio 360 - Exam 2

Animals exchange heat within environments by which of the following mechanisms?

1. Evaporation 2. Convection 3. Thermal radiation 4. Conduction

In the lives of animals, the significance of temperature includes.

1. It affects rate of energy expenditures and food intake 2. It is derterminant of species ranges 3. It affects properties of ecosystems 4. It is one of the largest determinants of metabolic rate 5. It affects proteins and tissues perform

Which of the following statements about homeoviscous adaptation are true?

1. It is evidence for hoe ectotherms/poikilotherms respond to ambient temperatures on the evolutionary time frame 2. It is a form of molecular specialization 3. It is the maintenance of relatively constant membrane fluidity regardless of tissue temperature

Compare the oxygen equilibrium curves of 11 species using curves that display oxygen concentration on the Y axis. What do the differenced in curve height indicate?

1. Species with higher curve maximums are better adapted to oxygen limitation because they can store more oxygen in their blood. 2. Species with higher curve maximums have larger amounts of respiratory pigment in circulation. 3. Species with higher curve maximums exhibit greater maximum amounts of oxygen that can be transported by the blood.

Properties of respiratory pigments can vary...

1. Temporally, whereby some forms are expressed only during specific developmental stages. 2. Depending on the number of subunits 3. With environmental conditions 4. As a function of body size across closely related species. 5. Spatially, whereby different forms are expressed in different body tissues.

Two forms (homologs) of the same enzyme expressed in different fish species exhibit substantial differences in their sensitivity to temperature changes such that one only functions maximally at 5C (narrow range form) and the other functions maximally across a 25C range (wide range form). What is the potential adaptive significance of this difference?

1. The fish expressing the wide range form will be more likely to survive and thrive when climate change increases water temperatures 2. If temperatures exceed 5C, the fish with the narrow range form will likely exhibit impairment of the enzymes's function 3. The fish expressing the narrow range form is adapted to function particularly well in an environment with a consistent water temperature of 5C

Antarctic ice fish are able to thrive without hemoglobin or any other respiratory pigment, because...

1. The live in cold water in which the solubility of oxygen is high 2. They have large hearts relative to their body 3. They have a relatively fast circulation.

In ___________, there is no separation of oxygenated and deoxygenated

4-chamber heart

In a healthy human at rest, what is the approximate O2 saturation of venous blood as it is leaving the tissues?

75%

A respiratory pigment that requires a relatively low O2 partial pressure for loading has ____________ affinity for O2.

A high

Which of the following statements about an oxygen equilibrium curve is false?

A hyperbolic curve shows that a greater proportion of oxygen is unloaded at higher oxygen partial pressure.

Based on your answer to the previous question, the result provide evidence that the fish has

A venous reserve

The reason why a trait is an asset to an animal is called its...

Adaptive significance

The springing seeds of lizards

Are often well-correlated with average body temperature of the species in nature

According the the figure below, which of the statements below is more accurate?

As swimming speed increases, the arterial blood remains nearly saturated while the venous blood decreases in saturation.

Which of the following statements about an animal's body temperature is true?

Body temperature will remain constant when heat gain is equal to heat loss

A decrease in pH, which can be caused by an increase in carbon dioxide reduces the affinity of hemoglobin for O2 and is called the __________ affect.

Bohr

A homeotherm is an animal that

Can regulate its body temperature by physiological means

The _________ circulatory system of squids and octopuses consists of ___________

Closed; two branchial hearts

The venous O2 partial pressure below which aerobic catabolism becomes impaired is known as the

Critical venous O2 partial pressure

The affinity of hemoglobin for O2 increases with

Decreasing temperature

Most animals are

Ecotherms/poikilothersms

All animals have a heart

False

An ectotherm/poikilotherm does not generate heat metabolically.

False

What happens to the blood flow rate as blood pressure increases?

Flow rate increases

What happens to the blood flow rate as viscosity increases?

Flow rate stays the same

Which chemical category of respiratory pigment is most widespread ?

Hemoglobin

Behavioral thermoregulation depends on __________ of the thermal environment and __________ with the environment

Heterogeneity: preferential selection of particular sites

Octopus and squid meet the increased demand for O2 at the tissues during intense exercise by

Increasing circulation rate

Which of the following statements about myoglobin is true?

It is a single subunit respiratory pigment found in muscle cells.

Hemocyanins occur in which of the following animal groups?

Molluscs & arthropods

Which of the following is not a chemical category of respiratory pigment?

Myoglobins

The hearts of crustaceans are neurogenic, meaning that

Neurons control the inherent pace of the heart

During exercise, oxygen partial pressure of the blood decreases and unfolding of oxygen from a respiratory pigment to the tissues in need...

Occurs more readily

The most important factor modifying flow in blood vessels is the diameter

Of the vessell

In acquatic ectotherms/poikilotherms, the most likely reason for impairment of function at elevated water temperature

Oxygen limitation

Depending on the animal, blood can appear...

Red, violet, green, clear, blue

In ecotherms/poikilotherms, the relationship between ambient temperature and metabolic rate is

Roughly exponential

Which of the following groups of animals have closed circulatory systems?

Squid and octopus, mammals, teleost fish, birds

Besides temperature, the factor that is important for conduction, convection and thermal radiation

Surface area

According to the Poiscuille equation, which of the following does not directly affect the flow rate?

Temperature of the tube

In the fish that have an air-breathing organ (ABO),

The blood leaving the ABO mixing with systemic and venous blood

The root effect applies to which of the following physiological mechanisms?

The forced unloading of oxygen to specific regions of the body.

The hearts of vertebrates are myogenic meaning that

The impulses to contract originates within the muscle tissue

Which of the following statements about respiratory pigments is false?

They are absolutely required for oxygen transport throughout an animal.

Which of the characteristics distinguishes respiratory pigments from enzymes?

They do not alter their primary ligand

Shattering assumptions that ectotherms.poikiotherms cannot use the metabolic production of heat to thermoregulate, researchers recently reported seasonal reproductive endothermy in lizards.

True

Some homeotherms exhibit temporal heterothermy, or sexual abandonment of thermoregulation

True

The eye lens of Antartic toothfish can be held at -2 degrees C for up to 30 years and maintain it clarity, or function

True

Without adaptive responses to survive freezing conditions, what would happen to the cells of ecththerms/poikilotherms?

Water would freeze first on the outside of the cell, osmosis would draw unfrozen extracellular water out, cells would shrink and die