bio 2 UC dr mosley final

Suppose seedlings of a plant emit a chemical that reduces the growth of other individuals around them. This would most likely result in the plants having a _dispersion

pattern.

Regular

Which of the following is not typical of a K-strategy species?

Short life span

Which of the following statements is an example of a density-independent effect?

Drought kills seeding

Discrete subpopulations linked together by regular movement of individuals between them is called a (n)

Metapopulation

If the birth rate is 0.05 and the death rate is 0.02, the intrinsic rate of increase (assuming that there is no immigration or emigration)

0.03

Excluding Curves B and D, use the remaining survivorship curves in the figure to answer the following question. Which curve best describes survivorship in marine mollusks?

Curve E

. In the logistic population growth curve shown in the graph below, the rate of growth is greatest at which point?

Point C

In arthropods, locomotion is accomplished by muscles

Exoskeleton

A small group of mice were released on an island. The island previously had no mice on it, but had abundant food and no predators. After several years of growth, the size of the new island population stabilizes. However, at this point a hurricane drastically reduces the population. How would you describe the situation?

1. The new population size is a result of density-independent regulation.

The striated appearance of skeletal muscle is due to the

1. regular arrangement of filaments.

Which of the following statements about the molecular arrangement of actin and myosin in myofibrils is false?

1. Troponin forms the head of the myosin molecule.

salmon follows a scent trail upstream to find its way back to the stream where it hatched What type of sensory receptor cell would it use?

Chemoreceptors

Shown below is an electron micrograph of part of a myofibril from a relaxed muscle fiber.

Which of the labeled regions will NOT shorten when the muscle contracts?

Z line

When animals die, muscles stiffen in rigor mortis because

1. actin and myosin cannot separate without ATP.

What would happen to people exposed to a chemical warfare agent that blocked acetylcholine from binding to muscle receptors?

1. Action potentials would be continuously generated, causing convulsive muscle contractions.

1. Muscle contractions would be prevented, causing paralysis.

Compared to humans, dogs have a much more acute sense of smell due to the

1. greater density of their olfactory nerve endings.

The greatest intensity of perceived smell comes from the

1. odorant that binds to the most receptors.

The frequency at which a single neuron can

"fire" action potentials is limited by the

1. refractory period for the neuron's Na+ channel.

The middle ear converts

1. air pressure waves to fluid pressure waves

Hair cells in the vertebrate ear are responsible for transducing sound pressure waves. Ion channels in the hair cell membrane open when

The structure enabling depolarization to travel deep into the muscle fiber is the

T tubule

Sensory transduction of light in the vertebrate retina is accomplished by

Rods exposed to light will

1. depolarize due to the opening of sodium channels

1. hyperpolarize due to the closing of sodium channels

Neurons that transmit information from sensory cells to the central nervous system are part of the

1. peripheral nervous system.

Which of the following sensory receptors is correctly paired with its category?

hair cell

- mechanoreceptor

Calculation, contemplation, and cognition are human activities associated with increased activity in the

cerebrum

In the spinal cord, the gray matter contains the

, and the white matter contains the

1. cell bodies; axons

After eating a large meal, which nerves are most active in your digestive system?

I. Parasympathetic nerves

II. Somatic (motor) nerves

III. Sympathetic nerves

Only I

Neurons that transmit information from sensory cells to the central nervous system are part of the

1. peripheral nervous system.

The generation of action potentials in sensory neurons initiated by changes in pressure is an example of

sensory transduction.

When several IPSPs arrive at the axon hillock rapidly in sequence from a single dendritic location, hyperpolarizing the postsynaptic cell more and more and thus preventing an action potential, this is an

temporal summation

Select the correct sensory pathway in a reflex arc.

1. Sensory neuron; spinal cord; interneuron; motor neuron; muscle

Which of the following physiological control mechanisms is a response to a rise in body temperature?

1. Increased blood flow to the skin

Many people wake in the middle of the night and can find their way to the kitchen for a drink of water, all without turning on the lights.

Their memory of spatial relationships between pieces of furniture and doors is rooted in the

hippocampus.

A squirrel that metabolically maintains its internal temperature durilg the summer but hibernates during the winter is a(n)

heterotherm

The "motor unit" in vertebrate skeletal muscle refers to

1. one motor neuron and all of the muscle fibers on which it has synapses.

What would be the effect on muscle contraction if troponin were experimentally altered to no longer interact with tropomyosin, so the complex could no longer bind to actin?

Muscles could not relax after contraction.

When an action potential from a motor neuron arrives at the neuromuscular junction

(NMJ, a series of events occurs that leads to muscle contraction. Which of the following events will occur last (i.e., after all of the

Conformational change in troponin

What causes rigor mortis?

1. lack of ATP in dead tissue

Individuals of a population that are all born at the same time are known as a

Cohort

The study of factors that determine the size and structure of populations through time is called

1. demography

Pacific salmon grow, mate, and then reproduce once, a process known as spawning.

Soon after they spawn, these fish die. These salmon are considered

1. semelparous.

Which of the following is not typical of a K-strategy species?

1. Parental care

2. A long life span

3. A small number of offspring

In the figure below, which of the following survivorship curves implies that an animal may lay thousands of eggs, of which a regular number die each year on a logarithmic scale?

Curve B

3he dispersion pattern in which the presence of one individual increases the likelihood of another individual being nearby is

clumped

Density-dependent factors are population-regulating factors that

1. have effects that vary depending on population size.

Which of the following causes populations to shift most quickly from an exponential to a logistic population growth?

1. Competition for resources

If two species are close competitors, and one species is experimentally removed from the community, the remaining species would be expected to

1. expand its realized niche

A community and the nonliving factors with which it interacts is called a (n)

Ecosystem

Some birds follow moving swarms of army ants in the tropics. As the ants march along the forest floor hunting insects and small vertebrates, birds follow and pick off any insects or small vertebrates that fly or jump out of the way of the ants. This is an example of what kind of species interaction?

Commensalism

As their name suggests, stick insects ("walking sticks") strongly resemble sticks or twigs. The most specific term for this method of avoiding detection by predators is

Cryptic

Which one of the following animals would most likely be defined as a keystone species?

Sea otter

While traveling in Texas, you stumble across a snake with red, yellow, and black bands. You somehow remember that this could be a poisonous coral snake or a harmless milk snake, but you forget how to differentiate them because they both have similar colors and banding patterns. You wisely decide not to pick up the snake. What defense was successful in preventing you from grabbing the snake?

1. Batesian mimicry

In deep water, which of the following abiotic factors would most limit productivity?

Light availability

Organisms that are most likely to tolerate harsh conditions are found during

1. early primary succession.

Eurasia, two closely related species of rock nuthatches (small birds that forage for insects and spiders on bare, rocky ground) occur either separately, or in zones of sympatry.

Individuals of both species that exist in the former situation, with no interspecies competition, have bills that are similar in length.

But in their zone of sympatry in Iran, one species has a longer bill than it has elsewhereand the other species has a shorter bill. This is an example of

Character displacement

Photosynthetic organisms are unique to most ecosystems because they

1. use light energy to synthesize organic compounds.

Examine this food web for a particular terrestrial ecosystem. Species C is toxic to predators. Which species is most likely to benefit from being a mimic of C?

Species b

Why is net primary production (NPP) a

• more useful measurement to an ecosystem ecologist than gross primary production (GPP)?

1. NPP represents the stored chemical energy that is available to consumers in the ecosystem.

After looking at the figure below, what can be said about productivity in this ecosystem?

1. Between 80% and 90% of the energy is lost at the next highest trophic level.

Nitrogen fixation and denitrification are

1. processes that have opposite effects.

The organisms that live on the refuse of an ecosystem are called

detritivores.

Invasive plant species

1. are detrimental because they often outcompete native species for resources.

What is the biological significance of genetic diversity between populations?

1. Genes for traits conferring an advantage to local conditions make microevolution possible.

Overharvesting encourages extinction and is most likely to affect

large animals with low intrinsic reproductive

Talen

This is caused by excessive nutrient runoff into aquatic ecosystems.

1. Eutrophication

According to the figure below, what is occurring after 1985?

The population increasing

According to the figure below, what is the least likely explanation for the data after 1985

Emigration

The body fluids of an osmoconformer would be

with its

_ environment.

1. isoosmotic; saltwater

Birds that live in marine environments and thus lack access to fresh drinking wateR

1. drinks seawater and secrete excess ions mainly through their nasal salt glands.

The nitrogenous waste that requires the most energy to produce is

uric acid.

An excretory system that is partly based on the filtration of fluid under high hydrostatic pressure is the

1. kidneys of vertebrates.

Processing of filtrate in the proximal and distal tubules

1. maintains homeostasis of pH in body fluids.

Increased ADH secretion is likely after

Sweating and due dehydration, increased plasma osmolarity

Blood enters a nephron's vascular component by way of the

1. afferent arteriole.

is an excretory system

that actively transports uric acid and ions into blind tubules found in insects and most terrestrial arthropods.

Malpighian tubule

Which of the following is not a factor in the movement of water into tissues?

1. Active transport of water

The functional unit of the kidney is

nephron.

To prepare flight muscles for use on a cool morning, hawkmoths

1. rapidly contract and relax these muscles to generate metabolic warmth.

Panting by an overheated dog achieves cooling by

1. evaporation.

Most biological Qio values are between and

2;3

Mammals and birds eat more often than reptiles. Which of the following traits shared by

27

mammals and birds best explains this habit?

Endothermy

Which of the following is the

thermoregulatory response of the hypothalamus to a rise in temperature?

1. Dilation of blood vessels in the skin.

A woman standing and watching the stars on a cool, calm night will lose most of her body heat by

Radiation

In mammals, most gas exchange between the atmosphere and the pulmonary blood occurs in the

alveoli.

The body's automatic tendency to maintain a constant and optimal internal environment is termed

Homeostasis

The thin horizontal arrows in the figure below show that the

1. warmer arterial blood transfers heat to the A cooler venous blood

Sponges, cnidarians, and flatworms lack a specialized gas exchange surface because

1. nearly all of their cells are in direct contact with the external environment.

Air rushes into the lungs of humans during inhalation because

1. the rib muscles and diaphragm contract, increasing the lung volume.

increase from pH 7.2 to pH 7.4 around hemoglobin causes

1. an increase in the binding affinity of hemoglobin to oxygen molecules.

The largest proportion of CO, carried by the blood is in the form of

1. bicarbonate ions (HCO,) carried in the plasma.

In the evolution of the vertebrate circulatory system, a transitional step led to separate pulmonary and systemic circuits. This step can be observed in

Lungfish

The diversity among antibodies occurs Mainly through

DNA changes

Acidity in human sweat is an example of

Innate immunity

Interactions between macrophages and lymphocytes are coordinated by

MHC proteins.

The activation of helper T cells is likely

1. when an antigen is displayed by a dendritic cell.

Among the last line of defenses against prolonged exposure to an extracellular pathogen is

1. antibody production by plasma cells.

When a T cell is activated by an antigen, it will most likely

proliferate.

Which of the following statements about natural killer cells is false?

1. They release cytokines.