When sarcomeres contract, they generate force (tension). However, the amount of force
generated depends on the sarcomere length and the amount of thick and thin filament
overlap. Below is a figure that details the forcegenerating properties of a single
sarcomere. This figure was modified from a scientific paper by Al Gordon and
colleagues from 1966 and is a classic illustration of the relationship between sarcomere
length and force.
What portion of the graph would involve myosin forming cross-bridges and going
through power strokes?
A) from A to B
B) from D to B
C) from B to E
D) from A to E
The two main functions of the lymphatic system are
A) coagulating blood and fighting infections.
B) producing hormones that regulate the immune system and coagulating blood.
C) producing hormones that regulate the immune system and fighting infections.
D) returning tissue fluid to the circulatory system and fighting infections.
Which of the following is a likely consequence of thinning of the ozone layer?
A) increases in skin cancer
B) increases in escape of heat from Earth
C) global warming
D) decreases in flying insect populations
When a tetraploid flower pollinates a diploid flower of the parental species, the
resulting offspring will be
A) pentaploid and sterile.
B) diploid and fertile.
C) triploid and fertile.
D) triploid and sterile.
Which of the following describes a complete defense system?
A) antibodies of the adaptive humoral immune response and interferons
B) antibodies of the adaptive humoral immune response and components of innate
immunity
C) phagocytosis only
D) complement system only
Which of the following statements regarding nucleotides is false?
A) Nucleotides contain lipids.
B) Nucleotides contain sugar molecules.
C) Nucleotides can be linked together to form nucleic acids.
D) Nucleotides contain nitrogenous bases.
Our biological clock, which regulates the sleep-wake cycle, is housed within the
A) cerebrum.
B) hypothalamus.
C) cerebellum.
D) brainstem.
Two populations of organisms belong to the same biological species when they
A) cannot mate with each other because mating occurs at different times.
B) use different types of behaviors or physical features to attract mates.
C) have anatomical features that make it difficult for organisms from the two
populations to mate with one another.
D) encounter each other, mate, and produce viable, fertile offspring under natural
conditions.
In general, plant dermal tissues are found
A) at the outer surface of a plant.
B) near the center of the plant stems and roots.
C) lining the vascular tissue.
D) throughout the plant body.
During muscle contraction,
A) only the thin filaments shorten.
B) only the sarcomere shortens.
C) only the thick filaments shorten.
D) both the thick filaments and the sarcomere shorten.
A mature ovary, specialized as a vessel that houses and protects seeds, is a
A) fruit.
B) ovule.
C) cotyledon.
D) seed coat.
Your first big biology exam is coming up in a few days, and in order to prepare for
late-night study sessions, you buy a box of Yummies, a delicious type of snack cake.
After checking out the nutrition facts label on the side of the box, you discover that a
single Yummie cake contains 4.5 grams of total fat, 27 grams of carbohydrate, 0 grams
of fiber, and 1 gram of protein.
The pH of the stomach is extremely acidic (~ pH 2). If you ate a Yummie cake, what do
you think would happen to the protein that you ingested as it passes through the
stomach?
A) The protein would become denatured due to the acidic environment.
B) The protein would form longer proteins via dehydration reactions.
C) The protein would speed up digestion because it is an enzyme.
D) The protein would get broken down via dehydration reactions.
Which of the following is the first distinctively hominin trait to appear in the fossil
record?
A) sophisticated stone tools
B) increased brain size
C) upright walking (bipedalism)
D) a very long period of parental care
The function of the sphincter between the stomach and small intestine is to
A) retain chyme in the stomach until pepsin digestion is complete.
B) periodically release chyme into the small intestine in squirts.
C) release bile into the duodenum when chyme is present.
D) release pancreatic secretions into the duodenum when chyme is present.
Which of these models is best studied through a systems approach?
A) model of O2/CO2 exchange in a leaf
B) model of arrangements of atoms in a molecule
C) model of the biogeochemical cycling of nutrients
D) model of skin color inheritance
A regional assemblage of interacting ecosystems is a
A) biome.
B) landscape.
C) corridor.
D) hot spot.
You are looking at a sample of epithelial tissue under a microscope. What would you
look for to determine the type of epithelium you are viewing?
A) the number of cell layers
B) the shape of the cells
C) the color of the cells
D) the number of cell layers and the shape of the cells
What is the minimum change in the membrane’s voltage that must occur to generate the
action potential?
A) +20
B) +40
C) +70
D) +120
You are setting up a PCR reaction and add a primer for one end of the target sequence,
but you forget to add the primer for the other end of the target sequence. If you added
the other necessary components, what do you expect to observe after running the PCR
reaction for 40 cycles?
A) The PCR reaction will produce billions of copies of the target DNA.
B) The PCR reaction will produce millions of copies of the target DNA.
C) The PCR reaction will produce one copy of the target DNA.
D) The PCR reaction will produce zero copies of the target DNA.
When humans are cold, they often shiver. Shivering increases their ________, thereby
warming their bodies.
A) metabolic heat production
B) insulation
C) circulatory adaptation
D) evaporative cooling
A hydrogen atom has one electron. How many covalent bonds can hydrogen form?
A) one
B) two
C) four
D) none
The frequency of homozygous dominant individuals in a population that is in
Hardy-Weinberg equilibrium is equal to
A) q orp.
B) p2.
C) 2pq.
D) 2p.
Why must water that has moved to the interstitial fluid in the medulla be quickly
removed from the interstitial fluid?
A) to prevent dilution of urine
B) to prevent destruction of the concentration gradient necessary for water reabsorption
C) to equilibrate the concentration of solutes in the cortex and medulla
D) to maintain an environment for transport of nutrients
How many chromosomes are there in a maize embryo cell nucleus as compared to a
maize endosperm cell nucleus?
A) half as many
B) two-thirds as many
C) the same number
D) twice as many
Kudzu is a fast-growing vine that was introduced to the United States in 1876 as a
fragrant, ornamental plant and was later used as a source of erosion control. Kudzu
grows especially well in the warm, humid climate of the Southeastern United States. In
fact, it grows so well that it outgrows and can kill off less successful native plants; it
can also kill off areas of forest because it prevents forest tress from receiving sunlight.
Kudzu can best be described as
A) a keystone species.
B) an invasive species.
C) a source of primary production.
D) an abiotic reservoir.
Which of the following statements regarding the cell cycle control system is false?
A) The cell cycle control system receives messages from outside the cell that influence
cell division.
B) The cell cycle control system triggers and controls major events in the cell cycle.
C) The cell cycle control system includes three key checkpoints to complete a cell
cycle.
D) The cell cycle control system operates independently of the growth factors.
Biosphere II is a huge dome-covered self-contained structure located outside Tucson,
Arizona. It was built to try to duplicate Earth’s biosphere and ecosystems in miniature
and to use the information gained from the experiment to help design similar habitats
on the Moon and Mars. The habitat contained small versions of many of Earth’s
ecosystems, including an ocean with a coral reef, mangrove wetlands, a grassland, a
desert, an agricultural system, and a human habitat. Eight men and women were sealed
inside the habitat for a proposed two-year stay. The air, water, and food for the
“biospherians” all came from inside the sealed habitat, and their only contact with the
outside was through computers and telephones.
Before the two years were up, however, the experiment failed. Supplemental oxygen
was pumped into the facility, and food supplies were provided through the airlocks.
What caused the failure of the experiment? It was traced to nutrient pollution. The soil
in some of the biosphere ecosystems was unusually rich in nutrients. These excess
nutrients caused a huge population explosion in decomposer bacteria, which led to
oxygen depletion.
How could a population explosion of bacteria lead to oxygen depletion?
A) The excess consumers used the oxygen for cellular respiration.
B) The excess producers used the oxygen to complete photosynthesis.
C) The excess decomposers removed all the nutrients from the habitat.
D) The excess decomposers prevented plants from performing photosynthesis.
Which of the following statements regarding prokaryotes is false?
A) Prokaryotic chromosomes are more complex than those of eukaryotes.
B) Most prokaryotes reproduce by binary fission.
C) Prokaryotic cells are generally smaller and simpler than eukaryotic cells.
D) In prokaryotes, daughter chromosomes are separated by an active movement away
from each other and the growth of a new plasma membrane between them.
Hyperthyroidism treatment in cats usually involves antithyroid medication or the use of
radioactive iodine to destroy the abnormal (overactive) tissue growing in the thyroid
gland. Surgery to remove the abnormal tissue is generally not advised, as the surgery
could also accidentally destroy parathyroid tissue. The parathyroid gland releases a
hormone called PTH that increases blood calcium levels. Based on your knowledge of
homeostasis, predict why surgery is ill-advised.
A) A lack of PTH will cause blood calcium levels to drop to abnormally low levels.
B) A lack of PTH will cause blood calcium levels to rise to abnormally high levels.
C) Positive feedback will compensate for any problems caused by negative feedback.
D) Surgery will not be a problem because homeostasis will find other ways to regulate
blood calcium.
________ are a major source of restriction enzymes.
A) Plant cells
B) Human cells
C) Archaea cells
D) Bacterial cells
Which of the following statements regarding rods and cones is true?
A) Rods are more sensitive to light than cones.
B) Cones are responsible for night vision.
C) Rods are found at the greatest density at the fovea, the retina’s center of focus.
D) Rods contain the visual pigment called photopsin.
Miller was the first to show that
A) amino acids and other organic molecules could have formed under conditions
thought to resemble those of early Earth.
B) the earliest forms of life were photosynthetic.
C) eukaryotic life evolved from early prokaryotes.
D) the earliest forms of life had an RNA genome.
Thermoregulation, an important part of homeostasis, is defined as
A) a mechanism for utilizing body fat for energy.
B) reduced blood flow to an animal’s extremities in order to conserve heat.
C) the maintenance of internal body temperature within an optimal range despite
change in external temperature.
D) the mechanisms that allow an animal to hibernate without food or drink.
DDT and mercury
A) were once used as an energy source.
B) contribute to acid precipitation.
C) accumulate in the tissues of organisms.
D) deplete the ozone layer.
Which part of this figure depicting a gastrula is the mesoderm?
A) part A
B) part B
C) part C
D) part D