Chitin is a major component of the _____.
A) skeleton of mammals
B) hydrostatic skeletons of earthworms
C) exoskeleton of insects
D) body hairs of mammals
Density-dependent inhibition is a phenomenon in which crowded cells stop dividing at
some optimal density and location. This phenomenon involves binding of a cell-surface
protein to its counterpart on an adjoining cell’s surface. A growth inhibiting signal is
sent to both cells, preventing them from dividing. Certain external physical factors can
affect this inhibition mechanism.
Select the statement that makes a correct prediction about natural phenomena that could
occur during the cell cycle to prevent cell growth.
A) As cells become more numerous, they begin to squeeze against each other,
restricting their size and ability to allow cell growth.
B) As cells become more numerous, the protein kinases they produce begin to compete
with each other until only one cell has the proteins necessary for growth.
C) As cells become more numerous, the amount of required growth factors and
nutrients per cell becomes insufficient to allow for cell growth.
D) As cells become more numerous, more and more of them enter the synthesis part of
the cell cycle and duplicate DNA to inhibit cell growth.
Which of the following is a true statement about sexual vs. asexual reproduction?
A) Asexual reproduction, but not sexual reproduction, is characteristic of plants and
fungi.
B) In sexual reproduction, individuals transmit half of their nuclear genes to each of
their offspring.
C) In asexual reproduction, offspring are produced by fertilization without meiosis.
D) Asexual reproduction produces only haploid offspring.
Angiosperms are the most successful terrestrial plants. Which of the following features
is unique to them and helps account for their success?
A) wind pollination
B) dominant gametophytes
C) fruits enclosing seeds
D) sperm cells without flagella
The color of throats of males in a population of side-blotched lizards is determined by
_____.
A) ambient temperature: blue = cold; orange = normal; yellow = hot
B) stage of development/maturity
C) their receptiveness to mate
D) the success of the mating behavior of each of the throat color phenotypes
In humans, the follicular cells that remain behind in the ovary following ovulation
become _____.
A) the ovarian endometrium that is shed at the time of the menses
B) a steroid-hormone synthesizing structure called the corpus luteum
C) the thickened portion of the uterine wall
D) the placenta, which secretes cervical mucus
Water flows into the source end of a sieve tube because _____.
A) sucrose has been actively transported into the sieve tube, making it hypertonic
B) water pressure outside the sieve tube forces in water
C) the companion cell of a sieve tube actively pumps in water
D) sucrose has been transported out of the sieve tube by active transport
How were conditions on the early Earth of more than three billion years ago different
from those on today’s Earth? Unlike Earth today, early Earth _____.
A) had an atmosphere rich in gases released from volcanic eruptions
B) had an oxidizing atmosphere
C) experienced little high energy radiation from the sun
D) had an atmosphere with significant quantities of ozone
There are more species in tropical areas than in places more distant from the equator.
This is probably a result of _____.
A) fewer predators
B) more intense annual solar radiation
C) more frequent ecological disturbances
D) fewer agents of disease
Which of the following statements concerning animal taxonomy is (are) true?
1. Animals are more closely related to plants than to fungi.
2. All animal clades based on body plan have been found to be incorrect.
3. Kingdom Animalia is monophyletic.
4. Animals only reproduce sexually.
5. Animals are thought to have evolved from flagellated protists similar to modern
choanoflagellates.
A) 1 and 2
B) 3 and 5
C) 3, 4, and 5
D) 2 and 4
Use this description to answer the following questions.
A major group of G protein-coupled receptors contains seven transmembrane α helices.
The amino end of the protein lies at the exterior of the plasma membrane. Loops of
amino acids connect the helices either at the exterior face or on the cytosol face of the
membrane. The loop on the cytosol side between helices 5 and 6 is usually substantially
longer than the others.
The coupled G protein most likely interacts with this receptor _____.
A) at the NH3 end
B) at the COO” end
C) along the exterior margin
D) at the loop between H5 and H6
Which of the following is an example of potential rather than kinetic energy?
A) water rushing over Niagara Falls
B) light flashes emitted by a firefly
C) a molecule of glucose
D) a crawling beetle foraging for food
Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long
tails (t). What fraction of the progeny of crosses BbTt BBtt will be expected to have
black fur and long tails?
A) 1/16
B) 3/8
C) 1/2
D) 9/16
Steroid hormones produce their effects in cells by _____.
A) activating key enzymes in metabolic pathways
B) activating translation of certain mRNAs
C) promoting the degradation of specific mRNAs
D) binding to intracellular receptors and promoting transcription of specific genes
The M-phase checkpoint ensures that all chromosomes are attached to the mitotic
spindle. If this does not happen, cells would most likely be arrested in _____.
A) telophase
B) prophase
C) prometaphase
D) metaphase
Compared to oxidative skeletal muscle fibers, those classified as glycolytic typically
have _____.
A) a higher concentration of myoglobin
B) a higher density of mitochondria
C) a smaller diameter
D) less resistance to fatigue
At the moment of sperm penetration, human eggs _____.
A) have used flagellar propulsion to move from the ovary to the oviduct
B) are still located within the ovary
C) have a paper-thin cell of calcium carbonate that prevents desiccation
D) are still surrounded by follicular cells
The phylogenetic tree below _____.
A) depicts the three major domains of life
B) includes unicellular but not multicellular life
C) includes unicellular and some forms of multicellular life, but not complex animals
and plants
D) includes noncellular life-forms
A natural predator of the crown-of-thorns sea star is a mollusc called the Giant Triton,
Charonia tritonis. If the triton uses a radula to saw into the sea star, then to which clade
should the triton belong?
A) chitons
B) bivalves
C) gastropods
D) cephalopods
Which of the following supports the finding that sugar translocation in phloem is an
active (energy-requiring) process?
A) Sucrose occurs in higher concentrations in companion cells than in the mesophyll
cells where it is produced.
B) Movement of water occurs from xylem to phloem and back again.
C) Strong pH differences exist between the cytoplasm of the companion cell and the
mesophyll cell.
D) ATPases are abundant in the plasma membranes of the mesophyll cells.
Eukaryotes that are not closely related and that do not share many anatomical
similarities can still be placed together on the same phylogenetic tree by comparing
their _____.
A) plasmids
B) mitochondrial genomes
C) homologous genes that are poorly conserved
D) homologous genes that are highly conserved
In a biological reaction, succinate dehydrogenase catalyzes the conversion of succinate
to fumarate. The reaction is inhibited by malonic acid, a substance that resembles
succinate but cannot be acted upon by succinate dehydrogenase. Increasing the amount
of succinate molecules to those of malonic acid reduces the inhibitory effect if malonic
acid. Select the correct identification of the molecules described in the reaction.
A) Succinate dehydrogenase is the enzyme, and fumarate is the substrate in the
reaction.
B) Succinate dehydrogenase is the enzyme, and malonic acid is the substrate in the
reaction.
C) Succinate is the substrate, and fumarate is the product in the reaction.
D) Fumarate is the product, and malonic acid is a noncompetitive inhibitor in the
reaction.
Which of the following characteristics is (are) possessed in common by true mosses,
ferns, and spike mosses, and therefore becomes useless at helping to determine to which
of these groups “flower of stone” belongs?
1. a sporophyte generation that is dominant
2. true leaves and roots
3. flagellated sperm
4. strobili
5. alternation of generations
A) 5 only
B) 1 and 5
C) 2 and 3
D) 3 and 5
A cluster of tumor cells that produces and secretes growth factors to induce surrounding
cells to grow and divide is showing which type of cell-to-cell signaling?
A) autocrine
B) paracrine
C) endocrine
D) neuroendocrine
Which functional group shown above is characteristic of alcohols?
A) A
B) B
C) C
D) D
Most of the ATP supplies for a skeletal muscle undergoing one hour of sustained
exercise come from _____.
A) creatine phosphate
B) glycolysis
C) substrate phosphorylation
D) oxidative phosphorylation
Knowing the atomic mass of an element allows inferences about which of the
following?
A) the number of electrons in the element
B) the number of protons in the element
C) the number of protons plus neutrons in the element
D) the number of protons plus electrons in the element
Substrate-level phosphorylation occurs _____.
A) in glycolysis
B) in the citric acid cycle
C) in both glycolysis and the citric acid cycle
D) during oxidative phosphorylation
Why is glycolysis considered to be one of the first metabolic pathways to have
evolved?
A) It produces much less ATP than does oxidative phosphorylation.
B) It does not involve organelles or specialized structures, does not require oxygen, and
is present in most organisms.
C) It is found in prokaryotic cells but not in eukaryotic cells.
D) It requires the presence of membrane-enclosed cell organelles found only in
eukaryotic cells.
A student encounters a pondweed which appears to be a charophyte (stonewort). Which
of the following features would help the student determine whether the sample comes
from a charophyte or from some other type of green alga?
1. molecular structure of enzymes inside the chloroplasts
2. structure of sperm cells
3. presence of phragmoplasts
4. rings of cellulose-synthesizing complexes
A) 1 and 3
B) 1 and 4
C) 2 and 3
D) 2, 3, and 4