Download The questions below were presented in different

BIOL 241 (0439.25)
Exam #1
October 15, 2014
The questions below were presented in different sequences on different
versions of the exam.
You are studying cells that are being grown in a research lab. You add a drug that stops the
nuclear envelope (nuclear membrane) from disintegrating, thus stopping further progression
through the cell’s life cycle. If you add this drug to actively growing cells, in what stage of the
life cycle will the cells be “frozen”? Briefly explain. Will each of these cells have enough
organelles for one cell, or for two? Briefly explain. [about 2 sentences]
Since the nuclear membrane normally disintegrates during prophase of mitosis, cells would
likely be “frozen” at this stage. Each cell would have enough organelles for two cells after
duplicating its organelles in stage G1 of interphase.
Briefly describe 3 differences (structural and/or functional) between cardiac muscle cells and
smooth muscle cells. [about 3 sentences]
Some possible differences include:
 Cardiac muscle cells are striated, reflecting organization of thin and thick filaments
(actin and myosin), whereas smooth muscle cells are not.
 Cardiac muscle cells can be branched whereas smooth muscle cells are not.
 Cardiac muscle cells have more mitochondria than smooth muscle cells.
 Cardiac muscle cells have prominent intercalated discs and gap junctions; these features
are de-emphasized or missing in smooth muscle cells.
 Cardiac muscle cells are found only in the heart and are responsible for contraction of
the heart, while smooth muscle cells help move fluids though a variety of tubes (blood
vessels, digestive tract, etc.).
Briefly describe an example of how a negative feedback system maintains homeostasis. Be sure
to indicate both what is regulated and how it is regulated. [about 3 sentences]
A perfect answer would include 3 components:
 an example of a regulated parameter (body temperature, levels of a hormone like
testosterone, etc.)
 some information about sensors and/or effectors relevant to the example chosen
 the idea that changes away from a setpoint value are counteracted
On Side A of an artificial membrane permeable only to water, the solutes are sodium (100 mM)
and chloride (100 mM). On Side B of the membrane, the solutes are sodium (60 mM), chloride
(60 mM), and glucose (60 mM). Will water move from A to B, from B to A, or neither?
Explain. [about 2 sentences]
Water will flow to the side with the highest solute concentration. Since Side A has a higher solute
concentration than Side B (200 mM vs. 180 mM), water will move from B to A.
1
BIOL 241 (0439.25)
Exam #1
October 15, 2014
Explain why your elbow swells up after you scrape it. [about 3 sentences]
The scraping injures the epithelial tissue and underlying connective tissue. Mast cells in the
connective tissue release histamine and other chemical signals that lead to an increase in blood
flow to the affected area. Because of increased blood flow, some fluid in the blood vessels leaks
into the surrounding tissue, which swells.
The diaphragm is a muscle that separates the _________ from the ___________.
a. Left lung, right lung
b. Thoracic cavity, abdominopelvic cavity – YES
c. Thoracic cavity, vertebral cavity
d. Vertebral cavity, cranial cavity
Which sectional plane could divide the body so that the face remains intact?
a. Equatorial plane
b. Frontal (coronal) plane – YES
c. Parasagittal plane
d. Sagittal plane
Consider the following set of anatomical landmarks: acromial, otic, buccal, mental. In what order
are these listed?
a. From anterior to posterior
b. From inferior to superior
c. From lateral to medial – YES
d. From superficial to deep
In a negative feedback system, which term represents the mechanism that moves the regulated
variable (temperature, joint position, etc.) back toward the setpoint?
a. Effector – YES
b. Hormone
c. Sensor
d. Vasodilator
10. Recall the division of the abdominopelvic area into 9 regions. From superior to inferior, the
left and right regions are
a. Hypochondriac, inguinal, lumbar
b. Hypochondriac, lumbar, inguinal – YES
c. Lumbar, hypochondriac, inguinal
d. Lumbar, inguinal, hypochondriac
2
BIOL 241 (0439.25)
Exam #1
October 15, 2014
Which of the following can pass through plasma membranes without the aid of any membrane
proteins?
a. Carbon dioxide (CO2) – YES
b. Chloride (Cl-)
c. Glucose (C6H12O6)
d. Potassium (K+)
A major difference between DNA and RNA is that
a. DNA is made of nucleotide bases and RNA is made of amino acids
b. DNA is double-stranded and RNA is single-stranded – YES
c. DNA includes U (uracil) instead of T (thymine)
d. RNA stays in the nucleus of a non-dividing cell while DNA moves from the nucleus to
ribosomes
The genetic code is called a triplet code because
a. amino acids are brought to the ribosome in groups of 3
b. each set of 3 nucleotide bases corresponds to 1 amino acid – YES
c. genes are transcribed in groups of 3
d. it takes 3 genes to make 1 protein
The most common mutation responsible for cystic fibrosis changes a membrane channel that is
important in the function of
a. connective tissue
b. epithelial tissue – YES
c. nervous tissue
d. all of the above
Which organelles are primarily responsible for harvesting the energy of food to make ATP?
a. Lysosomes
b. Mitochondria – YES
c. Nuclei
d. Ribosomes
16. You want to predict the rate at which Substance X will diffuse through a plasma membrane
in an experiment. What information will you want to know about Substance X?
a. X’s molecular weight
b. X’s concentration on each side of the membrane
c. the temperature at which the experiment will be done
d. ALL of the above information is useful – YES
3
BIOL 241 (0439.25)
Exam #1
October 15, 2014
The export of proteins out of the cell, using vesicles, is an example of
a. Diffusion
b. Endocytosis
c. Exocytosis – YES
d. Phagocytosis
How does growth hormone affect the cell life cycle?
a. It acts as food that cells can break down for extra energy, allowing them to grow faster.
b. It and its receptor attract chromosomes to the metaphase plate, speeding up mitosis.
c. It binds to receptors on the cell surface that relay signals inside of the cell, eventually leading
to changes in gene expression that speed up the cell cycle. – YES
d. It causes cells to absorb organelles from the blood, thus speeding up phase G1.
The main function of areolar tissue is to
a. Carry oxygen and carbon dioxide through the blood
b. Contract in order to move bones
c. Cushion and protect body organs – YES
d. Transmit information through the nervous system
Which of the following anchor epithelial cells to the basement membrane?
a. Gap junctions
b. Hemidesmosomes – YES
c. Tight junctions
d. all of the above
The striations of some muscle cells are due to these cells’ arrangements of
a. Actin and myosin (thin and thick filaments) – YES
b. Centrioles and chromosomes
c. Golgi bodies and vesicles
d. Ribosomes and ER
Connective tissue includes 3 basic components: cells, extracellular protein fibers, and an
extracellular fluid known as
a. collagen
b. cytoplasm
c. fibroblasts
d. ground substance – YES
Which is NOT true of cells lining the trachea?
a. Some are goblet cells.
b. They are cuboidal. – YES
c. They have a pseudostratified appearance.
d. They have cilia.
4
BIOL 241 (0439.25)
Exam #1
October 15, 2014
What do adipocytes have in common with epithelial cells?
a. Both are flattened in appearance.
b. Both have a very short lifespan and are replaced frequently.
c. Both have very limited extracellular space between them. – YES
d. Both store large amounts of fat.
One difference between dense regular and dense irregular connective tissue is that dense regular
tissue
a. has most of its extracellular fibers oriented in the same direction (in parallel) – YES
b. has relatively few cells but lots of extracellular protein fibers
c. includes lots of collagen
d. is found between vertebrae of the spinal column
Which of the following is NOT a type of cell that is regularly found in connective tissue proper?
a. Chondrocytes – YES
b. Fibroblasts
c. Mast cells
d. Mesenchymal cells
As you get older, your risk of developing cancer generally increases because multiple
______________ accumulate over time.
a. DNA mutations – YES
b. mitotic spindles
c. nuclei
d. organelles
A difference between a typical neuron and a typical sperm cell is that
a. sperm cells are larger than neurons
b. sperm cells have only one long, thin extension of the cell body, whereas neurons have many –
YES
c. sperm cells have numerous mitochondria to fuel their swimming
d. sperm cells are found in the spinal cord
In which kind of connective tissue can you normally see a mix of cells that do and do not have
nuclei?
a. Connective tissue proper
b. Fluid connective tissue – YES
c. Hyaline cartilage
d. Supporting connective tissue
Which kind of connective tissue is a major component of the walls of large arteries?
a. dense irregular
b. dense regular
c. elastic – YES
d. smooth muscle
5