Name
Last
Practice Exam, Answers in Bold
First
ID#___________________________
Biology 11 – Drs. Barnosky and Quail
Spring 2005
Midterm 1 Practice
NOTE THAT THESE ARE QUESTIONS FROM LAST YEAR’S MIDTERM
SOME WE MAY NOT HAVE COVERED YET THIS YEAR
DO NOT OPEN EXAM UNTIL INSTRUCTED TO DO SO
Please Read the Instructions First
Check your pages. There are 11 pages in this exam.
You are responsible for making sure that you have all the pages.
This examination is worth 100 points.
Write your name and ID# on your scantron.
Do not use a calculator.
Multiple Choice Questions
1. Indicate your answers on the scantron sheet using a number 2 or test scoring pencil. Press
heavily, don’t stray out of the margins, and completely erase any changed answers.
2. If you think that a multiple choice question is ambiguous or confusing, use the “gripe sheet” at
the end of the examination to explain the problem.
3. There are 20 multiple choice or true/false questions worth 3 points each.
Fill–in and Short-Answer Questions
1. Use pen only (no grade corrections for pencil or white-out).
2. Write only one answer per question. You can elaborate on an answer, but you will not be
given any credit if you write two different answers to the question.
3. Spelling rules: ½ credit for 2–3 letters wrong or transposed. No points will be given if the
misspelling alters the meaning of the word.
4. There are 13 fill–in questions worth 40 points in total.
1
Choose the one best answer:
1. Which of the following is a TRUE statement?
A.
B.
C.
D.
E.
Organisms contain organic macromolecules.
Organisms evolve (their genes change from generation to generation).
Organisms reproduce by passing along DNA.
The cell is the smallest unit retaining characteristics of life.
All of the above.
2. While walking along the beach in California, you find a blob that looks like it’s probably an
animal. It is round, soft, squishy, translucent, and about the size of a softball. It has no
spicules, no spines, no segmentation, no shell, and no external or internal skeleton. It is most
likely a member of which phylum?
A.
B.
C.
D.
E.
Arthropoda
Cnidaria
Echinodermata
Mollusca
Platyhelminthes
3. What determines the ultimate appearance of an individual?
A.
B.
C.
D.
E.
environmental effects on the phenotype
genes
rate of mutation in somatic (non-gametic) cells
all of the above
A and B only
A
4. In the diagram to the right, a semipermiable membrane separates two
columns of water. If the large particles shown cannot pass across the
membrane, but water can, what will be the outcome due to osmosis?
A.
B.
C.
D.
E.
The water level in A and B will both increase.
The water level in A will decrease and the water level in B will increase.
The water level in A will increase and the water level in B will decrease.
The water level in A will increase and the water level in B will stay the same.
There will be no change in either water level.
5. The distinction between the commonly used terms invertebrates and vertebrates
A.
B.
C.
D.
E.
has no basis in morphological differences between the two groups
involves the presence and absence of a notochord
is at the taxonomic level of subphylum
is based on intelligence of the representative organisms
requires the two groups to be in separate phyla
2
B
6. Consider the following hypothetical, 3–dimensional, moist organisms living on land. Based
only on their surface-to-volume ratios, which organism would absorb oxygen from the air
fastest?
A
A.
B.
C.
D.
B
C
Species A
Species B
Species C
They would all absorb oxygen at the same rate.
7. In a two allele system where A is dominant to a, what are the chances of a curly–haired
father (Aa) and a straight–haired mother (aa) producing a curly–haired child?
A.
B.
C.
D.
E.
0%
25%
50%
75%
100%
8. As discussed in lecture, the Burgess Shale organisms
A.
B.
C.
D.
E.
Are all extinct
Fed on micronutrients in the shale to supplement their autotrophic existence
Lived in harsh environments such as mountaintops and deep sea vents
Were the first mammals on earth
Were the first organisms on earth to develop wings
9. When pink snapdragons are produced from the cross of a red snapdragon plant with a white
snapdragon plant, the result is an example of
A.
B.
C.
D.
E.
a mutation
crossing over
epistasis
incomplete dominance
pleiotropy
3
10. Which of the following is a TRUE statement regarding proteins?
A.
B.
C.
D.
E.
Proteins are broken down to start glycolysis and yield ATP.
Proteins are made of chains of lipids joined by hydrogen bonds.
Proteins make up enzymes which speed up metabolic reactions.
The lipid chains of proteins are made from 64 amino acids.
All of the above.
11. What is the total number of different phyla represented by all of the following animals?






a sea anemone
a sea cucumber
a sea lion
a sea snake
a sea star
a sea urchin
A.
B.
C.
D.
E.
2
3
4
5
6
12. True or False. Mutations can be caused by changes in the nucleotide sequence of genes in
the DNA molecule.
A. True
B. False
13. True or False. A cladogram is a diagram with branch points showing relative relationships
among taxa using shared-derived characters (synapomorphies).
A. True
B. False
14. A one-way or complete gut is found in which of the following groups?
A.
B.
C.
D.
E.
Annelida, Arthropoda, Chordata, Echinodermata, Platyhelminhtes
Annelida, Arthropoda, Chordata, Echinodermata, Mollusca, Nematoda
Chordata, Echinodermata, Platyhelminthes
Cnidaria and Porifera
Cnidaria, Nematoda, Platyhelminthes, Porifera
4
15. Adaptations for a parasitic lifestyle as exhibited by members of the Platyhelminthes and
Nematoda include
A. Development of elaborate attachment structures such as hooks, suckers, scolex, etc.
B. Increased reproductive capacity through asexual multiplication of specialized life cycle
stages.
C. Increased cephalization to detect changes in the prey’s immune system.
D. choices A and B only
E. choices A, B, and C
16. The most species-rich phylum is the
A.
B.
C.
D.
E.
Annelida
Arthropoda
Chordata
Cnidaria
Mollusca
17. A penguin (pictured at the right) is a member of what taxonomic grouping?
A.
B.
C.
D.
E.
Phylum Chordata
Phylum Coelomata
Phylum Invertebrata
Phylum Vertebrata
Subphylum Notochordata
18. Characters shared by two groups and their immediate common ancestor are
A.
B.
C.
D.
E.
convergent
homologous
homoplasious
homozygous
phenotypically superior
19. What single characteristic separates the Phylum Chordata from all other phyla?
A.
B.
C.
D.
E.
a complete gut
bilateral symmetry
coelom
dorsal tubular nerve cord
muscles
20. Annelids and Arthropods are similar in that they both have
A.
B.
C.
D.
E.
a reduced coelom
a water vascular system
an open circulatory system
external segmentation
members with wings
5
Short answer questions.
21. Place the following five levels of biological organization in the correct order with the
smallest on the bottom and the largest on top: Cell, Community, Ecosystem,
Multicelled Organism, Organelle (2 pts. – no partial credit)
Largest
A.
B.
C.
D.
E.
Smallest
Answer: (smallest to largest) Organelle, Cell, Multicelled Organism, Community,
Ecosystem
22. What is the primary structural difference between prokaryotes and eukaryotes? (1 pt.)
Give the common name of an example of a prokaryote and a eukaryote. (1 pt.)
Prokaryotes have no nucleus. Example: bacteria (Archaebacteria or Eubacteria)
Eukaryotes have a nucleus. Example: any protistan, fungus, plant, or animal
23. Chose one animal cell organelle. Give the name and a very short description (1 to 5 words)
of the function of that organelle. (2 pts.)
Name of Organelle
Function
Possible Answers:
Nucleus: storage of DNA/chromosomes
Golgi Body: packages proteins/lipids
Lysosome: sac of digestive enzymes
Mitochondria: produces energy/ATP
Endoplasmic reticulum: protein synthesis
No credit for ribosomes, cytoskeleton, flagella, or cilia since they don’t have membranes and
aren’t considered organelles. Cell membrane is not entirely within the cytoplasm of a cell
and is therefore not considered an organelle.
6
24. Give one property of water discussed in class and explain why it’s important. (2 pts.)
A. Water is slightly polar. It can hydrogen bond to itself or many other polar
molecules.
B. Water repels nonpolar molecules such as oils. A thin, oily membrane separates the
inside of a cell from the outside.
C. Water stabilizes temperatures.
1. Hydrogen bonds buffer changes in temperature. Water can absorb heat to break
hydrogen bonds before raising its temperature.
2. Large inputs of heat break hydrogen bonds and surface water molecules escape
into the air or evaporate. The water molecules carry away heat and have a cooling
effect.
3. Hydrogen bonds in ice resist breaking.
D. Water is cohesive (stands on a surface). Water can be pulled up pipelines in plant
roots and stems to the leaves.
E. Water is a great solvent. Many things dissolve in it (ions, polar molecules, etc.).
[Water is used in many metabolic reactions.]
25. Describe two differences between DNA and RNA. (2 pts.)
1.
2.
Any two of the following comparisons are acceptable:
DNA
RNA
Double helix
Single helix
Deoxyribose sugar ((C5H10O4)
Ribose sugar (C5H10O5)
Nitrogenous bases are Adenine, Nitrogenous bases are Adenine,
Cytosine, Guanine, Thymine
Cytosine, Guanine, Uracil
Contains the genetic code which Translates DNA into proteins
must be transcribed by RNA
Stays in nucleus
Leaves nucleus
26. What organic molecule makes up the cell membrane and how many layers does it have?
(1 pt.)
The cell membrane is a lipid bilayer.
7
27. Match the distinguishing cell type or key innovation with the best choice of representatives
of the phyla studied in lecture. A single letter from the right hand column may only be used
once. Be sure to write legibly! (5 pts.)
acoelomate
B
A. Crustaceans and Insects
chitinous exoskeleton
A
B. Flatworms
choanocytes (collar cells)
E
C. Sea Anemones
closed circulatory system
D
D. Segmented Worms
cnidocytes
C
E. Sponges
28. Describe two ways sexual reproduction can be a source of genetic variation. (2 pts.)
Any two of the following possible answers are acceptable:
a. independent assortment of chromosomes (during meiosis) produces gametes with
new combinations
b. chromosomal crossing–over (during meiosis) produces new combinations of linked
genes in homologous chromosomes.
c. the random fusion of gametes from both parents produces additional variation.
Answers to Questions 29 through 33 will not be posted. Please see a GSI (Crissy Huffard
or Jon Penterman) or Dr. Peter Quail to view the key for this section of the exam.
29. List the major complex organic molecules that are the basis of life, and list the simple
organic molecules (building blocks) from which each complex molecule is assembled.
(5 pts.)
Amino Acids
Proteins
Sugars
Disaccharides to Polysaccharides (sucrose and carbohydrates OK)
Glycerol and
Fatty acids
Lipids
Nucleotides
Nucleic Acids (DNA and RNA)
[1 pt. for each building block; ½ pt. per complex molecule pair; 1 bonus pt. for all correct]
8
30. Draw a simple evolutionary tree showing how the major groups of cells and organisms
evolved from the first prokaryotes. (5 pts)
[
1 pt.
Archaebacteria
1 pt.
1 pt.
Archaebacteria
Ancestor of
Eukaryotes
First
Prokaryotes
Eubacteria
1 pt.
(for
endosymbiosis)
1 pt.]
Animal
Cells
Eukaryotes
Aerobic
Eubacteria
Eubacteria
Anaerobic
Eubacteria
Cyanobacteria
Plant
Cells
31. List the three main features of the Cell Theory of Life. (3 pts.)
1. All organisms consist of one or more cells.
2. The cell is the smallest unit with the characteristics of life.
3. Each new cell arises from pre-existing cells.
[1 pt. for each feature]
32. What are the major steps in the evolution of eukaryotes from prokaryotes? (4 pts.)
1. Development of a nuclear membrane surrounding the DNA to make a nucleus.
2. Development of cytomembranes (ER, Golgi, etc.)
3. Endosymbiosis – acquisition of one (animals) or two (plants) other prokaryotic cells
as permanent intracellular residents.
[1 pt. for each step and 1 bonus pt. for all correct]
9
33. What are the major structural features of mitochondria and chloroplasts? Use labeled
diagrams to illustrate. How do these organelles replicate during cell reproduction? (5 pts.)
Mitochondria:
Chloroplasts:
Outer
Membrane
Outer
Membrane
Inner
Membrane
Inner
Membrane
Circular DNA
Circular DNA
Stomal
membranes
Circular DNA replicates. Organelle then divides by fission, like prokaryotes.
[2 pts. for Mitochondria; 2 pts. for Chloroplasts; 1 pt. for division]
10
Name: ____________________________________
Last
First
ID#________________________
Gripe Sheet
Instructions:
1. Put your name at the top of the page (we tear it off from the rest of the exam).
2. If you think that a question is ambiguous or confusing, indicate the question number, the
answer you gave, and the reason that you gave this answer.
Question # Answer you gave
Gripe
11