AP Biology Sample First Semester Exam 2019 Section I PART A
Multiple Choice Questions
1) The partial negative charge in a molecule of water occurs because 1) _______
A) the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus.
B) the oxygen atom forms hybrid orbitals that distribute electrons unequally around the oxygen nucleus.
C) one of the hydrogen atoms donates an electron to the oxygen atom.
D) the oxygen atom has two pairs of electrons in its valence shell that are not neutralized by hydrogen atoms.
E) the oxygen atom acquires an additional electron.
2) One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3).
Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+). Thus,
H2CO3 ↔ HCO3- + H+
If the pH of the blood drops, one would expect
2) _______
A) a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-.
B) the concentration of hydroxide ion (OH-) to increase.
C) the HCO3- to act as an acid and remove excess H+ with the formation of H2CO3.
D) the concentration of bicarbonate ion (HCO3-) to increase.
E) the HCO3- to act as a base and remove excess H+ with the formation of H2CO3.
3) Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
3) _______
A) Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers.
B) Dehydration reactions can occur only after hydrolysis.
C) Hydrolysis creates monomers, and dehydration reactions break down polymers.
D) Dehydration reactions eliminate water from lipid membranes, and hydrolysis makes lipid membranes water permeable.
E) Dehydration reactions ionize water molecules and add hydroxyl groups to polymers;
hydrolysis reactions release hydroxyl groups from polymers.
4) The figure below illustrate the process of
4) _______
A) cotransport B) Passive diffusion
C) Receptor mediated endocytosis
D) phagocytosis E) pinocytosis
Figure 5.5
5) Which of the following statements is/are true regarding the chemical reaction illustrated in Figure 5.5?
5) _______
A) It is a hydrolysis reaction.
B) It joins two fatty acids together.
C) It is a hydrolysis reaction and it results in a peptide bond.
D) It results in a peptide bond.
E) It is a hydrolysis reaction, it results in a peptide bond, and it joins two fatty acids together.
6) Which type of organelle or structure is primarily involved in the synthesis of oils, phospholipids, and steroids?
6) _______
A) ribosome B) mitochondrion C) contractile vacuole D) lysosome
E) smooth endoplasmic reticulum
7) The Golgi apparatus has a polarity or sidedness to its structure and function. Which of the following statements correctly describes this polarity?
7) _______
A) They contain hydrolytic enzymes on receiving side to digest molecules.
B) Soluble proteins in the cisternae (interior) of the Golgi move from one side of the Golgi to the other without any modification.
C) Transport vesicles can fuse anywhere in cisternae.
D) Only lipid molecules in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.
E) The cis face receives vesicles from ER, whereas the trans face ships vesicle.
8) Which of the following organelles are NOT found in animal cells. 8) _______
A) Lysosomes B) Centrioles
C) Extracellular matrix D) Desmosomes
E) plasmodesmata
9) Which of the following statements describes the results of this reaction?
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy
9) _______
A) O2 is reduced and CO2 is oxidized.
B) C6H12O6 is oxidized and O2 is reduced.
C) O2 is oxidized and H2O is reduced.
D) C6H12O6 is reduced and CO2 is oxidized.
E) CO2 is reduced and O2 is oxidized.
10) During aerobic respiration, electrons travel downhill in which sequence? 10) ______
A) food → NADH → electron transport chain → oxygen B) food → glycolysis → citric acid cycle → NADH → ATP C) food → citric acid cycle → ATP → NAD+
D) glucose → ATP → electron transport chain → NADH E) glucose → pyruvate → ATP → oxygen
11) Which of the following best describes how chromosomes split and move toward the poles of the spindle during mitosis?
11) ______
A) Nonkinetochore spindle fibers serve to push chromatids in the direction of the poles.
B) Sister chromatids are pulled apart by motor molecules interacting with kinetochore microtubules.
C) The chromosomes are "reeled in" by the contraction of spindle microtubules, motor proteins of the nonkinetochores move the chromosomes in the direction of the poles.
D) The chemical bonds between chromatids are broken apart.
E) Motor proteins move the chromosomes along the spindle microtubules.
12) When cyclin connect with cyclin-dependent kinases (Cdks), which of the following events would occur?
12) ______
A) Enough MPF would be produced to pass G2 checkpoint and initiate the events of mitosis.
B) They give the stop signal and cell stops dividing.
C) They inactivate other proteins and cell growth stop.
D) Cell enters a non dividing phase called the G0 phase.
E) They stop responding to cyclins.
Figure 12.2
13) If an animal cell whose nuclear material is shown in Figure 12.2 continues toward completion of mitosis, which of the following events would occur in cytokinesis?
13) ______
A) cleavage furrow forms B) synthesis of chromatids C) nuclear envelope breakdown D) cell plate forms
E) binary fission
14) Which of these statements is false? 15) ______
A) Single, haploid (n) sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote.
B) At sexual maturity, ovaries and testes produce diploid gametes by meiosis.
C) Sexual life cycles differ with respect to the relative timing of meiosis and fertilization.
D) In humans, the 23rd pair, the sex chromosomes, determines whether the person is female (XX) or male (XY).
E) In humans, each of the 22 maternal autosomes has a homologous paternal chromosome.
15) Which of the following statements best represents the relationships between the light reactions and the Calvin cycle?
a. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, i, and NADP+ to the light reactions.
b. The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions.
c. The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP.
d. The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split.
16) All of the following statements about photosynthesis are true EXCEPT 17) ______
A) The light reactions convert solar energy to chemical energy in the form of ATP and NADPH
B) The Calvin cycle uses ATP and NADPH to convert CO2 to sugar
C) Photosystem I contains P700 chlorophyll a molecules at the reaction center; photosystem II contains P680 molecules
D) In chemiosmosis, electron transport chains pump protons (H+) across a membrane from a region of high H+ to a region of low H+ concentration.
E) One of the source of proton motive force generation is the removal of hydrogen ion from the stroma when NADP+ is reduced to NADPH
17) Which of the following is NOT the mechanism of an enzyme to speed up a reaction:
a. puts stress on substrate bonds that must be broken
c. active site orients substrate in correct position
b. provides energy to substrate making it unstable
d. provides a favorable microenvironment for a reaction to occur.
18)
18) Noncompetitive inhibitors do not directly combine with substrate molecule; instead, they impede enzyme activity by impede enzyme activity by binding to
19) ______
A) coenzyme B) cofactor C) substrate D) active site
E) allosteric site
19) Which of the following is NOT true of homologous chromosomes? ______
A) They behave independently in mitosis B) They synapse during S phase of meiosis
C) They travel together to metaphase plate in prometaphase of meiosis I D) Each parent contributes one set of homologous chromosomes to an offspring
E) Crossing over between nonsister chromatids of homologous chromosomes is indicated by the presence of chiasmata.
20)
Above diagram represents which of the following molecule
A) starch.
B) glycogen.
C) chitin.
D) cellulose.
21) The activation of tyrosine kinase is characterized by A) Channel protein shape change.
B) IP3 binding
C) A phosphorylation cascade D) Dimerization and phosphorylation E) GTP hydrolysis
22) Many signal transduction pathways use second messenger to
A) Transport a signal through lipid bilayer portion of the plasma membrane.
B) Relay a signal from the outside to the inside of the cell.
C) Relay the message from the inside of the membrane through the cytoplasm.
D) Amplify the message by phosphorylating proteins.
E) Dampen the message once the signal molecule has left the receptor.
23) Which of the following is a major cause of the size limits for certain types of cells?
A) limitation on the strength and integrity of the plasma membrane as cell size increases.
B) the difference in plasma membranes between prokaryotes and eukaryotes.
C) evolutionary progression in cell size; more primitive cells have smaller sizes.
D) the need for sufficient surface area to support the cell's metabolic needs.
Section I PART B
The section consists of questions requiring numeric answers. Calculate the correct answer for each question. PART B consists of questions requiring numeric answers. Calculate the correct answer for each question.
1) A researcher estimates that, in a certain organism, the complete metabolism of glucose produces 30 molecules of ATP for each molecule of glucose. The energy released from the total oxidation of glucose under standard conditions is 686 kcal/mol. The energy released from the hydrolysis of ATP to ADP and inorganic phosphate under standard conditions is 7.3 kcal/mol.
Calculate the amount of energy available from the hydrolysis of 30 moles of ATP. Calculate the efficiency of total ATP production from 1 mole of glucose in the organism.
2) The value for Ψ in root tissue was found to be -3.3 bars. If you place the root tissue in a 0.1 M solution of sucrose at 20°C in an open beaker, what is the Ψ of the solution, and in which direction would the net flow of water be?
S e c t i o n
I I D i r e c t i o n s :
Q u e s t i Q u e s t i o n
1
i s
a
l o n g
f r e
e-response questions that should require about 22 minutes to answer and is worth 10 points.
Questions 2 through 4 are short free-response questions that should require about 6 minutes each to answer. Read each question carefully and completely. Write your response in the space provided following each question. Only material written in the space provided will be scored. Answers must be written out in paragraph form. Outline form is not acceptable. Labeled diagrams may be used to supplement discussion, but unless specifically called for by the question, a diagram alone will not receive credit.
Section II
Q1.
2. The physical structure of a protein often reflects and affects its function.
(a) Describe THREE types of chemical bonds/interactions found in proteins. For each type, describe its role in determining protein structure.
(b) Discuss how the structure of a protein affects the function of the following.
• Regulation of enzyme activity
Cell signaling
(c) Abnormal hemoglobin is the identifying characteristic of sickle cell anemia. Explain the genetic basis of the abnormal hemoglobin. Explain why the sickle cell allele is selected for in certain areas of the world.
3) The following data were collected by observing subcellular structures of three different types of eukaryotic cells.
RELATIVE AMOUNTS OF ORGANELLES IN THREE CELL TYPES
Cell Type Smooth ER Rough ER Mitochondria Cilia Golgi Bodies
X Small
amount
Small amount
Large number
Present Small amount
Y Large
amount
Large amount
Moderate number
Absent Large amount
Z Absent Absent Absent Absent Absent
Based on an analysis of the data, identify a likely primary function of each cell type and explain how the data support the identification.
4.
Answer key multiple choice question 1A
2E 3A 4A 5D 6E 7E 8E 9D 10A 11C 12A 13A 14B 15A 16C 17B 18E 19B 20D 21D 22B 23D
