Download Choose the response which best completes each of the following

Choose the response which best completes each of the following statements
or answers each of the following questions.
1. Plastids bear a striking similarity to mitochondria in that plastids
(1.) store carbohydrates, fats, and proteins (2.) synthesize green, red,
and yellow pigments (3.) are found in photosynthetic organisms only (4.)
contain DNA, RNA, and ribosomes
2. Which carbohydrate is usually NOT present in animal cells and tissues?
(1.) glucose (2.) glycogen (3.) fructose (4.) cellulose (5.)lactose
3. The evolution of the eukaryotes required the development of (1.) free
ribosomes (2.) functioning mitochondria (3.) membrane bound organelles (4.)
an activated Golgi body
4. The bond between two amino acids in a protein is called
(1.) a glycosidic bond (2.) an ester bond (3.) an ionic bond
bond
(4.) a peptide
5. A protein may be denatured by (1.) hydrolysis (2.) heat or heavy metals
(3.) action of enzymes (4.) assimilation (5.) dehydration synthesis
6. There is good evidence of linkage when (1.) genes of two different loci
segregate independently (2.) genes of two different alleles do not
segregate independently (3.) a gene is invariably associated with a
specific characteristic (4.) two genes invariably work to control the
expression of a single characteristic (5.) two genes are located together
in a single gamete
7. The organelles most closely associated with the intracellular digestion
of damaged cellular components are (1.) peroxisomes (2.) mesosomes (3.)
glyoxysomes (4.) dictysomes (5.) lysosomes
Each of the numbered items refer to the numbered statements that follow.
Select the one numbered choice which best fits each statement. A choice may
be used once, more than once, or not at all.
Questions 8-9
(1.)
(2.)
(3.)
(4.)
(5.)
Pleiotropy
Multiple Alleles
Sex linkage
Linked genes
Independent Assortment
8. This is the mode of inheritance of the ABO blood group.
9. This is the mode of inheritance of hemophilia.
10. A structure found commonly in animal cells but rarely in plant cells is
the(1.) Golgi apparatus (2.) centriole (3.) nucleus (4.) endoplasmic
reticulum (5.) mitochondrion
11. A student examining a cell under the microscope noticed the formation
of a cell plate in the midline of the cell and the formation of nuclei at
the poles of the cell. The cell under examination was most likely (1.) an
animal cell in the M phase of the cell cycle (2.) a dividing bacterial cell
(3.) a plant cell undergoing cytokinesis (4.) an animal cell undergoing
cytokinesis (5.) a plant cell in the anaphase stage
12. Which discovery provides the best evidence to support the belief that
DNA carries genetic information? (1.) Heritable transformation of bacterial
cells is brought about by DNA. (2.) The DNA content from cells of different
tissues of an organism is the same. (3.) The adenine to thymine and guanine
to cytosine ratios in DNA are equal to 1. (4.) DNA is present in
chromosomes. (5.) DNA is present in all cells that divide.
13. In guinea pigs, black is dominant. One-half of a particular litter is
white. If it is assumed the laws of chance operate, the parent cross was
most likely (1.) BB X Bb (2.) Bb X Bb (3.) Bb X bb (4.) bb X bb (5.) BB X
bb
14. To determine whether an unknown black guinea pig is pure or hybrid, it
should be crossed with (1.) a white (2.) a hybrid black (3.) a hybrid white
(4.) a pure black (5.) another unknown
15. Which set of parents could NOT be the parents of a child with type O
blood? (1.) Father type A, mother type O (2.) Father type A, mother type B
(3.) Father type B, mother type O (4.) Father type AB, mother type O (5.)
Father type O, mother type O
16. Which is true of a gene that is dominant? (1.) It is usually
detrimental. (2.) It will occur more frequently than its recessive allele.
(3.) It will occur less frequently than its recessive allele. (4.) It will
have the same phenotypic effect whether it appears in the homozygous or
heterozygous condition.
17. Phenylketonuria is a disease caused by a single gene defect. Unlike
sickle-cell anemia, it can be treated by (1.) controlling the diet of PKU
infants (2.) using vaccines to counteract the effect of the mutant gene
(3.) correcting the mutant gene by genetic engineering (4.) applying
low-level radiation doses to affected cells (5.) using the "wet diaper"
test at stated intervals
18. Chromosomes do NOT occur in pairs in (1.) body cells (2.) somatic cells
(3.) fertilized eggs (4.) gametes (5.) zygotes
19. Osmosis is a process that (1.) involves the movement of particles from
saturated solutions (2.) moves water molecules from an area of higher
concentration to an area of lower concentration, using energy (3.)
equalizes the concentration of particles by the movement of water molecules
(4.) continues until the medium on each side of the membrane has become
hypertonic (5.) regulates the tonicity on either side of the membrane
20. The endoplasmic reticulum functions as (1.) a network that binds cells
together (2.) an ultrastructural framework in the cytoplasm (3.) a
secretory and storage syncytium (4.) a network of fibers to which the
nucleoli are attached (5.) a control center for protein synthesis
21. In plants, the plastids which contain pigments that give fruit,
flowers, and autumn leaves their orange and yellow colors are known as (1.)
epiblasts (2.) leucoplasts (3.) amyloplasts (4.) chloroplasts (5.)
chromoplasts
22. A primary reason for Mendel's success in his studies of pea plant
inheritance was that (1.) he was the first person to attempt studies of
inheritance (2.) there was plenty of room in his garden (3.) he studied one
trait at a time (4.) he concentrated on the whole organism (5.) he was the
first to postulate the gene theory
23. A change affecting the base sequence in an organism's DNA is known as
(1.) replication (2.) chromosomal mutation (3.) transcription (4.)
independent assortment (5.) gene mutation
The following directions apply to questions 24-26 which follow in the question
blocks.
--------------------------------------------------------------------------Each set of numbered choices refers to the numbered words or statements
that follow it. Choose the numbered choice that best fits each word or
statement. A choice may be used once, more than once, or not at all.
Choices
(1.)
(2.)
(3.)
(4.)
(5.)
DNA molecules only
RNA molecules only
Both DNA and RNA molecules
Neither DNA or RNA molecules
ATP molecules only
24. Molecules composed of chains of nucleotides.
25. Molecules found in the nucleus of the cell.
26. Molecules that carry genetic information from the nucleus to the
ribosomes.
---------------------------------------------------------------------Choices
(1.)
(2.)
(3.)
(4.)
(5.)
(6.)
Mutation
Sex Linked recessive
Hybrid vigor
Inbreeding
Codominance
gene linkage
27. Radiation can cause definite structural changes in the DNA molecules of
chromosomes.
28. Hemophilia and colorblindness are carried on the X chromosome.
29. The alleles for two different traits are inherited together on the same
chromosome.
30. Biologists have discovered that a certain type of poison interferes
with protein synthesis. Which cell structure listed is most likely affected
by the poison? (1.) cytoplasm (2.) ribosome (3.) centrosome (4.) vacuole
(5.) mitochondrion
31. According to the fluid mosaic model of the plasma membrane, proteins
are (1.) spread out in a continuous layer over both membrane surfaces (2.)
located in the hydrophilic layer of the membrane (3.) converted to glycogen
by the hormone insulin in the peroxisomes (4.) capable of leaving the
membrane
and dissolving in the solution of the external environment (5.) embedded in the
lipid bilayers
32. A couple whose family indicates chromosomal genetic disorders seeks
genetic counseling. Which procedure would provide them with the genetic
information that would help them to plan a family? (1.) karyotyping (2.)
electrophoresis (3.) cloning (4.) genetic engineering (5.) amniocentesis
33. Which is NOT associated with cell division in animals? (1.) Duplication
of chromosomes (2.) Constriction of dividing cells (3.) Separation of
chromosomes (4.) Spindle fibers (5.) Cell plate formation
34. An enzyme that has two binding sites and exists in two or more
conformations is known as (1.) a hydrolytic enzyme (2.) an allosteric
enzyme (3.) a catalytic enzyme (4.) a catabolic enzyme (5.) an anabolic
enzyme
35. The process of transcription occurs in the (1.) mitochondrion (2.)
ribosome (3.) cytoplasm (4.) polysome (5.) nucleus
36. Which disorder is the result of meiotic nondisjunction? (1.) PKU (2.)
hemophilia (3.) Tay-Sachs disorder (4.) Down syndrome (5.) Sickle-cell
anemia
37. Which occurs during meiosis but not during mitosis? (1.) Chromosomes
align at the metaphase plate (2.) Chromosomes condense (3.) Chromosomes
migrate to opposite poles
(4.) A spindle apparatus forms (5.) Synapsis
Base your answers to questions 38 and 39 which follow on the basis of the
following paragraph and your knowledge of biology.
Sickle-cell anemia occurs in two forms, major and minor. The major form is
usually fatal in childhood while the minor form is much less severe. Normal
persons are pure for the normal gene. Persons with the major form are pure
for the abnormal gene. Persons with the minor form are hybrid.
38. If both parents have the minor form, what percent of their children are
expected to be normal? (1.) 0% (2.) 25% (3.) 50% (4.) 75% (5.) 100%
39. Which type of inheritance is illustrated by this paragraph? (1.)
complete dominance (2.) incomplete dominance (3.) codominance (4.) sex
linkage (5.) multiple genes
40. In garden pea plants, tallness is dominant over shortness, and yellow
seeds are dominant over green seeds. If a pea plant which is hybrid for
tallness and hybrid yellow seeds is crossed with a pea plant which is
heterozygous for tallness and heterozygous for yellow seeds, what
proportion of the offspring would be likely to be short with green seeds?
(1.) 1/16 (2.) 1/8 (3.) 1/4 (4.) 1/2 (5.) 9/16
41. As a result of crossing two hybrid yellow garden peas, 120 offspring
are produced. According to the laws of chance, the most probable number of
yellow offspring is (1.) 0 (2.) 30 (3.) 60 (4.) 90 (5.) 120
42. One hundred experimental matings of brown birds with white birds
produced speckled offspring. The mating of two speckled birds would
probably result in (1.) 75% white, 25% brown (2.) 25% brown, 75% white (3.)
100% speckled (4.) 25% brown, 50% speckled, 25% white (5.) 50% brown, 25%
white, 25% speckled
43. When light strikes chlorophyll molecules, they lose electrons, which
are ultimately replaced by (1.) splitting water (2.) breaking down ATP
(3.) removing them from NADPH (4.) fixing carbon (5.) oxidizing glucose
44. The overall function of the Calvin cycle is (1.) capturing sunlight
(2.) making sugar (3.) producing carbon dioxide (4.) splitting water
(5.) oxidizing glucose
45. What is rubisco? (1.) the enzyme in C3 plants that first captures
CO2 to begin the Calvin cycle (2.) the enzyme responsible for
splitting H2O to produce O2 in photosynthesis (3.) the enzyme that forms
a 4-carbon compound in CAM metabolism (4.) the first stable intermediate
in CAM metabolism (5.) the 5-carbon sugar molecule that reacts with CO2
to begin the Calvin cycle
46. Which of these wavelengths is least useful for photosynthesis?
(1.) green (2.) yellow (3.) blue (4.) orange (5.) red
47.
(1.)
(3.)
(4.)
(5.)
What is formed when pyruvate is converted to acetyl CoA?
CO2 and ATP are formed (2.) CO2 and NADH are formed
CO2 and coenzyme A are formed
one turn of the Krebs cycle is completed
(oxidized) NAD is regenerated
48. During respiration in a eukaryotic cell, reactions of glycolysis occur,
or are located, in or on (1.) the cytosol
(2.) the matrix of the mitochondrion (3.) the cristae of the mitochondrion
(4.) the intermembrane space of the mitochondrion
(5.) across the inner membrane of the mitochondrion
49. Sports physiologists at the E-KCS training center wanted to
monitor athletes to determine at what point their muscles were
functioning anaerobically. They could do this by checking for a
buildup of (1.) ATP (2.) lactate or lactic acid (3.) carbon dioxide
(4.) ADP (5.) oxygen
50. During respiration in a eukaryotic cell, the electron transport chain
is located in or on the (1.) cytosol (2.) matrix of the mitochondrion
(3.) cristae of the mitochondrion (4.) intermembrane space of the
mitochondrion (5.) none of the previous
51. The enzyme ATP synthase forms ATP (1.) due to the potential energy
of a concentration gradient of hydrogen ions across a membrane
(2.) due to substrate-level phosphorylation (3.) from glucose in the
absence of oxygen (4.) in the absence of chemiosmosis
52. In the Krebs cycle, the energetic production per glucose molecule is
(1.) 2 ATP, 6 NADH, 2 FADH2 (2.) 38 ATP
(3.) 4 ATP, 8 NADH
(4.) 2 ATP, 6 NADH (5.) ATP, 3 NADH, 1 FADH2
53. A major reason pH can affect enzyme activity because
(1.) most substrates don't function well at high or low pH
(2.) high or low pH may disrupt hydrogen bonding and change the
shape of the active site (3.) high or low pH may cause the active
site to lose its energy (4.) excess hydrogen ions can combine
with the substrate and cause the reaction to go more slowly
(5.) hydrogen ions absorb energy and thus there may not be
enough energy to get the reaction started.
54.
(1.)
(2.)
(3.)
(4.)
(5.)
Which chemical components make up a nucleotide?
a nitrogenous base, an amino acid, and a pentose sugar
a nitrogenous base, an amino acid, and a phosphate group
a nitrogenous base, a phosphate group, and a pentose sugar
a nitrogenous base, a fatty acid, and an amino acid
a series of nitrogenous bases and a sugar-phosphate backbone
55. Which level of protein structure are best represented by the alpha
helix and pleated beta sheet? (1.) primary structure (2.) secondary structure
(3.) tertiary structure (4.) quaternary structure (5.) pentiary structure
56. Estrogen, progesterone, and testosterone belong to which class
of molecules? (1.) proteins (2.) amino acids (3.) lipids
(4.) carbohydrates (5.) nucleic acids
57. What is meant by the induced fit of an enzyme?
(1.) The substrate can be altered so it is induced to fit into the enzyme's
active site. (2.) The enzyme is altered so it is induced to fit many
different types of substrate. (3.) Several sites on an enzyme can be
induced to act on a substrate. (4.) The enzyme changes its shape
slightly as it binds to the substrate. (5.) All of the above are
correct statements about the induced fit.
58. A competitive inhibitor competes with the __________ at the __________
of an enzyme. (1.) product ... active site (2.) product ... allosteric site
(3.) substrate ... active site (4.) substrate ... allosteric site
(5.) substrate ... active site and allosteric site
59. Water is a polar molecule. This means that (1.) the opposite ends of
the molecule have opposite charges (2.) water molecules are linear, like
a pole (3.) water is one of the many hydrophobic molecules (4.) the atoms
in water have equal electronegativities (5.) all of the above
60. Water resists temperature change because (1.) large bodies of
water cannot store heat (2.) heating water absorbs energy by
disrupting the hydrogen bonds before evaporation can occur
(3.) evaporation of water heats the surface it leaves
(4.) hydrogen bonding increases water's ability to vaporize
(5.) none of the above
61. That coastal climates are more moderate than inland climates
is due primarily to water's high (1.) heat of fusion
(2.) surface tension (3.) density (4.) heat of vaporization (5.) specific heat
62. The fatty acid tail of a phospholipid is ___________ because it ___________.
(1.) hydrophobic ... dissolves easily in water (2.) hydrophobic ... has no
charges to which water molecules can adhere (3.) hydrophilic ... consists
of units assembled by dehydration synthesis (4.) hydrophilic ... is
easily hydrolyzed into its monomers (5.) hydrophobic ... consists of
units assembled by dehydration synthesis
63. The overall three-dimensional shape of a polypeptide is called the
(1.) double helix (2.) primary structure (3.) secondary structure
(4.) tertiary structure (5.) quaternary structure
64. If an intestinal cell in a chimpanzee contains 48 chromosomes,
how many chromosomes would a chimpanzee sperm cell would
contain? (1.) 3 (2.) 6 (3.) 12 (4.) 24 (5.) 48
65. The region of a chromosome holding the two double strands of
replicated DNA together is called (1.) chromatin (2.) a centriole
(3.) a centromere (4.) a chromatid (5.) an aster
66. DNA replication occurs in (1.) prophase of both mitosis and
meiosis (2.) metaphase of meiosis only (3.) the S phase of interphase
in both somatic and reproductive cells (4.) the G1 phase of
interphase in reproductive cells only (5.) the cytokinesis portion of the
cell's life cycle
67. Which is NOT a property of water? (1.) Water is an excellent solvent.
(2.) Water has a high heat capacity. (3.) Water has a low surface tension.
(4.) Water has cohesive properties. (5.) As water freezes it becomes less
dense than when
in its liquid form.
68. An amino acid is characterized by which of the following functional
groups?
(1.) amino and hydroxyl (2.) amino and amino (3.) amino and aldehyde
(4.) amino and carboxyl (5.) carboxyl and keto
69. At which phase of the cell cycle does DNA replication occur?
(1.) G0 (2.) G1 (3.) S (4.) G2 (5.) M (6.) none of the previous
70. In decreasing the activation energy for a given reaction, enzymes
(1.) increase the likelihood that molecules involved will collide and form
products
(2.) decrease the likelihood that molecules involved will collide and form
products
(3.) have no effect on the rate of product formation in a given reaction
(4.) increase the concentration of the substrate
(5.) increase the activation energy for a given reaction
71. Mitosis occurs in all the following life cycle events EXCEPT (1.) gamete
formation
(2.) body cell replacement (3.) development (4.) growth (5.) wound healing
72. When a homozygous recessive organism is crossed with a heterozygous
dominant
organism, what percentage of the progeny will be heterozygous dominant?
(1.) 0%
(2.) 25% (3.) 50% (4.) 75% (5.) 100%
73. A reaction is regulated by regulating its enzyme. In competitive inhibition
(1.) An enzyme becomes more receptive to additional substrate molecules
after one
substrate molecule attaches to an active site. (2.) The inhibitor binds to an
enzyme at
locations other than an active or allosteric site. (3.) An end product of a
series of reactions
acts as an allosteric inhibitor, shutting down one of the enzymes catalyzing
the reaction
series. (4.) The inhibitor changes the shape of the enzyme which disables its
enzymatic activity.
(5.) A substance that mimics the substrate inhibits an enzyme by occupying
the active site.
74. Which is NOT a property of water? (1.) It has a low heat of vaporization.
(2.) It expands when
it freezes. (3.) It is a useful solvent. (4.) It has cohesive properties. (5.) It
resists changes in
temperature better than most other substances.
75. The primary value of a specific type of backcross known as the test cross
is to
(1.) determine whether a trait is really hereditary (2.) permit detection of
recessive genes
(3.) reveal cases of blending inheritance (4.) reveal remote ancestors
(5.) reveal sex linked inheritance
76. A plant that has a stem with scattered vascular bundles, leaves with
parallel venation,
and seeds with a single cotyledon is probably a (1.) bean plant (2.) moss (3.)
pine
(4.) corn plant (5.) liverwort
77. In corn, the trait for tall plants (T) is dominant to the trait for dwarf plants
(t)
and the trait for colored kernels (C) is dominant to the trait for white kernels
(c).
In a particular cross of corn plants, the probability of the offspring being tall is
1/2
and the probability of a kernel being colored is 3/4. Which of the following
most
probably represents the parental genotypes? (1.) TtCc X ttCc (2.) TrCc X TtCc
(3.) TtCc X ttcc (4.) TTCc X ttCc (5.) TTCc X TtCc
78. A form of vitamin-D resistant rickets, known as hypophosphatemia, is
inherited as an
X-linked dominant trait. If a male with hypophosphatemia marries a normal
female, which
prediction concerning their potential progeny would be true? (1.) All the sons
would inherit
the disease. (2.) All the daughters would inherit the disease. (3.) About 50%
of the sons would
inherit the disease. (4.) About 50% of the daughters would inherit the
disease. (5.) None of
the daughters would inherit the disease.
79. The end products of the light-dependent reactions of photosynthesis are
(1.) ADP, water, NADPH2 (2.) ADP, PGAL, RuBP (3.) ATP, CO2, water
(4.) ATP, NADPH2, O2 (5.) CO2, H+, PGAL
80. The cytoplasmic channels between plant cells which are most similar to
gap junctions
between animal cells are called (1.) middle lamellas (2.) tonoplasts (3.)
plasmodesmata
(4.) tight junctions (5.) desmosomes
Questions 81-83 refer to the diagram which appears below.
81. Which
statement
about this
system is
correct? (1.) It
is an important
component of
glycolysis,
which can not
function
without this
system. (2.) It
takes place in
an organelle
which has a
double
membrane.
(3.) It is unique
to an animal
cell. (4.) It is
unique to
bacteria. (5.) It
functions most
efficiently in
organisms
growing under
anaerobic
conditions.
82. Which is
the most
important
consequence of
the operation of
the system?
(1.) Coenzymes
are reduced.
(2.) Carbon
dioxide is
produced.
(3.) The pH of
the
mitochondrial
matrix
decreases. (4.)
Electron
carriers in the
mitochondrial
membrane are
irreversibly
oxidized. (5.)
An
electrochemical
(proton)
gradient is
formed.
83. A system
similar to that
depicted in this
figure can also
be found in the
(1.) Golgi
apparatus (2.)
lysosome
(3.) rough
endoplasmic
reticulum
(4.) chloroplast
(5.) ribosome
84. Which statement concerning leaf anatomy is FALSE? (1.) The cuticle is
composed of waxes
and prevents water loss. (2.) The stomata allow gas diffusion. (3.) The
mesophyll contains chlorophyll.
(4.) The palisade layer is adjacent to the lower epidermis.
Matching Section: For questions 85-87 choose the number of
the term that BEST matches each statement:
(1.) Xylem (2.) Epidermis (3.) meristem (4.) Phloem (5.) Cortex
-------------------------------------------------------------------------------------------------------------------------------------------------------------------85. These cells are responsible for the transport of food.
86. These cells serve as protection for roots, stems, and leaves.
87. These cells are mitotically active and also produce hormones.
88. The cuticle of plant cells: (1.) supports xylem and phloem tubes
(2.) is secreted by the cell wall (3.) is specialized for reproduction
(4.) waterproofs the epidermal cells
Use the following information to answer questions 89 through 91 .
A blood cell is placed in pure distilled water solution.
89. The blood cell would probably
(1.) expand and burst open (2.) Shrivel up
(3.) retain its normal shape (4.) lose its salt content
90. The concentration of water in this example is
(1.) greater inside the cell than outside
(2.) greater in the immediate environment than in the cell
(3.) equal inside and outside the cell
(4.) not important to the size of the cell
91. In this example, the environment is _____to the cell.
(1.) hypertonic (2.) hypotonic (3.) isotonic
92. The structure that pulls chromatids toward opposite poles
is called the (1.) centrosome (2.) spindle
(3.) kinetochore (4.) equatorial plate
93. Chromosomes in human skin are
(1.) haploid in number (2.) diploid in number
(3.) occur as homologous pairs during meiosis
(4.) all the previous choices are correct depending
upon whether mitosis or mitosis is occurring in
these cells
94. The stage in mitosis when the chromosomes
line up down the middle is (1.) interphase
(2.) prophase (3.) metaphase (4.) anaphase (5.) telophase
95. The main purpose of mitosis is to get daughter cells that
(1.) are identical to the parent cell (2.) have half the number of chromosomes
as the parent cell
(3.) get genetic diversity (4.) are able to adapt
Matching Section: For questions 96 through 100, choose the
choice from the list below which best describes each statement.
(1.) chloroplast (2.) cytosol (3) cell membrane
(4.) ribosome (5.) mitochondria
-------------------------------------------------------------------------------------------------------------------------------------------------------96. Site of protein synthesis
97.
98.
99.
100.
liquid part of the cell
where an energy conversion from glucose sugar occurs
where photosynthesis occurs
allows material in and out of the cell
101. The following functions of the smooth ER are correct EXCEPT:
(1.) Ca++storage for muscle contraction
(2.) adds hydroxyl group to chemicals to speed
their removal from the body (3.) involved in protein synthesis
(4.) detoxifies poisons (5.) functions in carbohydrate metabolism
Matching Question: Use the choices listed below to assist you in answering
questions 102-105 which follow.
(1.) centriole (2.) lysosome (3.) nucleolus (4.) peroxisome (5.) ribosome
----------------------------------------------------------------------------------------------------------------------------- ----------------------------------102. Found in both prokaryotic and eukaryotic cells.
103. Possesses a microtubule structure similar in form to a basal body.
104. Assembles ribosomal precursors.
105. Contains hydrolytic enzymes associated with the intracellular digestion
of macromolecules.
106. To overcome an energy barrier between reactants and products, energy
must be provided to
get the reaction started. This energy, which is recovered as the reaction
proceeds, is called:
(1.) activation energy (2.) initiation energy (3.) reaction energy
(4.) kinetic energy (5.) potential energy
107. Identical twins were born with genes for a genetic disorder that can be
controlled by
diet. Both twins were placed on this diet, which excludes a certain
amino acid.
However, one twin chose not to follow the diet and developed the genetic
disorder. The
other twin followed the diet and did not develop the disorder. This
difference between
the twins illustrates that (1.) gene expression is not influenced by
biochemical factors
(2.) gene expression is influenced by the environment (3.) identical twins
do not always
have the same genotype (4.) the genetic disorder is inherited by identical
twins, only
108. In the presence of alcohol dehydrogenase, the rate of reduction of
acetaldehyde to ethanol increases as you increase the concentration of
acetaldehyde. Eventually the rate of the reaction reaches a maximum, where
further increases in the concentration of acetaldehyde have no effect. Why?
(1.) all of the alcohol dehydrogenase molecules are bound to acetaldehyde
molecules (2.) at high concentrations of acetaldehyde, the activation energy
of the reaction decreases (3.) the enzyme is no longer specific for
acetaldehyde (4.) at high concentrations of acetaldehyde, the change in free
energy of the reaction decreases
109. In humans, the gene for red hair and the gene for freckles are often
inherited together
because both genes are located on the same chromosome. This
observation best illustrates
the concept of (1.) gene linkage (2.) dominance (3.) independent
assortment
(4.) hybridization
Note that question 110 has only three choices.
110. Which statement best describes the relationship between the number of
genes and number
of chromosomes in human skin cells? (1.) There are more genes than
chromosomes in
skin cells. (2.) There are more chromosomes than genes in skin cells.
(3.) There are an
equal number of chromosomes and genes in skin cells.
111. A woman has a gene that causes a visual disorder. To prevent the gene
from appearing in
future generations, the defective gene would have to be repaired in the
mother's
(1.) eye (2.) uterus (3.) nervous system (4.) reproductive cells
112. How many times as efficient is aerobic respiration compared to
anaerobic respiration? (1.) 2X (2.) 10X
(3.) 18X (4.) 36X
113. The greatest amount of energy is released by the (1.) oxidation of glucose
to lactic acid (2.) conversion of carbon dioxide and water to glucose (3.)
conversion of glucose to pyruvic acid (4.) oxidation of glucose to carbon
dioxide and water
114. The complete hydrolysis of carbohydrates usually results in the
production of (1.) carbon dioxide (2.) simple sugars (3.) glycogen (4.) urea
115. Which substances are commonly used as the building blocks in the
synthesis of some proteins? (1.) sugars (2.) amino acids (3.) fatty acids and
glycerol (4.) amino acids and glycerols
116. Which group of organic compounds includes the enzymes? (1.) proteins
(2.) starches (3.) carbohydrates (4.) lipids
117. A hydrolysis reaction occurs when (1.) two simpler molecules are
combined and water is split out in the reaction (2.) a complex molecule is split
into simpler molecules by the addition of water (3.) one element is exchanged
for another in a compound (4.) fats are formed from smaller organic molecules
118. In what part of the cell does glycolysis take place?
(1.) Cytosol (2.) Mitochondria (3.) Golgi apparatus (4.) ER
119. How many molecules of ATP are produced during glycolysis (the net gain
of ATP molecules)?
(1.) 1 (2.) 2 (3.) 12 (4.) 24
120. Which phrase best matches the definition of the term hydrophobic?
(1.) "water-hating" (2.) "water-loving" (3.) "water-impartial" (4.) "waterstoring"
121. The cytoskeleton is primarily responsible for __________.
(1.) Cell shape (2.) Cellular energy (3.) Cellular respiration (4.) Cell density
122. Membrane transport is important for which of the following biological
processes?
(1.) Protein synthesis (2.) Cell communication (3.) Maintenance of cellular pH
(4.) All of the above
123. In which aquatic environment would you expect dissolved oxygen to be
highest?
(1.) A mountain lake that is clear and cold (2.) A bog where the water is
shallow and
warm and there is a mat of aquatic plants (3.) A marine tidepool
(4.) A cold mountain stream dropping over a series of small rock falls
(5.) A coral reef in a still lagoon
Use the information below and your knowledge of biology to do question 124.
A student wanted to study the effect of nitrogen fertilizer on plant growth, so
she took two similar plants and set them on a window sill for a two-week
observation period. She watered each plant the same amount, but she gave
one a small dose of fertilizer with each watering. She collected data by
counting the total number of new leaves on each plant and also measured the
height of each plant in centimeters.
124. Which is a significant flaw in this experimental set-up?
(1.) There is no variable factor. (2.) There is no control.
(3.) There is no repetition. (4.) Measurable results cannot be expected.
(5.) It will require too many days of data collection.
125. What is the role of KOH in our cell respiration experiment?
(1.) It serves as an electron donor to promote cellular respiration.
(2.) As KOH breaks down, the oxygen needed for cellular respiration is
released.
(3.) It serves as a temporary energy source for the respiring organism.
(4.) It binds with carbon dioxide to form a solid, preventing CO2 production
from affecting gas volume.
(5.) Its attraction for water will cause water to enter the respirometer.
126. Which statement is correct?
(1.) Crossing over occurs in prophase I of meiosis and metaphase of mitosis.
(2.) DNA replication occurs once prior to mitosis and twice prior to meiosis.
(3.) Both mitosis and meiosis result in daughter cells identical to the parent
cells.
(4.) Karyokinesis occurs once in mitosis and twice in meiosis.
(5.) Synapsis occurs in prophase of mitosis.
127. The cell cycle in a certain cell type has a duration of 16 hours.
The nuclei of 660 cells showed 26 cells in anaphase.
What is the approximate duration of anaphase in these cells?
(1.) 2 minutes
(2.) 13 minutes
(3.) 19 minutes
(4.) 38 minutes
(5.) 647 minutes
The following are results from an experiment involving a fungus and crossing
over.
Number of Asci Counted in Sordaria/ Spore Arrangement
7
8
3
4
1
2
4
4
2
2
2
2
light/4
dark/4
light/2
dark/2
dark/4
light/4
dark spores
light spores
dark/2 light/2 dark spores
light/2 dark/2 light spores
light/2 dark spores
dark/2 light spores
128. How many of these asci contain a spore arrangement that resulted from
crossing over?
(1.) 3
(2.) 7
(3.) 8
(4.) 10
(5.) 15
129. Which statement describes the currently accepted theory of how an
enzyme and its substrate fit together?
(1.) As the product is released, the enzyme breaks down.
(2.) The enzyme is like a key that fits into the substrate, which is like a lock.
(3.) The active site is permanently changed by its interaction with the
substrate.
(4.) As the substrate binds to the enzyme, the shape of the enzyme site
changes to accommodate the reaction.
130. In noncompetitive inhibition, the allosteric inhibitor
(1.) attaches to the active site, preventing the substrate from attaching there.
(2.) attaches to the substrate, preventing it from attaching to the active site.
(3.) changes the pH of the environment, thus preventing enzyme-substrate
complex formation.
(4.) causes the substrates to polymerize, preventing individual enzymesubstrate attachment.
(5.) attaches to the enzyme at a site away from the active site, altering the
shape of the enzyme.
131. In competitive inhibition, the allosteric inhibitor
(1.) attaches to the active site, preventing the substrate from attaching there.
(2.) attaches to the substrate, preventing it from attaching to the active site.
(3.) changes the pH of the environment, thus preventing enzyme-substrate
complex formation.
(4.) causes the substrates to polymerize, preventing individual enzymesubstrate attachment.
(5.) attaches to the enzyme at a site away from the active site, altering the
shape of the enzyme.
132. Which is most similar to the process of competitive inhibition? (1.)
When you are about to park your car in your spot, a bulldozer comes along and
smashes your car away from the spot. (2.) When you arrive at work in the
morning, you are unable to park your car in your assigned parking spot
because someone has placed a giant cement block in front of your spot. (3.)
When you arrive at work in the morning, you are unable to park your car in
your assigned parking spot because the car of the person next to you has
taken up just enough space that you can not fit your own car in. (4) When you
arrive at work in the morning, you are unable to park your car in your parking
spot, because someone with a car exactly like yours has already taken your
spot, leaving you nowhere to park your car.
Base your answers to questions 133 and 134 below on the reading passage
that follows and your knowledge in biology. A student ground 1 gram of fresh
liver in a mortar, placed the ground liver in a test tube, and added 1 ml of
peroxide. The gas that was generated was collected. A glowing splint burst
into flames when placed in the gas. The student then repeated the procedure,
using one gram of boiled liver and one gram of liver treated with a strong acid.
When peroxide was added to each sample of liver, no gas was generated.
133. The gas that was generated was most likely (1.) oxygen (2.) nitrogen (3.)
carbon dioxide (4.) hydrogen (5.) ammonia (6.) water vapor
134. If the substance in the liver that acted on the peroxide was an enzyme, it
could (1.) be recovered from the living tissue that had not been boiled or
treated with acid after the reaction ceased (2.) not be recovered because it
was consumed while engaging in its catalytic reaction activities (3.) not be
recovered because there is no enzyme in liver that catalyzes the breakdown of
peroxide (4.) not be recovered because grinding would break up the molecule
(5.) be recovered only before the peroxide was added
135. Which one of the following has a carboxyl group? (1.) R–NH2 (2.) R–SH
(3.) R–OH (4.) R-COOH
136. Which one of the following is a weak acid? (1.) R–PO4
R–OH (4.) R-COOH
(2.) R–SH
(3.)
137. Which one of the following has an amino group? (1.) R–NH2 (2.) R–SH
(3.) R-COOH (4.) R–OH
138. Which one of the following has a sulfhydryl group? (1.) R–NH2 (2.) R–SH
(3.) R-COOH (4.) R–OH
139. Some substances, such as oil and gasoline, will not dissolve in water
because
(1.) their molecules are so large (2.) their molecules have no charges or
partial charges to
which water molecules can adhere (3.) they do not ionize (4.) their
electrons are so stable that they
do not exchange with water molecules (5.) oil and gasoline are inorganic
compounds
140. From your knowledge of organic chemistry, you would predict that an
abscisic acid (ABA)
molecule has a(n) __________ group. (1.) carboxyl (2.) hydroxyl (3.)
carbonyl
(4.) amino (5.) sulfhydryl
141. The majority of ATP molecules derived from nutrient metabolism are
generated by (the):
(1.) anaerobic fermentation and glycolysis (2.) fermentation and electron
transport chain
(3.) glycolysis and substrate phosphorylation (4.) Krebs cycle and electron
transport chain
(5.) substrate phosphorylation
142. What is the molecule illustrated above?
(1.) a polyunsaturated triglyceride
(2.) an unsaturated fatty acid
(3.) likely to be a common component of plant proteins
(4.) saturated fatty acid (5.) similar in structure to a steroid
143. Which process would include a net movement of sugar molecules through
a membrane from a region of higher concentration to a region of lower
concentration? (1.) osmosis (2.) cyclosis (3.) passive transport (4.) active
transport
144. In the human body, the potassium ion can pass easily through cell
membranes, yet the potassium ion concentration is higher inside many cells
than it is outside these cells. This condition is mainly a result of the process
of (1.) passive transport (2.) active transport (3.) osmosis (4.) pinocytosis
145.The primary function of root hairs in a plant is to
(1.) prevent excessive loss of water
(2.) provide increased surface area for absorption
(3.) conduct water and minerals upward
(4.) conduct organic food materials upward and downward
146. Which compounds are produced in human muscle cells as a result of the
oxidation of glucose in the absence of oxygen? (1.) lipase and water (2.)
sucrase and carbon dioxide (3.) ethyl alcohol and ATP (4.) lactic acid and ATP
147. Most animals make energy available for cell activity by transferring the
potential energy of glucose to ATP. This process occurs during (1.) aerobic
respiration, only (2.) anaerobic respiration, only (3.) both aerobic and
anaerobic respiration (4.) neither aerobic nor anaerobic respiration
148. The largest number of cells in a group of onion root tip cells would be
found in (1.) the M stage
(2.) Interphase (3.) G1 (4.) the S stage (5.) metaphase (6.) in G7
149. Alcohol fermentation and aerobic respiration are similar in that both
processes (1.) utilize light
(2.) produce ethyl alcohol (3.) require free oxygen (4.) release carbon dioxide
150. The net flow of materials through the membrane of a cell against a
concentration gradient is known as (1.) passive transport (2.) active transport
(3.) osmosis (4.) pinocytosis
Do the following essays.
1. Membranes are important structural features of cells.
(a.) Describe how membrane structure is related to the transport of
materials across a membrane.
(b.) Describe the role of membranes in the synthesis of ATP in respiration.
2. Describe the essential features of an experimental apparatus that
could be used to measure oxygen consumption by a small organism.
List at least four of these features of the apparatus (not including
the organism). Explain why each of these features is necessary.
3.
Enzymes are biological catalysts.
(a.) Relate the chemical structure of an enzyme to its specificity.
(b.) Design a quantitative experiment to investigate the influence of
pH on enzyme activity. Include a problem, hypothesis, and procedure.
4. List 5 properties of water associated with hydrogen bonding and explain
why these properties are essential to living things.
5. (a.) Explain the processes resulting in genetic variability in an
organism due to meiotic cell division. Use the terms synapsis,
tetrad, crossing over, and variability correctly in your explanation.
(b.) Explain how the meiotic process discussed above drive the process
of natural selection.
6. How can carbohydrate, neutral lipids, and proteins usually be
distinguished based
on their molecular formulae?
7. An AP Biology student prepared solutions of 0.8 M, 0.6 M, 0.4 M, and 0.2 M
sucrose, but forgot to label them. After realizing the error, the student
randomly labeled the flasks containing these four unknown solutions as flask
A,
flask B, flask C, and flask D. Design an experiment, based on the principles
of diffusion and osmosis, that the assistant could use to determine which of
the flasks contains each of the four unknown solutions.
Include in your answer:
(a) a description of how you would set up and perform the experiment
(b) the results you would expect from your experiment
(c) an explanation of those results based on the principles involved. (include
terms
like direction of osmosis as well as terms which describe relative
concentration
in this explanation)
8. Some researchers have proposed that doing 50 jumping jacks prior to
squeezing a clothespin will increase the rate that that individual can squeeze
a clothespin in one minute. Other researchers dispute this claim.
a.) Using the correct format for stating a hypothesis, correctly state a
hypothesis for this experiment.
b.) What is the independent variable in this experiment?
c.) What is the dependent variable in this experiment?
d.) What is the control in this experiment?
9. Explain how the addition of the following influences the rate of most
enzyme controlled reactions in living systems
and explain HOW and WHY.
a.)
b.)
c.)
d.)
e.)
increase in temperature over 50 C
adding concentrated sulfuric acid
adding more substrate to a fixed amount of enzyme
the addition of a competititive inhibitor
the addition of a noncompetitive inhibitor
10. (a.) List two advantages C-4 metabolism appears to have over C-3
photosynthesis metabolism
in plants.
(b.) List an advantage and a disadvantage of CAM metabolism in those
plants utilizing
this method.
11. The cell is a unit of biological activity that is delimited by a
semipermeable membrane and is
capable of self-reproduction in a medium free from other living systems.
"Plastids
and mitochondria were originally free-living prokaryotes that early in
evolution that took up
residence inside eukaryotic cells."
(a.) Describe the structure of both the chloroplast and mitochondrion. State
the function
of each in the cell with particular reference to what goes on where.
(b.) Describe the evidence that supports the quote above.
12. Identify all the numbered structures on the cross section of the plant leaf
below and state their functions.
http://www.ekcsk12.org/science/apbio/practicemidterm2005-2006.html
Multiple Choice/Matching Section
1.
2.
3.
4.
5.
6.
7.
8.
4
4
3
4
2
2
5
2
9. 3
10.
11.
78.
79.
80.
81.
82.
83.
84.
2
3
5
4
3
2
5
4
4
12. 1
13. 3
14. 1
15. 4
16. 4
17. 1
18. 4
19. 3
20. 1 (although ribosomes
on their surface do # 5)
21. 5
22. 3
89. 1
100. 3
90. 2
101. 3
91. 2
102. 5
92. 2
103. 1
93. 2
104. 3
94. 3
105. 2
95. 1
106. 1
23.
24.
25.
26.
27.
28.
29.
30.
5
3
3
2
1
2
6
2
31. 5
32. 5 (or conceivably 1)
33. 5
111. 4
122. 4
112. 4
123. 4
113. 4
124. 3
114. 2
125. 4
115. 2
126. 4
116. 1
127. 4
117. 2
128. 4
34.
35.
36.
37.
38.
39.
40.
41.
2
5
4
5
2
3
1
4
45.
46.
47.
48.
49.
50.
51.
52.
1
1
2
1
2
3
1
1
56.
57.
58.
59.
60.
61.
62.
63.
3
4
3
1
2
5
2
4
67.
68.
69.
70.
71.
72.
73.
74.
3
4
3
1
1
3
5
1
42. 4 53. 2 64. 4 75. 2
43.
44.
133.
134.
135.
136.
137.
138.
139.
1 54. 3 65. 3 76. 4
2 55. 2 66. 3 77. 1
1
144. 2
1
145. 2
4
146. 4
4
147. 3
1
148. 2
2
149. 4
2
150. 2
85.
86.
87.
88.
4
2
3
5
96. 4
97. 2
98. 5
99. 1
107.
108.
109.
110.
2
1
1
1
118. 1
119. 2
120. 1
121. 1
129.
130.
131.
132.
4
5
1
4
140.
141.
142.
143.
1
4
2
3
1. (a.) Membrane Structural features:
Phospholipid structure - hydrophilic end
with phosphate with a pair of hydrophobic
hydrocarbon tails -- contains two
phospholipid bilayers
-- is fluid mosaic description with
proteins embedded in the membrane
used for transport -- sterols are also
embedded in the membrane Welllabeled diagram with description of
functions may replace this description.
Membrane function: Use the term "selectively permeable" or a good definition of
selective permeability or an explanation of the role of phospholipids or proteins
including pore proteins in determining selective permeability. Essay must
include a description of the effect of size, charge, etc.on membrane
permeability. Passive transport or diffusion / osmosis must be related to the
concentration gradient on both sides of the membrane. Ion transport may be
mentioned in reference to channel: transport as a mechanism for a change in
permeability. At least one other terms which must be defined for full credit
include facilitated diffusion, active transport, exocytosis, endocytosis,
phagocytosis, and pinocytosis.
(b.) Role of the Membrane in the Production of ATP in Respiration:
Chemiosmosis: -- Involved molecules such as electron transport molecules are
embedded
in the membrane in a sequentially organized manner
The energy comes from the flow of electrons to establish a H+ / Proton / pH
gradient
Movement through the membrane generates ATP
A specific protein makes ATP (ATP synthase) through an F-0-F-1 complex
2. Some features of a
respirometer (my apology
for the crude paintbrush
drawing) include:
1 = pipette which measures
the oxygen consumption by
the organism
2 = stopper and sealant
which prevent water and
gases from leaking into the
respirometer
3 = organism (consuming
oxygen and releasing CO2
... can't be part of the
answer)
4 = cotton which separates
the caustic KOH from the
organism
The unlabled line at the
bottom is pointing to the
KOH which absorbs the
CO2 released by the
organism so it doesn't
cancel out the consumption
of oxygen into the pipette
and respirometer
3. (a.) The structure of an enzyme influences its catalytic activity. The enzyme
has a specific 3-D shape/ or tertiary structure which allows it to fit with a specific
substrate. The active site or the enzyme contains a groove or pocket which has
a special shape for substrate. This model of enzyme structure and function is
called the "lock and key" and model. Some factors such as cofactors, allosteric
interactions, or inhibitors change to the enzyme's shape to allow it or in some
cases not allow it to fit with the substrate. Many enzymes can slightly change
their shape to fit the substrate which is called the induced fit theory. Enzymes
speed chemical reactions by lowering the activation energy needed to start the
chemical reaction.
(b.) Problem: How does pH influence enzyme activity?
Hypothesis: Very strong acids or bases prevent enzymes from functioning.
[Procedure]
-- put 10 ml of an acid of pH 4 in one test tube, 10 ml of distilled water in another
test tube,
and 10 ml of a base of pH 10 in another test tube
-- make certain that conditions such as temperature, size of the test tubes,
cleanliness of the
test tubes, etc. are the same for all test tubes
-- put one ml of an enzyme in each solution
-- observe the rate of chemical reaction (bubbling, color change, etc. in each test
tube and record
(control -- water solution, independent variable -- solution pH, dependent variable
-- reaction activity)
4.
Some possible answers:
polarity -- unequal charge distribution
-- causes hydrogen bonding
adhesion -- caused by unequal charges
-- attraction for unlike substance
cohesion -- attraction between water molecules -- due to hydrogen bonding -- produces
surface thension of water striders walking
capillary action -- water rises in tubes of narrow diameter leading to transpiration
high specific heat -- allows water to change temp slowly and moderate climate
high boiling point -- organisms don’t boil away -- good evaporative coolant
imbibition --- water soaks into other substances due to its hydrogen bonding -- such as
seeds
-- Most dense at 4 C (ice floats and results in thermal overturn mixing oxygen and
nutrients in water)
Water is a stable compound -- used in metabolic reactions
Water is a good conductor when electrolytes are mixed in it (electric eel ,etc.)
Water is not compressible --- results in blood pressure, etc
5.. The meeting of two pair of homologous chromosomes in prophase I of
meiosis I is called synapsis.
The two pair of homologous chromosomes are
called a tetrad. These chromosomes wrap around each other and exchange
pieces in a process called crossing over.
This means the new chromosome
combinations formed in the gametes formed in meiosis will be different from the
original chromosome combinations.
This variation in the chromosomes means
that the offspring formed in sexual reproduction will exhibit variations.
These variations may produce organisms which are better able to better
survive a change in the environment. This process is called survival of the
fittest. The entire process where a variation of a species survives and adapts
while another does not and is removed from the population is called natural
selection.
6. Both neutral lipids and carbohydrates have carbon, hydrogen, and oxygen in
their structure. In carbohydrates the ratio of hydrogen
to oxygen is 2:1, while it is in excess of this in a neutral lipid. Proteins have in
addition to the previous three elements nitrogen in their structure.
7. (a) a description of how you would set up and perform the experiment
Set up must include:
all four solutions (1)
a way of comparing them and what they will do (either a standard dialysis bag or
solution
outside varying bags) (1)
a set up which clearly implies the student is testing an osmotic situation
(b) the results you would expect from your experiment
-- to get credit the student must show that the greater the difference in
concentration
from the dialysis bag, the greater the rate of osmosis
(c) an explanation of those results based on the principles involved. (include
terms
like direction of osmosis as well as terms which describe relative concentration in
this explanation)
-- direction of osmosis clearly implied
-- hypertonic (or greater concentration of solute/or lesser solvent)
-- hypotonic (or lesser concentration of solute/or greater solvent)
8. (a.) If I exercise by doing jumping jacks prior to squeezing the clothespin,
then the rate of clothespin squeezing will increase. (Note that the hypothesis is
properly stated as an if .. then statement relating the independent and dependent
variables together.)
(b.) Exercising before squeezing the clothespin is the independent variable.
(c.) The dependent variable is the number of clothespin squeezes in one minute.
(d.) The control in this experiment is clothespin squeezing without exercising
before hand.
9. (a.) An increase in temperature over 50 C will slow or stop reaction rate
because it denatures the enzyme.
(b.) Adding concentrated sulfuric acid will markedly slow the reaction rate,
because its ionic interactions
will denature the enzyme
(c.) Adding more substrate to a fixed amount of enzyme will increase the
reaction rate until all the enzyme
molecules are combined with all the substrate molecules, then the
reaction rate will level off, as adding
more substrate molecules can have no additional effect, as there are no
enzyme molecules to combine with.
(d.) The addition of a competititive inhibitor will occupy the active site of the
enzyme, thus slowing the
reaction rate of the enzyme.
(e.) The addition of a noncompetitive inhibitor to a site away from the active
site (allosteric site) will change
the overall shape of the enzyme molecule, including the active site, so
the enzyme does not function.
10.
(a.) C-4 plants are able to maximize photorespiration by using intense
sunlight more
efficiently to enhance sugar production.
(b.) Plants engaging in CAM metabolism are able to fix all the carbon
dioxide they use
in the form of organic acids at night. This allows these plants to close
their stomata
during the day to conserve water. A disadvantage is that by only
opening their
stomata at night, these plants have a slower rate of photosynthesis that
either
C-3 or C-4 plants.
11.
(a.) Both the chloroplast and mitochondrion contain an inner membrane in
addition to
their outer membrane. The inner membrane of the chloroplast or
thylakoid is where
the major events of the light dependent reactions of photosynthesis
occur. The dark
reactions of photosynthesis occur outside the thylakoids in the stroma
fluid of the
outer compartment. The inner membrane of the mitochondrion is
called the cristae.
The major events involving the electron transport chain and the
chemiosmotic
synthesis of ATP occur here in the process of cellular respiration.
(The actual
synthesis of ATP in this process occurs in the mitochondrial matrix.)
(b.) Both the mitochondria and chloroplasts contain their own DNA which is
independent
of the DNA in the nuclei of the cells they are found in. This circular
DNA is very
similar to that found in bacteria. The concept of serial endosymbiosis
states that
mitochondria and chloroplasts were small endosymbionts living in a
larger cell that
were eventually taken over by that cell. Chloroplasts and
mitochondria can replicate
independently in cells to this day by a process similar to binary fission
in bacteria.
Ribosomal RNA in chloroplasts and mitochondria are similar to that of
bacteria as well.
1 = cuticle -waterproofs
and protects
leaf
2 = upper
epidermis -water proofs
and protects
leaf
3 = palisade
mesophyll -where most
photosynthesis
occurs in dicot
leaves
4 = spongy
mesophyll -does most gas
exchange and
responsible
for some
photosynthesis
5 = vein (or
vascular
bundle) -contains the
conducting
tissue within
the leaf
(xylem and
phloem)
6 = lower
epidermis -waterproofs
and protects
leaf
7 = guard cell
-- opens and
closes stomate
8 = stomate -responsible
for regulating
gas exchange
and water loss
(transpiration)
from the leaf
http://www.ekcsk12.org/science/apbio/practicemidterm2005-2006answers.html