Category: Curriculum Map

Chapter 37 AP Objectives

 

Chapter 37     Nutrition in Plants
Objectives
Nutritional Requirements of Plants
1. Describe the ecological role of plants in transforming inorganic molecules into organic compounds.
2. Define the term essential nutrient.
3. Explain how hydroponic culture is used to determine which minerals are essential nutrients.
4. Distinguish between macronutrient and micronutrient.
5. Name the nine macronutrients required by plants.
6. List the eight micronutrients required by plants and explain why plants need only minute quantities of these elements.
7. Explain how a nutrient’s role and mobility determine the symptoms of a mineral deficiency.
The Role of Soil in Plant Nutrition
8. Define soil texture and soil composition.
9. Explain how soil is formed.
10. Name the components of topsoil.
11. Describe the composition of loams and explain why they are the most fertile soils.
12. Explain how humus contributes to the texture and composition of soils.
13. Explain why plants cannot extract all of the water in soil.
14. Explain how the presence of clay in soil helps prevent the leaching of mineral cations.
15. Define cation exchange, explain why it is necessary for plant nutrition, and describe how plants can stimulate the process.
16. Explain why soil management is necessary in agricultural systems but not in natural ecosystems such as forests and grasslands. Describe an example of human mismanagement of soil.
17. List the three mineral elements that are most commonly deficient in agricultural soils.
18. Explain how soil pH determines the effectiveness of fertilizers and a plant’s ability to absorb specific mineral nutrients.
19. Describe problems resulting from farm irrigation in arid regions.
20. Describe actions that can reduce loss of topsoil due to erosion.
21. Explain how phytoremediation can help detoxify polluted soil.
The Special Case of Nitrogen as a Plant Nutrient
22. Define nitrogen fixation and write an overall equation representing the conversion of gaseous nitrogen to ammonia.
23. Explain the importance of nitrogen-fixing bacteria to life on Earth.
24. Summarize the ecological role of each of the following groups of bacteria.
a. ammonifying bacteria
b. denitrifying bacteria
c. nitrogen-fixing bacteria
d. nitrifying bacteria
25. Explain why improving the protein yield of crops is a major goal of agricultural research.
Nutritional Adaptations: Symbiosis of Plants and Soil Microbes
26. Describe the development of a root nodule in a legume.
27. Explain how a legume protects its nitrogen-fixing bacteria from free oxygen, and explain why this protection is necessary.
28. Describe the basis for crop rotation.
29. Explain why a symbiosis between a legume and its nitrogen-fixing bacteria is considered to be mutualistic.
30. Explain why a symbiosis between a plant and a mycorrhizal fungus is considered to be mutualistic.
31. Distinguish between ectomycorrhizae and endomycorrhizae.
Nutritional Adaptations: Parasitism and Predation by Plants
32. Name one modification for nutrition in each of the following groups of plants:
a. epiphytes
b. parasitic plants
c. carnivorous plants
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Chapter 38 AP Objectives

Chapter 38     Plant reproduction and Development
Objectives
Sexual Reproduction
1. In general terms, explain how the basic plant life cycle with alternation of generations is modified in angiosperms.
2. List four floral parts in order from outside to inside a flower.
3. From a diagram of an idealized flower, correctly label the following structures and describe the function of each structure:
a. sepals
b. petals
c. stamen (filament and anther)
d. carpel (style, ovary, ovule, and stigma)
4. Distinguish between:
a. complete and incomplete flowers
b. bisexual and unisexual flowers
c. monoecious and dioecious plant species
5. Explain by which generation, structure, and process spores are produced.
6. Explain by which generation, structure, and process gametes are produced.
7. Name the structures that represent the male and female gametophytes of flowering plants.
8. Describe the development of an embryo sac and explain the fate of each of its cells.
9. Explain how pollen can be transferred between flowers.
10. Distinguish between pollination and fertilization.
11. Describe mechanisms that prevent self-pollination.
12. Outline the process of double fertilization. Explain the adaptive advantage of double fertilization in angiosperms.
13. Explain how fertilization in animals is similar to that in plants.
14. Describe the fate of the ovule and ovary after double fertilization. Note where major nutrients are stored as the embryo develops.
15. Describe the development and function of the endosperm. Distinguish between liquid endosperm and solid endosperm.
16. Describe the development of a plant embryo from the first mitotic division to the embryonic plant with rudimentary organs.
17. From a diagram, identify the following structures of a seed and state a function for each:
a. seed coat
b. proembryo
c. suspensor
d. hypocotyls
e. radicle
f. epicotyl
g. plumule
h. endosperm
i. cotyledons
j. shoot apex
18. Explain how a monocot and dicot seed differ.
19. Explain how fruit forms and ripens.
20. Distinguish among simple, aggregate, and multiple fruit. Give an example of each type of fruit.
21. Explain how selective breeding by humans has changed fruits.
22. Explain how seed dormancy can be advantageous to a plant. Describe some conditions for breaking dormancy.
23. Describe the process of germination in a garden bean.
Asexual Reproduction
24. Describe the natural mechanisms of vegetative reproduction in plants, including fragmentation and apomixis.
25. Explain the advantages and disadvantages of reproducing sexually and asexually.
26. Explain various methods that horticulturalists use to propagate plants from cuttings.
27. Explain how the technique of plant tissue culture can be used to clone and genetically engineer plants.
28. Describe the process of protoplast fusion and its potential agricultural impact.
Plant Biotechnology
29. Compare traditional plant-breeding techniques and genetic engineering, noting similarities and differences.
30. Describe two transgenic crops.
31. Describe some of the biological arguments for and against genetically modified crops.
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Chemistry of Organisms

Chemistry
All Materials © Cmassengale

Composition of Matter

Ø  Everything in the universe is made of matter

Ø  Matter takes up space & has mass

Ø  Mass is a measure of the amount of matter in the substance

Ø  Mass & weight are NOT the same

Ø  Weight is a measure of the pull of gravity on an object

Question: Is the mass of an object the same on the moon as it is on the Earth? Is its weight the same? (Hint: Gravitational pull on the moon is 1/6 of that on the Earth.)

Ø  Matter exists in 4 states – solid, liquid, gas, & plasma

Ø  Solids have both a definite volume & definite shape (rock)

Ø  Liquids have a definite volume but no definite shape; they can be    poured (water)

Ø  Gases do not have a definite volume or definite shape, but they take the  volume & shape of their container

Ø  Plasmas have no definite volume, no definite shape, and only exist at extremely high temperatures such as the sun

Ø  Chemical Changes in matter are essential to all life processes

Ø  Biologists study chemistry because all living things are made of the same kinds of matter that make up nonliving things

Elements

Ø     Elements are pure substances which cannot be chemically broken down into simpler kinds of matter

Ø     More than 100 elements have been identified, but only about 30 are important in living things

Ø     All of the Elements are arranged on a chart known as the Periodic Table

Ø     Periodic charts tell the atomic number, atomic mass, & chemical symbol for every element

Ø     Four elements, Carbon – C, Hydrogen – H, Oxygen – O, and Nitrogen – N make up almost 90% of the mass of living things

Ø     Every element has a different chemical symbol composed of one to two letters

Ø     Chemical symbols usually come from the first letter or letters of an element like C for Carbon and Cl for Chlorine

Ø     Some chemical symbols come form their Latin or Greek name such as  Na for Sodium (natrium) or K for Potassium (Kalium)

Ø      Elements in the same horizontal period on the periodic table have the same number of energy levels (e.g. H & He in period 1 have only a K energy level)

[Periodic Table]
All Period 2 elements have 2 energy levels
(K & L)

Ø      Elements in the same vertical Family on the periodic table have the same number of electrons in their outermost energy level & react similar (e.g. Family IV, the Carbon family all have 4 electrons in their outermost energy level)

Atoms

Ø     Atoms are the simplest part of an element that keeps all of the element’s properties

Ø     Atoms are too small to be seen so scientists have developed models that show their structure & properties

Ø     Atoms consist of 3 kinds of subatomic particles – protons & neutrons in the center or nucleus, and electrons spinning in energy levels around the center

Ø     The nucleus is the center of an atom where most of the mass is concentrated

Ø     Protons are positively charged ( p+ ),  have a mass of 1 amu (atomic mass unit) , are found in the nucleus, and determine the atomic number of the element

Example:  Carbon has 6 protons so its atomic number is 6

Ø     Neutrons are neutral or have no electrical charge (n), have a mass of 1 amu, are found in the nucleus, and when added to the number of protons, determine the atomic mass of the element

Example:  Sodium has 11 protons and 12 neutrons so its atomic mass is 11+12=23 amu

Ø     Electrons (e-) are negatively charged, high energy particles with little mass that spin around the nucleus in energy levels

Ø     Seven energy levels (K, L, M, N, O, P, & Q) exist around the nucleus and each holds a certain number of electrons

Ø     The K energy level is closest to the nucleus & only holds 2 electrons, while the  L – Q energy levels can hold 8 electrons  

Ø     Electrons in outer energy level are traveling faster & contain more energy than electrons in inner levels  

Ø     The number of protons (positive charges) and electrons (negative charges in an atom are equal so the net electrical charge on a atom is zero making it electrically neutral

Ø     Stable or non-reactive atoms have an outer energy level that is filled with electrons  

Compounds

Ø     Most elements do not exist by themselves; Most elements combine with other elements

Ø      Compounds are made of atoms of two or more elements chemically combined

Ø      Chemical Formulas represent a compound & show the kind & number of atoms of each element  (e.g. H2O has 2 hydrogen & 1 oxygen)

Ø      Compounds have different physical & chemical properties than the atoms that compose them  (e.g. hydrogen & oxygen are gases but H2O is a liquid)

Ø      The number & arrangement of electrons in an atom determines if it will combine to form compounds

Ø      Chemical reactions occur whenever unstable atoms (outer energy level not filled) combine to form more stable compounds

Ø      Chemical bonds form between atoms during chemical reactions

Types of Chemical Bonds

Ø     Covalent bonds form between atoms whenever they share 1 or more pairs of electrons (e.g. H2O)  

Ø     Molecules form from covalent bonding & are the simplest part of a compound (e.g. NaCl, H2O, O2)  

Ø     Ionic bonding occurs between a positively & negatively charged atom or ion  

Ø     Positively charged ions have more electrons (-) than protons (+); negatively charged ions have more protons than electrons

Ø     Table salt (NaCl) forms when the 1 outer electron of Na is transferred to the outer energy level of chlorine that has 7 electrons (e-)

Ø     Sodium (Na) with 1 less e- becomes positively charged, while Chlorine (Cl) with 1 more e- becomes negatively charged; the + and – charges attract & form the ionic bond holding NaCl together

Ø     Other types of chemical bonding include hydrogen bonding

Energy

Ø     Energy is the ability to do work

Ø     Energy occurs in several forms & may be converted from one form to another

Ø     Sunlight is the ultimate energy for all life on earth

Ø     Forms of energy include chemical, electrical, mechanical, thermal, light, & sound

Ø     Free energy is the energy available for work (e.g. cells have energy to carry out cell processes)

Ø     Cells convert the chemical energy stored in food into other types of energy such as thermal & mechanical

Ø     Energy is used to change matter form one state into another (e.g. liquid into a gas)

Chemical Reactions

Ø     Living things undergo thousands of chemical reactions

Ø     Chemical equations represent chemical reactions

Ø     CO2 + H20—–goes to—–H2CO3  (carbonic acid) is a sample Chemical Reaction in living things

Ø     Reactants are on the left side of the equation, while products are on the right side

Ø Activation energy is required to start many reactions

Ø     Chemical bonds are broken, atoms rearranged, and new bonds form in chemical reaction

Ø     Plants use sunlight to produce sugars such as C6H12O6 glucose; the chemical energy from the sun is stored in the chemical bonds of glucose

Ø      Organisms eat plants, break down the sugars, and release energy along with CO2 & H2O

Ø      Exergonic reactions involve a net release of energy; while endergonic reactions involve a net absorption of energy

Ø      Energy must be added to the reactants for most chemical reactions to occur; called activation energy

Ø      Enzymes are chemical substances in living things that act as catalysts & reduce the amount of activation energy needed

Ø      Organisms contain thousands of different enzymes

Ø      Most enzymes end with –ase (e.g. lipase is the enzyme that acts on lipids)

Reduction-Oxidation (Redox) reactions

Ø     Reactions in which e- are transferred between atoms is a redox or reduction-oxidation reaction (e.g. formation of table salt NaCl)

Ø     In oxidation reactions, a reactant loses 1 or more e- & becomes positively (+) charged (e.g. Sodium atom becomes a Na+ ion)

Ø     In a reduction reaction, a reactant gains 1 or more e- and becomes negatively (-) charged (e.g. Chlorine atom becomes a Cl- ion)

Ø     REDOX reactions always occur together; the electron(s) from the oxidation reaction are then accepted by another substance in the reduction reaction

Solutions

Ø     A large percentage of the mass of organisms is water & many of the chemical reactions of life occur in water

Ø     A solution  is a uniform mixture of one substance in anther

Ø     Solutions may be mixtures of solids, liquids, or gases

Ø     The solute is the substance uniformly dissolved in the solution & may be ions, molecules, or atoms

Ø     The solvent is the substance in which the solute is dissolved

Ø     Water is known as the universal solvent 

Ø     Dissolving one substance in another does not alter their chemical properties

Ø     The concentration of a solution is a measure of the amount of solute dissolved in a given volume of solvent

Ø     Increasing the amount of solute increases the solution’s concentration

Ø     Aqueous solutions are solutions in which water is the solvent; these are important in living things (e.g. blood, cytoplasm of cell…)

Acids and Bases

Ø     The degree of acidity or alkalinity (basic) is important in organisms

Ø     The force of attraction between molecules is so strong that the oxygen atom of one molecule can actually remove the hydrogen from other water molecules; called Dissociation

Ø      H20—–GOES TO—– H+  +  OH-

Ø     OH- called hydroxide ion; H+ called hydrogen ion

Ø     Free H+ ion can react with another water molecule to form H3O+  (hydronium ion)

Ø     Acidity or alkalinity is a measure of the relative amount of H+ and OH- ions dissolved in a solution

Ø     Neutral solutions have an equal number of H+ and OH- ions

Ø     Acids have more H3O+ ions than OH- ions; taste sour; and can be corrosive

Ø     Bases contain more OH- ions than H3O+ ions; taste bitter; & feel slippery  

 

Examples of Common Acids

  • citric acid (from certain fruits and veggies, notably citrus fruits)
  • ascorbic acid (vitamin C, as from certain fruits)
  • vinegar (5% acetic acid)
  • carbonic acid (for carbonation of soft drinks)
  • lactic acid (in buttermilk)
 Examples of Common Bases

  • detergents
  • soap
  • lye (NaOH)
  • household ammonia

PH Scale

Ø     Compares the relative concentration of H3O+ ions and OH- ions

Ø     Scale ranges from 0 to 14; 0-3 is very acidic; 7 is neutral; 11-14 is very basic or alkaline

 

Ø    Litmus paper, phenolphthalein, pH paper, & other indicators that change color can be used to measure pH

Buffers

Ø     Control of pH is important to organisms

Ø     Enzymes function only within a narrow pH range; usually neutral

Ø     Buffers neutral acids or bases in organisms to help control pH

Chemistry Study Guide Chemistry On-line

 

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Chapter 17 AP Objectives

 

Chapter 17    From Gene to Protein
Objectives
The Connection Between Genes and Proteins
1. Explain why dwarf peas have shorter stems than tall varieties.
2. Explain the reasoning that led Archibald Garrod to first suggest that genes dictate phenotypes through enzymes.
3. Describe Beadle and Tatum’s experiments with Neurospora and explain the contribution they made to our understanding of how genes control metabolism.
4. Distinguish between the “one geneÐone enzyme” hypothesis and the “one geneÐone polypeptide” hypothesis and explain why the original hypothesis was changed.
5. Explain how RNA differs from DNA.
6. Briefly explain how information flows from gene to protein.
7. Distinguish between transcription and translation.
8. Compare where transcription and translation occur in prokaryotes and in eukaryotes.
9. Define codon and explain the relationship between the linear sequence of codons on mRNA and the linear sequence of amino acids in a polypeptide.
10. Explain the early techniques used to identify what amino acids are specified by the triplets UUU, AAA, GGG, and CCC.
11. Explain why polypeptides begin with methionine when they are synthesized.
12. Explain what it means to say that the genetic code is redundant and unambiguous.
13. Explain the significance of the reading frame during translation.
14. Explain the evolutionary significance of a nearly universal genetic code.
The Synthesis and Processing of RNA
15. Explain how RNA polymerase recognizes where transcription should begin. Describe the promoter, the terminator, and the transcription unit.
16. Explain the general process of transcription, including the three major steps of initiation, elongation, and termination.
17. Explain how RNA is modified after transcription in eukaryotic cells.
18. Define and explain the role of ribozyme.
19. Describe the functional and evolutionary significance of introns.
The Synthesis of Protein
20. Describe the structure and functions of tRNA.
21. Explain the significance of wobble.
22. Explain how tRNA is joined to the appropriate amino acid.
23. Describe the structure and functions of ribosomes.
24. Describe the process of translation (including initiation, elongation, and termination) and explain which enzymes, protein factors, and energy sources are needed for each stage.
25. Describe the significance of polyribosomes.
26. Explain what determines the primary structure of a protein and describe how a polypeptide must be modified before it becomes fully functional.
27. Describe what determines whether a ribosome will be free in the cytosol or attached to the rough endoplasmic reticulum.
28. Describe two properties of RNA that allow it to perform so many different functions.
29. Compare protein synthesis in prokaryotes and in eukaryotes.
30. Define point mutations. Distinguish between base-pair substitutions and base-pair insertions. Give examples of each and note the significance of such changes.
31. Describe several examples of mutagens and explain how they cause mutations.
32. Describe the historical evolution of the concept of a gene.

 
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Protein Synthesis Quiz

Name: 

DNA & Protein Synthesis

 

 

True/False
Indicate whether the sentence or statement is true or false.
1.
When a tRNA anticodon binds to an mRNA codon, the amino acid detaches from the tRNA molecule and attaches to the end of a growing protein chain.
2.
Only ribosomal RNA plays a role in translation.
3.
During DNA replication, the molecule unzips and the exposed DNA nucleotides pair with other
specific nucleotides present in the nucleus
4.
Humans pass exact copies of their DNA to their offspring.
5.
Watson and Crick proposed a model of DNA
6.
Amino acids are linked together by hydrogen bonds.
7.
During transcription, the information on a DNA molecule is “rewritten” into an mRNA molecule.
8.
All codons encode amino acids.
 

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
9.
Purines and pyrimidines are
a.
bases found in amino acids.
b.
able to replace phosphate groups from defective DNA.
c.
names of specific types of DNA molecules.
d.
bases found in nucleotides.
10.
Chargaff’s rules, or the base-pairing rules, state that in DNA
a.
the amount of adenine equals the amount of thymine.
b.
the amount of guanine equals the amount of cytosine.
c.
the amount of guanine equals the amount of thymine.
d.
Both a and b
11.
ATTG : TAAC ::
a.
AAAT : TTTG
c.
GTCC : CAGG
b.
TCGG : AGAT
d.
CGAA : TGCG
12.
Which of the following types of RNA carries instructions for making proteins?
a.
mRNA
c.
tRNA
b.
rRNA
d.
All of the above
13.
Which of the following is not found in DNA?
a.
adenine
c.
uracil
b.
cytosine
d.
None of the above
14.
Suppose that you are given a polypeptide sequence containing the following sequence of amino acids: tyrosine, proline, aspartic acid, isoleucine, and cysteine. Use the portion of the genetic code given in the table below to determine the DNA sequence that codes for this polypeptide sequence.
mRNA
Amino acid
UAU, UAC
tyrosine
CCU, CCC, CCA, CCG
proline
GAU, GAC
aspartic acis
AUU, AUC, AUA
isoleucine
UGU, UGC
cysteine
a.
AUGGGUCUAUAUACG
c.
GCAAACTCGCGCGTA
b.
ATGGGTCTATATACG
d.
ATAGGGCTTTAAACA
15.
In order for protein synthesis to occur, mRNA must migrate to the
a.
ribosomes.
c.
RNA polymerase.
b.
lac operon.
d.
heterochromatin.
16.
After the primary structure of a protein has been completed
a.
the codons and anticodons unite.
b.
an enzyme attaches adjacent amino acids to each other to form a chain.
c.
the protein folds into the secondary and tertiary structures.
d.
the tRNA molecules remain attached until the protein is secreted from the cell.
17.
Which of the following is  not  part of a molecule of DNA?
a.
deoxyribose
c.
phosphate
b.
nitrogenous base
d.
ribose
18.
During replication in a molecule of DNA, one separation likely to occur is between
a.
cytosine and guanine
c.
ribose and adenine
b.
phosphate and deoxyribose
d.
uracil and thymine
19.
A gene may be described as
a.
a sequence of amino acids.
b.
special proteins found in chromosomes.
c.
a sequence of nucleotides that controls the production of a certain protein.
d.
a sequence of nucleotides coding for the production of starches and sugars.
20.
The synthesis of a new double strand of DNA begins when the two strand of the original DNA helix
a.
‘unzip’.
c.
attract nitrogenous bases.
b.
act as a template.
d.
destroy a genetic code.
21.
Genes(DNA) affect cell structure and function by directing the synthesis of
a.
nucleic acids
c.
nucleotides
b.
hereditary traits
d.
proteins
22.
Protein molecules are made up of
a.
fats
c.
lipids
b.
nucleotides
d.
amino acids
23.
During, DNA replication, DNA
a.
converts to RNA
c.
joins mRNA
b.
joins tRNA
d.
strands separate
24.
Which is not true about proteins?
a.
They control biochemical pathways within the cell.
b.
They direct the synthesis of lipids.
c.
They are composed of sugars.
d.
They take responsibility for cell movement.
25.
Molecules of DNA are composed of long chains of
a.
amino acids.
c.
monosaccharides.
b.
fatty acids.
d.
nucleotides.
26.
Watson and Crick were the first scientists to state that DNA
a.
contains phosphate groups
c.
has four nitrogen bases
b.
undergoes transcription
d.
has a double helix shape
27.
The two chains of a DNA molecule are connected by
a.
nitrogen bonds
c.
bases
b.
relatively weak chemical bonds
d.
nucleotides
28.
All nucleotide molecules contain the same kind of
a.
ribose sugar
c.
pyrimidine
b.
purine
d.
phosphate group
29.
After DNA replication, the two DNA molecules that are made
a.
are complementary.
c.
must replicate again.
b.
are identical.
d.
cannot replicate again.
30.
Sixty-four codons for 20 amino acids requires that
a.
some amino acids lack codons
b.
some amino acids have more than one codon
c.
all amino acids have two codons
d.
none of the above
31.
Which of the following combines with amino acids
a.
DNA
c.
tRNA
b.
mRNA
d.
B and C
32.
rRNA has a function in
a.
synthesizing DNA.
c.
forming ribosomes.
b.
synthesizing mRNA.
d.
transferring amino acids to ribosomes.
33.
The DNA code consists of sequences of nucleotides arranged in groups of
a.
variable number
c.
threes
b.
twos
d.
fours
34.
Unlike mRNA, the DNA molecule is
a.
double-stranded
c.
like a ladder
b.
single-stranded
d.
both A and C
35.
The number of bases in a row in a gene that codes a protein composed of 200 amino acids is
a.
200
c.
600
b.
400
d.
800
36.
A DNA molecule unzips during
a.
replication
c.
translation
b.
transcription
d.
both A and B
37.
A DNA chain has the following sequence of bases, TAG.  The corresponding messenger RNA
chain should have the sequence
a.
ATC
c.
ATG
b.
UTC
d.
AUC
38.
Unlike DNA, RNA
a.
contains deoxyribose.
c.
contains thymine.
b.
is double stranded.
d.
contains uracil.
39.
Which molecule contains deoxyribose
a.
DNA
c.
tRNA
b.
mRNA
d.
both B and C
40.
Each combination of three nitrogenous bases on messenger RNA forms a (an)
a.
anticodon.
c.
enzyme.
b.
codon.
d.
nuclei acid.
41.
In RNA, uracil is complementary to:
a.
guanine
c.
thymine
b.
adenine
d.
cytosine
42.
Once a molecule of transfer RNA has released its amino acid, the tRNA
a.
becomes attached to messenger RNA.
b.
becomes attached to ribosomal RNA.
c.
is destroyed as an individual molecule.
d.
moves away to pick up another amino acid.
43.
If the sequence of bases in a segment of a DNA strand were cytosine, guanine, adenine, thymine, adenine, then the sequence in a complimentary strand of newly-made mRNA would be
a.
cytosine, uracil, adenine, guanine, uracil
c.
uracil, adenine, cytosine, uracil, guanine
b.
guanine, cytosine, uracil, adenine, uracil
d.
cytosine, guanine, uracil, uracil, adenine
44.
Which sugar is present in RNA
a.
glucose
c.
ribose
b.
sucrose
d.
deoxyribose
45.
RNA differs from DNA, in that RNA
a.
is single-stranded.
c.
contains the nitrogen base uracil.
b.
contains a different sugar molecule.
d.
All of the above are correct.

 
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