BIOS1120 - Midterm Exam
In a nucleotides, the nitrogenous base is attached to the sugar's ____ carbon and the phosphate group is attached to the sugar's ____ carbon.
1' ... 5'
Drag the correct labels under the diagrams to identify the events of RNA processing.
1. A modified guanine nucleotide is added to the beginning of the RNA strand as a cap. 2. Segments of the RNA strand that do not actually code for the protein are removed. 3. Segments of the RNA that do code for the protein are reconnected. 4. Extra adenine nucleotides are added to the end of the RNA strand, forming a tail. 5. The completed messenger RNA (mRNA) leaves the nucleus.
Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have?
10
The innermost electron shell of an atom can hold up to ____ electrons.
2
In humans, gametes contain
22 autosomes and 1 sex chromosome
How many bases are in a codon?
3
Which of these is ATP?
3 phosphate, ribose, adenine
This atom can form up to ____ single covalent bond(s).
4 There are four electrons in the outermost electron shell.
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?
5
The direction of synthesis of an RNA transcript is ____.
5' --> 3'
Nucleic acids are assembled in the ____ direction.
5' to 3'
What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?
6
Which of these structures stores, modifies, and packages products?
A The Golgi apparatus modifies, stores, and packages products of the ER.
Which of the following events occurs during transcription?
A molecule of RNA is formed based on the sequence of nucleotides in DNA.
How are amino acids connected to form a polypeptide chain?
A peptide bond connects amino acids during a dehydration synthesis reaction.
Drage the labels onto the diagram to identify the structures of an animal cell.
A. Cytoskeleton B. Ribosomes C. Nucleus D. Smooth Endoplasmic Reticulum (ER) E. Cytosol F. Golgi Apparatus G. Rough Endoplasmic Reticulum (ER) H. Mitochondrion I. Plasma Membrane
Drag the pink labels onto the pink targets to identify the two main phases of the cell cycle. Then drag the blue labels onto the blue targets to identify the key stages that occur during those phases.
A. G1 phase B. S phase C. Interphase D. G2 phase E. Mitotic (M) phase F. Mitosis G. Cytokinesis
Drag the correct labels onto the diagram to identify the structures and molecules involved in translation.
A. mRNA B. small subunit of ribosomes C. large subunit of ribosome D. amino acid E. tRNA F. anticodon
Drag the pink labels onto the pink targets to identify key events in mitosis. Then drag the blue labels onto the blue targets to identify the stages of mitosis.
A. mitotic spindle forming B. sister chromatids centered C. chromosomes separating D. nuclear envelopes form E. interphase F. prophase G. metaphase H. anaphase I. telophase and cytokinesis
Drag the labels to their appropriate locations on the diagram. Facilitated Diffusion
A. plasma membrane B. side with higher concentration of molecules C. side with lower concentration of molecules D. facilitated diffusion causes a net movement of molecules down their concentration gradient E. transport protein
Drag the labels to their appropriate locations on the diagram. Diffusion
A. side with higher concentration of molecules B. plasma membrane C. side with lower concentration of molecules D. diffusion causes a net movement of molecules down their concentration gradient
Drag the labels to their appropriate locations on the diagram. Active Transport
A. side with lower concentration of square molecules B. transport protein C. energy input from the cell D. plasma membrane E. side with higher concentration of square molecules
What feature is common in all cells?
All cells have a plasma membrane.
____ is/are identical in structure to centrioles.
Basal bodies
In the accompanying image, a nucleotide is indicated by the letter ____.
Boxed off portion in the helixes.
Which of the given scenarios is most likely irreversible and an example of noncompetitive inhibition?
Boy A is playing a video game on a video game system. Boy B trips over the cords, pulling the game system off the shelf and breaking it.
A nitrogenous base is indicated by the letter ____.
C
Choose the letter that indicates the organelle that contains most of a cell's DNA.
C The nucleus contains most of a cell's DNA.
The structure that regulates the passage of material into and out of this bacterial cell is indicated by the letter ____.
C The plasma membrane is selectively permeable.
Which of these is(are) pyrimidines?
C, D, and E Pyrimidines are single-ring structures.
If the DNA sequence is G-C-C-T-A-T in one polynucleotide chain, then the sequence found in the other polynucleotide chain must be
C-G-G-A-T-A
____ is the most abundant organic compound on Earth.
Cellulose
How do competitive inhibitors stop a chemical reaction?
Competitive inhibitors bind in the active site of an enzyme.
What type of bond is joining the two hydrogen atoms?
Covalent A covalent bond is one in which electron pairs are shared.
Which of these provides the cell with structural support?
D Microfilaments are a component of the cytoskeleton.
The DNA-containing region of this bacterial cell is indicated by the letter ____.
D The nucleoid region contains DNA.
In the diagram below, the two blue strands represent ____.
DNA
Which of the following is so small, it is visible only with an electron microscope?
DNA
Which one of the following does not play a role in translation?
DNA
Which of these is a difference between a DNA and an RNA molecule?
DNA is double-stranded, whereas RNA is single-stranded.
The molecule that seals the gaps between the pieces of DNA in the lagging strand is
DNA ligase
Which statement about DNA replication is FALSE?
DNA ligase adds nucleotides to the lagging strand.
Which of the following build(s) new strands of DNA?
DNA polymerases
The first step of bacterial replication is ____.
DNA replication
A(n) ____ bond joins these two oxygen atoms.
Double covalent The oxygen atoms are sharing two pairs of electrons.
Which of these is the double membrane that encloses the nucleus?
E This is the nuclear envelope.
Most enzymes do not work at higher temperatures. Why is this?
Enzymes denature at higher temperatures.
Phospholipids have hydrophilic tail regions and hydrophobic head regions.
False
Which of these is a phospholipid?
First one - square then two legs with one bent Phospholipids are composed of a phosphate group, a glycerol, and fatty acids.
Which of these correctly illustrates the pairing of DNA and RNA nucleotides?
GTTACG CAAUGC
Why of the following reactions is an example of dehydration synthesis?
Glucose + galactose --> lactose
What is the purpose of mitochondria?
Mitochondria produce ATP using the energy in food.
Which of these figures correctly illustrates the nature of the bonding of H2O?
O(-) and H(+) Oxygen is more electronegative than hydrogen.
Drag each image to the phase of meiosis I it depicts.
Prophase I: jumbled in the middle Metaphase I: Forming a less jumbled portion in the middle Anaphase I: portions on both ends Telophase I & Cytokinesis: cytoplasms divide
Drag each image to the phase of meiosis II it depicts.
Prophase II: jumbled Metaphase II: line in middle Anaphase II: two separate lines on opposite ends Telophase II & Cytokinesis: chromosomes divide
Which of these is NOT a lipid?
RNA
In the diagram below, the gray unit represents ____.
RNA polymerase
How does RNA polymerase know where to start transcribing a gene?
RNA polymerase binds to the promoter of the gene.
What name is given to the process in which pre-mRNA is edited into mRNA?
RNA processing
Which of the following statements about ribosomes is correct?
Ribosomes are made from RNA and protein. They are used to synthesize proteins.
Drag the labels onto the flowchart to trace the movement of proteins through the endomembrane system and out of the cell.
Rough ER, Vesicle from ER, Golgi apparatus, Vesicle from Golgi, Plasma membrane
Drag the correct description under each cell structure to identify the role it plays in the cell. Nucleus Lysosome Mitochondrion Ribosome Smooth ER
Stores the genetic information of the cell. Breaks down macromolecules using digestive enzymes. Converts chemical fuel into packets of chemical energy that can power the cell. Works with mRNA to synthesize proteins. Site of lipid synthesis.
During DNA replication, which nucleotide will bind to an A nucleotide in the parental DNA?
T
What is the function of the telomere?
Telomeres are protective caps at the end of the chromosome.
Which statement about DNA replication is CORRECT?
The leading strand is built continuously, and the lagging strand is built in pieces.
What determines the types of chemical reactions that an atom participates in?
The number of electrons in the outermost electron shell.
Which of these relationships is true of an uncharged atom?
The number of protons is equal to the number of electrons.
Which of these illustrates the secondary structure of a protein?
The one strand that is curled in areas and straight in others. Alpha helices and beta pleated sheets are characteristic of a protein's secondary structure.
Phospholipids spontaneously form a bilayer in an aqueous solution. Why do the heads of phospholipids point out and the tails point toward one another?
The tails are repelled by the aqueous environment, and the heads will directly interact with the aqueous solution.
Which of these refers to atoms with the same atomic number but different atomic masses?
These atoms are isotopes.
What is the function of centrioles?
They produce microtubules for the chromosomes to migrate along as they move to opposite poles of the cell.
What is the function of the histones that are found in a chromosome?
They provide support for the DNA to form into a supercoiled structure.
Drag the correct labels onto the nucleotides in the RNA transcript. Not all labels will be used.
UCGA
What is the difference between saturated and unsaturated fats?
Unsaturated fats contain double and/or triple bonds.
The sex-determining chromosomes of a human male are the
X and Y chromosomes
What is NOT a feature of a prokaryotic cell?
a nuclear membrane
Glycogen is ____.
a polysaccharide found in animals
What is the definition of an endergonic reaction?
a reaction in which the products have more energy than the reactants
The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of
active transport
In a DNA molecule, base pairing occurs between
adenine and thymine
Enzymes are important because they
allow reactions to occur at body temperature
What is the monomer of a protein?
amino acid
Polypeptides are assembled from ____.
amino acids
Proteins are polymers of ____.
amino acids
A nucleolus is
an area in the nucleus of eukaryotic cells where ribosomes are synthesized and assembled.
An ionic bond involves ____.
an attraction between ions of opposite charge
The chromosomes are moving to opposite poles during
anaphase
Homologous chromosomes migrate to opposite poles during ____.
anaphase I
During ____ sister chromatids separate.
anaphase II
Atoms with the same number of protons but with different electrical charges ____.
are different ions
A function of cholesterol that does not harm health is its role ____.
as a component of animal cell membranes
Bacteria divide by
binary fission
Hydrolysis may be correctly described as the
breaking of a compound into its subunits by using water to break the bond between monomers.
Which of the following is NOT an organic molecule?
carbon monoxide
What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell?
cell wall
Growth factors stimulate
cells to divide
Which of these is a polysaccharide?
cellulose
Which of the following cell structures is NOT found in a bacterial cell?
central vacuole
The spindle fibers are produced by the
centrioles
The site on a chromosome where mircrotubules attach during cell division is the
centromere
The ____ is composed of DNA and protein.
chromatin
In prokaryotes, the DNA molecule is
circular
What primarily determines the shape of animal cells, which lack cell walls?
cytoskeleton
What is another name for a condensation reaction?
dehydration
In DNA, phosphate groups bond to
deoxyribose
Recognition proteins are most important for
distinguishing foreign cells from "self" cells
When a cell divides via asexual reproduction
each daughter cell receives a nearly perfect copy of the parent cell's genetic information
A substance with specific properties that cannot be broken down or converted into another substance is call a(n)
element
The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of
endocytosis
What is the correct label for "A"?
energy of activation
A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of
facilitated diffusion
Cytokinesis takes place during metaphase.
false
When 1 gram of each of these food sources is consumed, which yields the greatest amount of energy in calories?
fat
____ are surface appendages that allow a bacterium to stick to a surface.
fimbriae
The element carbon has atomic number 6. Carbon most likely
forms four covalent bonds.
Phospholipids are
found in cell membranes
Meiosis II typically produces ____ cells, each of which ____.
four ... haploid
Meiosis starts with a single diploid cell and produces
four haploid cells
The products of photosynthesis are
glucose and oxygen
What process occurs in Box A
glycolysis
Identify Structure A
glycoprotein Structure A is composed of both a carbohydrate and a protein.
Sexual reproduction allows for
greater genetic diversity in offspring, compared to asexual reproduction
During prophase I of meiosis,
homologous chromosomes stick together in pairs
What name is given to the bond between water molecules?
hydrogen
The brackets are indicating a(n) ____ bond.
hydrogen A hydrogen atom with a net positive charge is attracted to an oxygen atom with a net negative charge.
The secondary structure of a protein results from ____.
hydrogen bonds
What is the name of the process during which a bond between two monomers is broken?
hydrolysis
If digestion is ____, then synthesis is ____.
hydrolysis; dehydration synthesis
The phospholipids that make up the plasma membrane have ____ heads and ____ tails.
hydrophilic; hydrophobic
What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?
hyrolysis
Crossing over
increases variability in gametes
A cell preparing to undergo meiosis duplicates the chromosomes during
interphase
Cells spend most of their time in what phase?
interphase
Endocytosis moves materials ____ a cell via ____.
into ... membranous vesicles
In salt, what is the nature of the bond between sodium and chlorine?
ionic
Atoms or molecules that have gained or lost electrons are called
ions
An enzyme ____.
is an organic catalyst
As a result of mitosis, each of your body cells
is genetically identical to all other body cells
As a result of its involvement in a reaction, an enzyme ____.
is unchanged
The ____ portion of the cell membrane is responsible for the isolating function of the membrane, whereas the ____ portion regulates exchange and communication with the environment.
lipid; protein
Where is glycogen stored in vertebrate animals?
liver and muscles
RNA processing converts the RNA transcript into ____.
mRNA
Which of the following does not occur during RNA processing?
mRNA attaches to the small subunit of a ribosome.
Which of the following is a correct statement about mRNA?
mRNA moves from the nucleus to the cytoplasm following RNA processing.
Triglycerides are
made from glycerol and fatty acids.
glucose + glucose --> ____ by ____.
maltose + water ... dehydration synthesis
Homologous chromosomes
may exchange parts during meiosis pair up during meiosis are in pairs, one chromosome of each pair from the father and one from the mother have alleles for the same characteristics even though the gene expression may not be the same
In eukaryotes, gametes are produced by
meiosis
The chromosomes are aligned at the spindle equator during
metaphase
During ____ chromosomes align single file along the equator of a haploid cell.
metaphase II
Which of these are hollow rods that shape and support the cell?
microtubules
Which of these is a source of lactose?
milk
Which of these organelles carries out cellular respiration?
mitochondrion
A(n) ____ refers to two or more atoms held together by covalent bonds.
molecule
In active transport,
molecules move across the plasma membrane against their concentration gradient.
What is the monomer of a carbohydrate polymer?
monosaccharides
Flagellated cells can
move the cell through fluid
As shown in this figure, the top triglyceride (a) has ____, whereas the bottom triglyceride (b) has ____.
no double bonds and is saturated; double and/or triple bonds and is unsaturated
Which of these biological molecules contain genetic information?
nucleic acids
Where is a bacterial cell's DNA found?
nucleoid region
Ribosomal subunits are manufactured by the ____.
nucleolus
Adenosine triphosphate (ATP) is an example of a(n)
nucleotide
This is an image of a(n) ____.
nucleotide Nucleotides are composed of a pentose sugar, nitrogenous base, and a phosphate group.
Match the monomers with their polymers. Nucleic acid polymers are made up of ____ monomers. Carbohydrate polymers are made up of ____ monomers. Protein polymers are made up of ____ monomers.
nucleotide simple sugar amino acid
The atomic number of an atom is defined as the
number of protons in the atomic nucleus.
Which of these is rich in unsaturated fats?
olive oil
Membrane proteins are synthesized on ribosomes that are located
on the rough endoplasmic reticulum
What molecule is indicated by the letter D?
oxygen Oxygen is the final electron acceptor of cellular respiration.
What type of bond joins the monomers in a protein's primary structure?
peptide
Tertiary structure is NOT directly dependent on ____.
peptide bonds
Which of these organelles produces H2O2 as a by-product?
peroxisome
A white blood cell engulfing a bacterium is an example of ____.
phagocytosis
The letter A indicates a ____.
phosphate group
A nucleotide is made of a
phosphate, sugar, and nitrogenous base
Which type of lipid is most important in biological membranes?
phospholipid
Identify Structure D
phospholipid bilayer of membrane Phospholipids can be recognized by the presence of a head and two tails.
The ____ is a selective barrier, regulating the passage of material into and out of the cell.
plasma membrane
The ____ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell.
plasma membrane
During meiosis, segments of nonsister chromatids can trade places. This recombination of maternal and paternal genetic material is a key feature of meiosis. During what phase of meiosis does recombination occur?
prophase I
Synapsis occurs during ____.
prophase I
The correct order of events during meiosis is
prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis
During ____ a spindle forms in a haploid cell.
prophase II
What is the function of a bacterium's capsule?
protection
Ribosomes are the site of ____ synthesis.
protein
Enzymes are specialized ____ that catalyze chemical reactions within the body.
proteins
Most enzymes are
proteins
Ribosomes are a collection of
proteins and small RNAs that function in translation
Keratin and silk are examples of ____, whereas glucose and maltose are examples of ____.
proteins; carbohydrates
An atom's nucleus is composed of
protons and neutrons.
Enzymes work by ____.
reducing activation energy
Both prokaryotic and eukaryotic cells possess
ribosomes
In a bacterium, where are proteins synthesized?
ribosomes
What is the site of protein synthesis in the cell?
ribosomes
Which of the following is associated with rough ER?
ribosomes
____ are the sites of protein synthesis.
ribosomes
The site of translation is
ribosomes in the cell cytoplasm
Which of these manufactures cellular membranes by adding membrane proteins and phospholipids to its own membrane?
rough endoplasmic reticulum
This figure is an example of a(n) ____.
saturated fat The fatty acid tails lack double bonds.
DNA carries genetic information it its
sequence of bases
What type of bond joins the carbon atom to each of the hydrogen atoms?
single (nonpolar) covalent Each carbon-hydrogen bond involves a single pair of equally shared electrons.
Where is calcium stored?
smooth endoplasmic reticulum
What is the function of Structure E?
stabilization of the phospholipids Cholesterol helps to stabilize the structure of the plasma membrane.
All of the following are important functions of the cytoskeleton EXCEPT
storage of food molecules
What name is given to the reactants in an enzymatically catalyzed reaction?
substrate
The "backbone" of a nucleic acid molecule is made of
sugar and phosphate groups.
What forms the backbone of a DNA molecule?
sugar rings and phosphates
You can tell that this is an image of a DNA nucleotide and not an RNA nucleotide because you see a ____.
sugar with two, and not three, oxygen atoms
The terminal ends or "tips" of a chromosome are called
telomeres
The nuclear membrane re-forms during
telophase
At the end of ____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids.
telophase I
At the end of ____ and cytokinesis there are four haploid cells.
telophase II
Which step produces the most ATP?
the ETC
What is different concerning the DNA in bacterial cells as opposed to eukaryotic cells?
the amount of DNA present whether the DNA is housed in a nucleus or not whether the DNA is linear or circular
You can recognize the process of pinocytosis when ____.
the cell is engulfing extracellular fluid
What process occurs within Box B?
the citric acid cycle
In the diagram below, the green unit represents ____.
the promoter
In exergonic chemical reactions,
the reactants have more energy than do the products
Water crosses the plasma membrane
through facilitated diffusion or diffusion
Which of these nitrogenous bases is found in DNA but not in RNA?
thymine
In a DNA double helix an adenine of one strand always pairs with a(n) ____ of the complementary strand, and a guanine of one strand always pairs with a(n) ____ of the complementary strand.
thymine ... cytosine
What name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of pre-mRNA?
transcription
In eukaryotic cells the first step in protein synthesis is the ____.
transferring of information from DNA to messenger RNA
The process of converting the "message" of mRNA into a sequence of amino acids is called
translation
What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein?
translation
Which of the following groups includes carrier and channel proteins?
transport proteins
A duplicated chromosome consists of two sister chromatids.
true
Bacteria divide through a process called binary fission.
true
Energy is defined as the capacity to do work.
true
Most mutations are harmful or neutral, although in rare instances some can be beneficial. True or false?
true
Most prokaryotes reproduce via a form of asexual reproduction called prokaryotic fission. True or false?
true
Osmosis is the diffusion of water molecules across selectively permeable membranes. True or false?
true
The site of protein synthesis in the cytoplasm is the ribosome. True or false?
true
The two strands of DNA are held together by hydrogen bonds. True or false?
true
The uncoiled DNA in a eukaryotic cell is much longer than the cell itself. True or false?
true
Meiosis I produces ____ cells, each of which is ____.
two ... haploid
The Golgi apparatus packages material into ____ for transport or export.
vesicles
Large biological molecules are synthesized by removing
water
Which type of molecule is most abundant in a typical cell?
water
Where is DNA found in eukaryotic cells?
within the chromosomes inside the nucleus