Molecular/Cellular Flashcards
1
Q
Fifth and last stage of the prophase of meiosis, following diplotene, when the separation of homologous chromosomes is complete and crossing over has occurred.
A
Diakinesis
2
Q
What DNA segments are not translated?
A
Introns
3
Q
The function of the microtubule?
A
Platform for intracellular transport.
4
Q
What does the Calvin cycle not require?
A
Light
5
Q
A distinguishing feature separating retroviruses from normal viruses.
A
Retrovirus (such as HIV) genome consists of RNA
6
Q
Describe the use of DNA in a cell.
A
DNA is translated into proteins necessary for cell function.
7
Q
Describes a virus.
A
A small organism with a portion shell and DNA or RNA inside.
8
Q
Process of forming a blood clot:
A
Vascular spasm, the formation of a platelet plug, and coagulation (blood clotting).
9
Q
Are nucleotides present in all living cells?
A
Yes, nucleotides are basic DNA and RNA units, and as such are found in all living cells.
10
Q
What kind of transportation pumps molecules through the membrane with ATP.
A
Active transport
11
Q
The events through which bacteria can exchange DNA is known as:
A
Conjugation
12
Q
Describe the use of NAD+ in the Krebs cycle.
A
It is used to carry electrons.
13
Q
Hydrogen bonds can only exist between molecules that have:
A
A permanent dipole
14
Q
Name the vitamins that are co-factors and bind to an enzyme to activate or promote that enzyme’s activity.
A
Thiamine, Niacin, Riboflavin, Biotin, Vitamin A, K, C, B12
All water-soluble vitamins and two of the fat-soluble vitamins, A and K
15
Q
Which of the following is not a product of the electron transport chain?
- Water
- ADP
- ATP
- Hydrogen Ions
- NAD+
A
ADP
16
Q
The use of oxygen and a nutrient, such as glucose, to create an energy molecule is known as:
A
Aerobic respiration
17
Q
In the transcription and translation process, what is the job of the transport RNA (tRNA)?
A
Bringing amino acid units to the ribosome complex.
tRNA are attached to an amino acid unit, and are specific for a codon sequence of three base pairs.
18
Q
Watson-Crick model for DNA structure described DNA as a:
A
Double-stranded helix.
19
Q
Calvin cycle fixes carbon using enzyme:
A
RuBisCo
Turns CO2 into phosphoglycerate, and 3 carbon molecule.
20
Q
DNA polymerase can make errors as it makes copies of the genetic code. These errors can be proofread and fix by a combination of:
A
DNA polymerase (proofreads) and DNA ligase (repairs the mutations).
21
Q
Which enzyme is responsible for the translation of messenger RNA?
A
Ribosome
A protein that translates mRNA into a protein.
22
Q
How many ATP do these cycles produce?
- Kreb Cycle
- Glycolysis
- Electrons transport chain
A
- 0
- 2
- 32-34
23
Q
The cell cytoplasm can be described as:
A
A gel-like substance composed primarily of water which holds the cell’s organelles.
24
Q
A mutation in a strand of DNA that encodes for a protein will always result in the protein being misformed. Is this statement true or false, and why?
A
This statement is false. Each amino acid is coded for using a codon of 3 base pairs. However, each amino acid has multiple codons that can signal for that amino acid. For example, leucine can be CUG or CUA. If the G happens to mutate to an A, nothing happens to the protein as a whole.
25
Which of the following, if interrupted, would prevent crossing over from occurring in the human meiosis process?
1. Mitosis
2. Synapsis
3. Diakinesis
4. Telophase
Synapsis
| Synapsis is the process by which homologous chromosomes bind to each other, and is required for crossing over.
26
Genetic diversity in sexual reproduction is generated in meiosis, during:
Pachytene
| Genetic diversity is produced during crossing over or recombination of chromosomes.
27
In the Miller - Urey experiment, a soup of inorganic molecules, including ammonia, carbon dioxide, and water, were exposed to an electric current in an attempt to prove what?
That organic molecules such as amino acids could be made from inorganic molecules.
28
One of the best cancer drugs activates the kinase inhibitory protein, which interrupts the G1 phase of the cell cycle. This would have what effect?
The cancer cells would no longer grow or divide.
(The G1 phase of the cell cycle is also the growth cycle, and during this phase, the cell produces many proteins and organelles. Interruption of this phase would cause the cell to no longer grow or divide. However, the cell would likely not die immediately, although it would probably die after an extended duration. )
29
Glycogen is a branched glucose polymer stored in the:
Liver: Made and stored here.
| Glycogen is an energy molecule capable of being broken down into glucose.
30
In the cell, DNA is transcribed into RNA and then exported to the cytoplasm for translation into a protein. The basic components needed for translation of mRNA is:
Ribosome and tRNA
(In the process of translation, mRNA is read by a ribosome, which uses tRNA holding amino acids to construct the protein. Thus, the two components in addition to the mRNA that is needed for translation is a ribosome and tRNA. )
31
After fertilization, the human zygote will begin cell division. After 6 divisions, the zygote has how many cells?
64
| 2^6
32
Chromosomes are located in a nucleus in which of the following?
I. Viruses
II. Prokaryotes
III. Eukaryotes
Eukaryotes
33
Meiosis of a diploid cell results in how many haploid/diploid cell(s)?
4 Haploid cells
34
Neurotransmitters contained in vesicles enter the synapse through:
Exocytosis
(a form of active transport and bulk transport by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane.)
35
What type of bond joins oxygen to hydrogen within a single water molecule?
Polar covalent bond
36
The smallest unit of matter that has the properties of a particular element is a/n ____________.
Atom
37
A carbohydrate monomer is called a/n ______________.
Monosaccharide
38
What RNA sequences would bond to this DNA strand: AATAG?
UUAUC
| G-C, T-A, A-U
39
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What part of a cell membrane is fluid and can move from side to side, past other components of the membrane?
A. Lipids
B. Proteins
C. Nucleic Acids
D. A & B
E. All of the above
```
A & B
40
An enzyme-substrate complex is composed of which of the following?
I. enzyme
II. substrate
III. coenzyme
Both I and II
41
If a cell is hypotonic in relation to its environment. Will this cell gain or lose water?
Lose since hypotonic have lower osmotic pressure.
42
Which statement is FALSE about a cell’s cytoskeleton?
(A) microtubules are the largest of the 3 types of fibers
(B) intermediate filaments are stable and durable
(C) microfilaments support cellular projections like villi
(D) microtubules grow from the centrosome
(E) all of these are true statements correct
E
43
What do the light reactions produce that is used in the Calvin cycle?
ATP and NADPH
44
If chlorophyll looks green, which wavelengths of light does it reflect?
Green
| The 'color' of an object is the wavelengths of light that it reflects.
45
During what phase of mitosis does chromatin condense into chromosomes?
Prophase (first phase of mitosis)
46
What is meant by “redundancy” in gene expression?
Each amino acid can have more than one codon.
| Gene redundancy is the existence of multiple genes in the genome of an organism that perform the same function.
47
A virus can transfer genes from one bacterial cell to another through which process?
Transduction
| process by which foreign DNA is introduced into a cell by a virus or viral vector.
48
A covalent bond occurs when...
Two atoms share an electron
49
Which of the properties of water allow life to exist in a lake when the temperature is below freezing?
Solid is less dense than liquid.
50
Which of the following are hollow?
I. zygote
II. morula
III. blastula
III. blastula
51
Nitrogen-containing waste products are excreted as the result of the metabolism of which of the following?
Proteins
52
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Considering the role of mitochondria in cells, mitochondria would likely be most abundant in which of the following?
(A) mature red blood cells
(B) callous cells of the skin
(C) cells of the heart muscle
(D) epithelial cells of the cheek lining
(E) fat cells
```
(C) Cells of the heart muscle
53
Which of the following membranes is correctly matched to its function?
(A) allantois .. food absorption
(B) yolk sac .. embryonic bladder
(C) amnion .. gas exchange incorrect
(D) dura mater .. brain protection correct
(E) peritoneum .. heart protection
D. dura mater .. brain protection
| thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord.
54
A diet with insufficient iodine will most likely lead to which symptoms in an individual?
(B) decreased metabolic rate
55
All of the following statements about enzymes are true EXCEPT
(A) A single enzyme molecule can be used over and over again.
(B) Most enzymes are highly specific with regard to the reactions they catalyze.
(C) Some enzymes contain an essential nonprotein component.
(D) Enzymes can function only within living cells.
(E) Most enzymes are denatured by high temperatures.
(C) Some enzymes contain an essential nonprotein component.
56
Which of the following is critical in limiting the size to which an animal cell may grow?
The ratio of cell surface to cell volume.
57
The codon for a particular amino acid is 5'CAU3'. The DNA sequence that complements this codon is
3'GTA5'
| Parings: (G-C, T-A, A-U, 5-3)
58
Viral DNA would be most likely to contain genes that code for
viral-coat protein
59
Which of the following is the final electron acceptor in the mitochondrial electron transport system?
O2
| Without oxygen, the electrons will be backed up, eventually causing the electron transport chain to halt.
60
In a eukaryotic cell, glycolysis occurs in which of the following parts of the cell?
Cytosol
61
Which of the following elements is correctly linked to its role in a living organism?
(A) Calcium .. component of proteins
(B) Carbon .. component of lipids correct
(C) Magnesium .. neuron action potential incorrect
(D) Potassium .. component of ATP
(E) Zinc .. component of carbohydrates
(B) Carbon .. component of lipids
62
AMP is which type of molecule?
A Nucleotide
(AMP is one of RNA's components and also the organic component of the energy-carrying molecule ATP. In certain vital metabolic processes, AMP combines with inorganic phosphate to form ADP (adenosine diphosphate) and then ATP.)
63
Which of the following is generally true about bacterial viruses?
(A) They infect animal cells only.
(B) They have a protective capsid made of chitin.
(C) They inject their nucleic acids into the cells that they infect.
(D) They produce haploid gametes in meiosis.
(E) They carry out glycolysis but not the Krebs (citric acid) cycle.
(C) They inject their nucleic acids into the cells that they infect.
64
A typical photosynthetic eukaryotic cell contains which of the following?
I. Ribosomes
II. Chloroplasts
III. Mitochondria
ALL
65
Carbon dioxide is produced by which of the following?
I. A mesophyll cell in a flowering plant during the night
II. A muscle cell in a mammalian heart during contraction
III. A yeast cell growing under anaerobic conditions
ALL
66
Which of the following is a function of ATP?
It transport energy.
67
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Protein synthesis is the main function of which of the following structures?
(A) Nucleus
(B) Ribosome
(C) Chromosome
(D) Mitochondrion
(E) Vacuole
```
(B) Ribosome
68
The aerobic cellular respiration of glucose is different from the simple burning of glucose in that the aerobic respiration of glucose
occurs at a lower temperature
69
```
Which of the following types of plant cells is dead at functional maturity?
(A) Phloem companion cell
(B) Xylem vessel element
(C) Root endodermal cell
(D) Stem cortex cell
(E) Mesophyll cell
```
(B) Xylem vessel element
70
In a particular mammal, the egg has a haploid number of 8. How many chromosomes are in the somatic cells of that organism?
16
71
At which stage does a fibroblast cell divides at, synthesize at, and daughter cells separate at.
Stage 3, stage 2, Stage 4
72
The sequence of events in the synthesis of a protein molecule?
DNA, mRNA, tRNA, formation of polypeptide.
73
Malfunction sodium potassium pumps along a neuron's axon would likely result in:
A rapid decrease in the ability of the axon to conduct an action potential
74
In order to splice a foreign gene into a bacterial plasmid in the laboratory to create a recombinant plasmid, one would use:
Restriction enzymes
| DNA-cutting enzymes, each enzyme recognizes one or a few target sequences and cuts DNA at or near those sequences.
75
The process by which large fats are broken down into smaller droplets of fat for easier chemical digestion within the small intestine is called:
Emulsification
| Bile, secreted by the liver, is responsible for doing this within the lumen of the small intestine.
76
Ammonia and other nitrogen-containing organic matter are generally decomposed and converted into nitrogen gas by the reaction within the cells of:
Denitrifying bacteria
(takes organic nitrogen-containing matter (usually ammonia) and free up nitrogen from
it so that the gas can return to the atmosphere.)
77
The site of protein synthesis in eukaryotic cells:
Ribosome
78
Inner membrane made of convoluted cristae where ETC proteins can be found:
Mitochondria
79
The breakdown of a disaccharide releases energy which is stored as ATP. This is an example of a(n)
Exothermic reaction
80
What elements does protein contain?
Carbon, hydrogen, oxygen, and nitrogen.
81
A process by which a small piece of DNA can be copied multiple times so that there are many identical pieces of DNA to work with.
Polymerase chain reaction (PCR), allows pieces of DNA to be readily and rapidly copied, or amplified. The process does not need a living organism to do the DNA replication and can copy a DNA strand at an exponential rate.
82
The process by which DNA can be separated into various fragment lengths after digestion with a restriction enzyme.
Gel electrophoresis
83
In a cell that faces an oxygen debt, such as a heavily worked muscle cell, it is likely that
Fermentation will take place to manufacture more ATP.
As cells enter oxygen debt and no more oxygen exists to pick up electrons from the ETC, glucose processed into pyruvate by glycolysis gets shunted into a fermentation pathway that allows the cell to produce small extra amounts of ATP despite the fact that the ETC is working as hard as it can work. Carbon dioxide production will not increase because the Krebs cycle and mitochondria are not working any harder than they were before the oxygen debt occurred, and alternate fuel molecules still require the use of oxygen at the end of the ETC in order to be used for ATP production.
84
Inhibitory neurotransmitters such as GABA affect most neurons by
opening potassium or chloride channels in the axon membrane.
By opening up potassium or chloride ion channels in the axon membrane, inhibitory transmitters make it harder for a neuron to reach the threshold potential at which an action potential is created and a signal is sent. When potassium or chloride channels are opened in a neuron at rest, positive potassium ions can rush out from within the axon or negative chloride ions can rush into the axon. The result, either way, is that the inside of the axon becomes more negative and much harder to bring up toward threshold potential.
85
Heavy drinkers of alcohol typically have what is known as "fatty liver," because of an abundance of fats produced within liver cells. These fats are produced by which of the following organelles?
The smooth ER, which is used by the liver to detoxify the alcohol, also produces lipids for cell membrane building and other uses. As more and more smooth ER is built to counteract the heavy drinking, more and more fats build up in liver cells.
86
Macrophages and neutrophils constitute what type of response to pathogens?
Nonspecific
(Both are phagocytic cells that are part of the body"s nonspecific defenses, engulfing just about any pathogen or foreign particle that enters the human body)
87
The "RNA World" hypothesis postulates that
RNA was the first genetic material on Earth, and DNA developed from RNA
88
Electrons knocked out of chlorophyll molecules in photosystem II of the thylakoid membrane are replaced by the breakdown of
Water
(Electrons can be produced by breaking bonds in any molecule, but water is what is used in photosynthesis to resupply the chlorophyll.)
89
Bacterial production of lactase enzyme for lactose digestion is controlled by a gene unit known as the lac operon that controls gene expression by
The use of a repressor protein that can be bound to an operator region of DNA.
(RNA polymerase cannot transcribe the structural lactase genes unless the repressor is absent.)
90
Hormones that cannot cross the cell membrane but must signal DNA through the use of second messengers such as cAMP are generally members of which of the following classes of molecules?
Proteins
(Steroid hormones (lipids), can cross through the cell membrane to interact directly with DNA and proteins within a cell; however, protein hormones cannot and must act through receptors on the cell surface and second messenger molecules.)
91
The allosteric site of an enzyme
can bind a non-competitive inhibitor molecule.
92
A class of lipid molecules that is the building block of hormones such as estrogen and testosterone.
Steroids
93
The major portion of fatty acids is made of these non-polar, hydrophobic carbon-hydrogen skeletons.
Hydrocarbon chains, made of long groups of hydrogen and carbon atoms, are the major component of fatty acids, which are hydrophobic.
94
The process occurs when the inside of a nerve cell becomes positively charged for a brief interval as sodium ions rush inside.
Depolarization
| lasts a short time, and the cell returns to its naturally negative state.
95
Chromosomes in a human are numbered 1–22.
Chromosome pair #23 is made of the sex chromosomes, XX, or XY. All the others, 1–22, are the autosomes.
96
Pairs of chromosomes, one from the mother and one from the father, that have genes for the same traits in the same places.
Homologous chromosomes
97
Carbon dioxide and water are removed from the blood by the
Alveolus
(an air sac in the lungs, aids in the diffusion of carbon dioxide and water vapor out of the blood as well as permitting the diffusion of oxygen from the lungs into the bloodstream.)
