BIOL200 - Introduction to Cell Biology and Genetics
What is an anti-codon?
the part of tRNA that binds to the codon in the mRNA
If the ΔG of a reaction was -31.45 kJoules, you would know that:
the reaction is spontaneous.
Dehydration synthesis and hydrolysis reactions involve removing or adding ______ to macromolecule subunits.
-OH and -H
Black coffee has a pH of 5, therefore its H+ concentration is ___ times greater than a solution with a pH of 10.
100,000
Compare the relative hydrogen ion concentration of a solution of baking soda (pH9) to bleach (pH12) at 25 degrees Celsius. How many times greater/lower is the hydrogen ion concentration of the baking soda solution compared to the bleach?
1000 times higher
Atomic mass of Carbon (P = 6; N = 6)
12
Atomic number of Aluminum (P = 13, N = 14)
13
You are studying meiosis in an organism where 2n= 28. How many chromosomes will be present in each cell after meiosis I is complete but before meiosis II begins?
14
You are studying meiosis in an organism where 2n=28. How many chromosomes will each nucleus have after meiosis II is complete?
14
If a parent cell has 18 chromosomes prior to mitosis, how many chromosomes will the daughter cells have?
18
You are studying meosis in an organism where 2n=36. How many chromosomes will be present in each cell after meiosis I is complete but before meiosis II begins?
18
You are studying meosis in an organism where 2n=36. How many chromosomes will be present in each cell after meiosis II is complete?
18
Arrange the following proteins in the proper order in which they participate in DNA replication. 1 = Primase 2 = Helicase 3 = Single-strand binding proteins 4 = DNA polymerase I
2, 3, 1, 4
If a DNA molecule contains 30% thymine, how much guanine will it contain?
20%
Comparing the pairs of elements listed below, choose the pair in which both atoms have nuclei with the same number of neutrons.
2311Na and 2412Mg
Atomic Mass of Aluminum (P = 13, N = 14)
27
In a single sodium-potassium pump cycle, ATP is used with the result that
3 sodium ions leave and 2 potassium ions enter.
In Mendel's experiments on seed color in pea plants, when a dominant yellow seed-bearing plant was crossed with a recessive green seed-bearing plant, what was the approximate phenotypic ratio among the F2 generation?
3 yellow: 1 green
The synthesis of a growing strand of DNA is carried out by adding nucleotides to the ___ end of an existing strand.
3'
The DNA sequence capable of pairing with 5' CGATTAGT 3' is:
3' GCTAATCA 5'
If a short sequence of DNA is 5' AATTGCCGT 3', its complement is
3' TTAACGGCA 5'
Atomic number of Zinc (P = 30, N = 35)
30
If 14% of the nucleotides from a DNA molecule contain the base T, what percent will contain the base G?
36%
Valance electrons in carbon (P = 6, N = 6)
4
An atom has 20 electrons and 20 neutrons. What is the mass of this atom?
40
If a parent cell has 48 chromosomes, how many chromosomes will each daughter cell have after mitosis and cytokinesis occurs?
48 chromosomes
A chemist adds a chemical to pure water and there is a 100-fold increase in the concentration of hydrogen ions. What is the best approximation of the new pH value?
5
If the sequence of bases in the template strand of a DNA molecule is 3' ATCGCTCC 5', what is the sequence of bases in the RNA that is transcribed from this molecule?
5' UAGCGAGG 3'
Which of these options only contain nitrogenous bases that are purines?
Adenine and Guanine
Which of the following is true of all living organisms?
All acquire and use energy.
Barr bodies — Are inactivated X chromosomes a. Are inactivated X chromosomes Are an example of dosage compensation Can lead to genetic mosaics Influence calico cat coloration All of the above
All of the above
Which of the following statements are true about cellulose? Serves as a structural material Is made of β-glucose molecules linked in chains Cannot be digested by most organisms All of the above
All of the above
Which of the following is NOT one of the steps in intiation of translation?
Formation of a polypeptide bond.
At what checkpoint(s) does the cell arrest in response to DNA damage?
G1/S and G2/M
Name the cell cycle stage. (image 3.33)
G2
This stage of the cell cycle is characterized by growth and it contains a checkpoint to verify that all of the DNA has been replicated prior to mitosis.
G2
During which phases of the cell cycle do the chromosomes exist in a replicated state?
G2 and early M
What stage of cellular respiration can occur in human cells with or without oxygen present?
Glycolysis
When oxygen is unavailable during heavy exercise what process do muscle cells use for energy generation?
Glycolysis coupled with lactate fermentation
Match the organelle with its function. Packages proteins for export from cell; forms secretory vesicle
Golgi apparatus
The organelle that can collect, package, modify, and transport molecules is called the:
Golgi apparatus
The chemical source of molecular oxygen O2 in photosynthesis is
H20
Height is a trait that shows continuous variation in humans. In pea plants, on the other hand, the tall allele is dominant over the short allele and there are no intermediate heights. What is the best explanation for this difference?
Height is a polygenic trait in humans.
The pH of your small intestines is around 7.5 and the pH of your large intestine can be 5.5. As substances travel from the small intestines to the large intestine, what would happen to the H+ ion concentration?
It increases by 100-fold.
What happens to the oxygen that is used in cellular respiration?
It is reduced to form water
What is the importance of fermentation to cellular respiration?
It oxidizes NADH to NAD+ in the absence of oxygen
You recently discovered a new element, and find that this particular element has one electron in its outer energy level. What would you expect will happen to an atom of this element if placed in water?
It will lose an electron forming a positive ion.
If a cell were placed in a solution with a high potassium concentration and no sodium, what would happen to the sodium-potassium pump's activity?
It would continue using ATP to pump sodium out of the cell and potassium into the cell.
If you were able to increase the kinetic energy of the molecules inside your body, how would this affect your body temperature?
It would increase
Carbon dioxide and water can combine to form glucose, water and oxygen. What is required for that process to occur?
Light energy from the sun
Under which of the following conditions would lac operon expression in E. coli be maximal?
Low levels of glucose, high levels of lactose
Match the organelle with its function Digest worn-out organelles and cell debris; digest material taken up by endocytosis
Lysosomes
Match the appropriate functional groups to the physical and chemical properties described. Nonpolar, hydrophobic, found in hydrocarbon chains.
Methyl Group
The three principle fibers of the cytoskeleton are:
Microtubules, microfilaments, and intermediate filaments
Match the organelle with its function "Power plants" of the cell; sites of oxidative metabolism
Mitochondria
What does it mean when we say the genetic code is redundant?
More than one codon can specify the addition of the same amino acid.
An atom has 10 electrons and 10 neutrons. What is the mass of this atom?
20
Why does replication proceed in opposite directions on the leading and lagging strands?
DNA polymerase III can only add nucleotides to the 3' end of a strand
If heated, a protein may change its shape or even unfold completely. This is called:
Denaturation
The electronegativity of nitrogen (N) is 3.0, while the electronegativity of hydrogen (H) is 2.1. Knowing this, consider how the electrons will be shared in ammonia (NH3). What do you predict about the polarity of ammonia?
Each H atom has a partial positive charge
A protein that has many hydrophobic R-groups pointing to the outside of the protein would be found where?
Embedded within a membrane.
A chemical imbalance in the blood can cause the heart to stop pumping blood, which will have a detrimental effect on other organs. This observation can be attributed to:
Emergent properties
Which characteristic of life does this best represent? The body temperature of a dog is more stable than the temperature of its environment.
Homeostasis
What is the name of the functional group designated -OH?
Hydroxyl
When the substrate is bound to the enzyme, the shape of the enzyme may change slightly, leading to:
an induced fit
During what stages of the cell cycle are sister chromatids bound together by cohesin?
S, G2, prophase, metaphase
Phospholipids are made up of:
a phosphate, two fatty acids and a glycerol.
Cholesterol is
a precursor of steroid hormones
Experiments are carried out to test a hypothesis by changing one variable at a time and including an unchanged variable termed a(n) _____
control
Experiments are carried out to test a hypothesis by changing one variable at a time and including an unchanged variable termed a(n) _____.
control
The light-independent reactions of photosynthesis are those that
convert CO2 into reduced molecules (sugars).
The light reactions of photosynthesis
convert light energy into chemical energy.
When proteins are denatured, which type of bond is NOT disturbed?
covalent bonds
DNA primase
creates a short RNA primer that is complementary to a DNA template.
Cdks bind with ___________, enabling the Cdks to regulate cell cycle events.
cyclins
Name this cell cycle stage. (image 3.31)
cytokinesis
The semifluid matrix that surrounds organelles in a cell is called the:
cytoplasm
Which of the following are similarities between the structure and function of mitochondria and chloroplasts? a. They both create internal proton gradients by electron transport. b. They both generate CO2 by oxidation reactions. c. They both have a double membrane system. d. Both a and c are correct.
d. Both a and c are correct.
In eukaryotes, mitochondria are the organelles primarily involved in:
energy release/capture.
Through control of gene expression, a bacterial cell responds to changing __________ conditions.
environmental
Sometimes, one gene will interfere with the expression of a second gene in an interaction called
epistasis
The type of movement of molecules that is specific and passive, and which becomes saturated if all of the protein carriers are in use is
facilitated diffusion.
All biological macromolecules are polymers made from repeating individual subunits called monomers.
false
The two nucleic acid strands of a DNA molecule are held together by polar covalent bonds between the complementary bases.
false
Fire can grow and "reproduce". It takes in and uses energy. It responds to the environment. Why isn't fire considered to be alive? Give AT LEAST two reasons.
fire cannot maintain homeostasis and it does not have cellular organization. Fire is not composed of cells; it does not maintain homeostasis; it does not have genetic material; it does not evolve.
In photosynthesis, carbon fixation occurs:
in the Calvin cycle
All the offspring from a white hen and a black rooster are grey. The simplest explanation for this pattern of inheritance is...
incomplete dominance.
Both walnut and Gingko trees lose their leaves in the fall when day length starts decreasing. Based on these observations one may conclude that many tree species will lose their leaves in the fall in response to decreasing day length. This statement is an example of:
inductive reasoning
The energy released in the mitochondrial electron transport chain is used to transport protons into the
intermembrane space of the mitochondria.
The lac operon regulatory system is important to bacteria primarily because lactose
is only rarely available; producing enzymes all the time is costly.
Could the amino acid substitution shown above have an affect on the structure or function of the whole protein? Why or why not? Explain your reasoning. (refer to paper)
it could have an effect on the structure and function of the protein because any change in an amino acid in a protein can change what the protein looks like and does.
Is this molecule a monosaccharide? Explain your reasoning. (refer to paper)
it's not a monosaccharide because the C:H:O ratio should be 1:2:1 and you don't have enough O. You have 10 H meaning you should have 5 C and 5 O but you only have 4 O.
Full induction of the lac operon occurs when:
lactose levels are high and glucose levels are low
During replication, this enzyme links the backbone of Okazaki fragments.
ligase
The biological macromolecule that is least soluble in water is a(n):
lipid
Match each example or description with the corresponding level of protein structure.
look at picture of chap 3 hmwk 3 question 3
A distinctive feature of eukaryotes is the organization of tightly packaged chromosomal DNA with proteins into a membrane-bound structure called a:
nucleus
Carbon is an important element for biology, because
of the variety of carbon skeletons and functional groups that can be built on them.
When preparing your experiment for a laboratory exercise, how many substances or conditions should you test at a time?
one
Each newly formed DNA molecule consists of
one parental strand and one daughter strand.
Semi-conservative replication involves a template. What is the template?
one strand of the DNA molecule
Your brain is an example of a(n) ____
organ
Molecules may be assembled into a microscopic structure called a(n) _____ which carries out specific functions within a cell.
organelle
If a cell is in an isotonic environment, then
osmosis still occurs, but there is no net gain or loss of cell volume.
The loss of an electron by a molecule is called _______________.
oxidation
Denaturation disrupts the secondary and tertiary structure of proteins. However, denaturation is not strong enough to disrupt what interaction that is relevant to protein structure?
peptide bonds
What type of bonds link individual amino acids together?
peptide bonds
The observable expression of the genes present in an organism is called its
phenotype
Nucleotides are linked together by what kind of bond?
phosphodiester bond
The types of bonds found in nucleic acids are:
phosphodiester bonds
Light consists of units of energy called
photons
Which of the following is the proper hierarchy starting with the simplest?
proton < nitrogen < amino acid < polypeptide < protein
During replication, this protein stabilizes the single stranded template.
single-stranded binding protein
These structures are held together by cohesion:
sister chromatids
Nucleotides are added onto what part of a growing nucleic acid polymer?
the -OH on the 3-prime carbon
In DNA, a purine must always pair with a pyrimidine and vice versa in order to ensure that
the distance between the two phosphodiester backbones remains constant
Which of the following is mostly likely to serve as an allosteric inhibitor providing feedback inhibition to a biochemical pathway?
the end (final) product of the pathway.
In order to reuse an enzyme after the conclusion of an enzyme catalyzed reaction, what must occur?
the enzyme has to separate itself from the product
Mitosis produces _______________.
two identical daughter cells.
Olive oil is a liquid at room temperature and is therefore expected to have a high proportion of _____________ fatty acids.
unsaturated
Most atmospheric oxygen comes from photosynthesis. From which of the following molecules is the oxygen derived?
water
When forming a semi-solid gel such as gelatin, which molecules does the process of protein coagulation entrap?
water molecules
Prokaryotic cell movement is attributed to:
flagella
Proteins are created with:
peptide bonds
Identify the parts of a plant cell.
(image 2.9)
An atom has an atomic number of 10 and an atomic mass of 19. How many protons and neutrons does it have?
10 protons and 9 neutrons
An exergonic reaction has the following properties:
-ΔG and the reaction is spontaneous
Atomic number of hydrogen (P = 1, N = 1)
1
Urine has a pH of 6, therefore its H+ concentration is ___ times greater than a solution with a pH of 9.
1,000
Based on hierarchical organization, place the living systems in order from smallest to largest. Blue wildebeests, Black wildebeests, crocodiles, acacia trees Blue wildebeest (Connochaetes taurinus) Blue wildebeests Blue wildebeests and Black wildebeests Maasai Mara
1. Blue Wildebeest (Connochaetes taurinus) 2. Blue Wildebeests 3. Blue Wildebeests and Black Wildebeests 4. Blue wildebeests, Black wildebeests, crocodiles, acacia trees 5. Maasai Mara
Indicate whether each of the following statements about polysaccharides is True or False. 1. Polysaccharides are long polymers made of many nucleotides that have been joined through dehydration synthesis. 2. Cellulose is the main storage polysaccharide in plants while glycogen is an important storage polysaccharide in many animals. 3. Both starch and glycogen are composed of α-glucose subunits. 4. Starch is composed of amylose and amylopectin, which are unbranched and branched chains of α-glucose subunits, respectively. 5. Like amylopectin, glycogen is insoluble in water, but it has a longer average chain length and fewer branches. 6. Although some polysaccharides are used to store energy, others serve as structural material for cells. 7. The principal structural polysaccharide in plants is starch. 8. Cellulose is composed of a long, branched chain of β-glucose subunits.= 9. The starch-hydrolyzing enzymes produced by most organisms cannot break the bond between two α -glucose subunits because they only recognize β linkages. 10. Chitin is a structural polysaccharide found in the exoskeleton of arthropods and the cell wall of many fungi.
1. False 2. False 3. True 4. True 5. False 6. True 7. False 8. False 9. False 10. True
Carbohydrates are used in cells for structural purposes and as an energy source. What is the main type of carbohydrate contained in each of the following? 1. Potato as food 2. Fruit as food 3. Stored human energy 4. Human blood sugar.
1. starch 2. fructose 3. glycogen 4. glucose
Household ammonia has a pH of 11, therefore its H+ concentration is ___ times less than a solution with a pH of 7.
10,000
Beer has a pH of 3, therefore its H+ concentration is ___ times greater than a solution with a pH of 5.
100
Indicate whether each of the following statements about protein structure is true or false. 1. If a protein's environment is altered, the protein may change its shape or even unfold completely, a process called dissociation. 2. Proteins can denature when the pH, temperature, or ionic concentration of the surrounding solution changes. 3. Denatured proteins are usually biologically active. 4. When normal environmental conditions are reestablished after protein denaturation, almost all proteins can spontaneously refold back into their natural shape. 5. If the 3-D structure of a protein depends only on its primary structure and the surrounding environmental conditions, then when the protein is denatured and subsequently returned to its native conditions it will spontaneously refold back into its native structure. 6. Proteins have a narrow range of conditions in which they fold properly; outside that range, proteins tend to renature. 7. Some proteins require other proteins called chaperones in order to correctly fold into their normal 3-D shape. 8. Cells use chaperones both to accomplish the original folding of some proteins and to restore the structure of incorrectly folded ones. 9. Some diseases may occur because a protein with the correct amino acid sequence fails to correctly fold into its final functional form. 10. During a process called dissociation, the polypeptides of a protein with quaternary structure separate and unfold, losing their individual tertiary structure. 11. The final 3-D shape of a protein is determined entirely by its primary structure.
1. False 2. True 3. False 4. False 5. True 6. False 7. True 8. True 9. True 10. False 11. False
Indicate whether each of the following statements about protein structure is true or false. 1. A distinctive and recurrent sequence of structural elements within a protein, such as helix-turn-helix, is called a domain. 2. Many proteins are composed of several different regions that are specialized to carry out specific functions. 3. Specific functional regions within a protein are called motifs. 4. As a polypeptide chain folds, each domain takes its proper shape more or less independently of the others. 5. If we replace one domain of a protein with a domain from a different protein using molecular biology techniques, then the entire protein will become inactive.
1. False 2. True 3. False 4. True 5. False
A hypothesis is a general principle or explanation that is derived from observations. Suppose you make the following observations: a. You look at 10 human liver cells and observe that each one has a nucleus. b. You look at 10 onion cells and observe that each one has a nucleus. c. You look at 10 nerve cells from a mouse and observe that each one has a nucleus. For each statement below, mark "True" if it would be a valid hypothesis, based on these three observations alone, and mark "False" if it would not be a valid hypothesis. 1. The onion cells I looked at have a nucleus. 2. All onion cells have a nucleus. 3. All cells have a nucleus. 4. Some cells have a nucleus. 5. Only onion cells have a nucleus. 6. If I look at 10 skin cells from my hand, each one will have a nucleus.
1. False 2. True 3. True 4. False 5. False 6. False
Based on hierarchical organization - put these structures in order from smallest to largest. Myosin protein Muscular system Biceps brachii muscle Skeletal muscle tissue Skeletal muscle cell
1. Myosin protein 2. Skeletal Muscle Cell 3. Skeletal Muscle Tissue 4. Biceps Brachii muscle 5. Muscular System
For each statement below, indicate whether it is true or false. 1. All living organisms are composed of one or more cells. 2. Different cell types develop in a multicellular organism because each cell has its own unique set of genes. 3. Underlying similarities in biochemistry and genetics support the idea that all life evolved from a single ancestor. 4. Molecules in different organisms that perform the same function are likely to have a similar structure. 5. Evolutionary conservation explains the diversity of life. 6. Information stored in inorganic molecules is used to direct the synthesis of cellular components. 7. Cells process information stored in their DNA as well as information they receive from the environment. 8. Organisms are closed systems that require an input of energy in order to maintain their high level of complexity and organization. 9. Homeostasis is possible because elaborate signaling networks coordinate the activities of different cells within an organism. 10. The unity of living systems arises through evolutionary change.
1. True 2. False 3. True 4. True 5. False 6. False 7. True 8. False 9. True 10. False
Based on the hierarchical organization, order these terms from smallest to largest. carbon water mitochondria skin cell DNA
1. carbon 2. water 3. DNA 4. mitochondria 5. skin cell
Electrons in Neon (P = 10, N = 10)
10
(week 3 hmwk question 1) Fructose has ___ carbon atoms.
6
In order to generate one molecule of glucose, how many times does the Calvin cycle have to turn?
6
Valance electrons in chlorine (P = 17, N = 18)
7
If a somatic cell of a diploid organism has 8 chromosomes, how many chromosomes will each daughter cell have after two (2) mitotic cell divisions?
8
Just before prophase begins, how many chromatids would a diploid human body cell contain?
92
A particular reaction has a negative delta G. However, this reaction takes many years to proceed in the absence of enzyme. Why is this the case?
A certain amount of activation energy is required for the reaction to proceed
What should your hypothesis represent?
A possible explanation for a problem or observation
If one parent has type B blood and the other has type AB, what type might the child have?
A, B, AB only
A new drug, tested to treat a large range of respiratory issues, causes severe side effects in humans. The inner membranes and cristae in the mitochondria of people taking this drug become leaky and less able to maintain ion gradients. Because of this condition these individuals cannot produce adequate amounts of _______.
ATP
The chief energy currency all cells use is a molecule called
ATP
What products of light reactions of photosynthesis are used in the Calvin cycle?
ATP and NADPH
The first codon in a mRNA to specify an amino acid is always
AUG
Acyclovir is an antiviral chemical that resembles a nucleotide but lacks a 3' OH group and cannot form phosphodiester bonds. Why is Acyclovir useful in treating some viral infections?
Acyclovir halts viral DNA replication.
An error in meiosis that results in an abnormal number of chromosomes in the final haploid cell can result from the failure of chromosomes to move to opposite poles during meiosis I. can result from the failure of chromosomes to move to opposite poles during meiosis II. is a condition called aneuploidy. can result from nondisjunction. All of the above are true.
All of the above are true.
Based on hierarchical levels of biological organization, which of these choices represents the broadest level? 3 toed sloths Endocrine system Jaguars, giant anteaters, macaws, capybaras School of piranhas Amazon Basin
Amazon Basin
Match the appropriate functional groups to the physical and chemical properties described. Polar, soluble, can act as a weak base and can accept a proton.
Amino Group
Metabolic reactions fall under two general categories: anabolic and catabolic. What type of chemical reactions are these two classes of metabolic reactions?
Anabolic reactions are endergonic reactions, whereas catabolic reactions are exergonic.
Which statement about mitosis and cytokinesis is TRUE?
At the end of cytokinesis there are two daughter cells with a normal complement of diploid genetic material.
Consider the following electronegativity values: Boron (B) = 1.8 Carbon (C) = 2.5 Chlorine (Cl) = 3.2 Selenium (Se) = 2.6 Which of the following bonds is the most polar?
B-Cl
Suppose a new species of bacterium is discovered. It contains a form of DNA pol III that can add new nucleotides to either the 5' end or the 3' end of an existing strand. All other properties of the enzyme remain unchanged. How would DNA replication in these bacteria differ from normal replication?
Both new strands could be synthesized continuously like the leading strand
Which of the following would cause an increase in entropy?
Breaking down glucose to carbon dioxide and water during cellular respiration
The formula for glucose is C6H12O6. What is the formula for a polymer made by linking 10 glucose molecules together by dehydration synthesis?
C60 H102 O51
Water interacts with polar substances like -OH groups but not with non-polar substances like methyl (−CH3) or ethyl groups (−CH2). Using this information, select the molecules that will easily dissolve in water based on polarity not on size. Check all that apply. CH4 CH3OH CH3 CH3 CH3 CH2 CH2 OH CH3 CH2 CH2 CH2 CH2 CH3
CH3OH CH3 CH2 CH2 OH
A single atom of carbon:
Can form up to 4 single covalent bonds
What facts would you select to show the major significance of the element carbon in the human body? Check all that apply. Carbon's ionized form makes body fluids acidic. Carbon is the main constituent of water. Carbon has four valance electrons. Carbon forms the backbone of all organic molecules. Carbon can form bonds with four different atoms. Carbon-containing molecules can form rings, branches, or coils.
Carbon has four valance electrons. Carbon forms the backbone of all organic molecules. Carbon can form bonds with four different atoms. Carbon-containing molecules can form rings, branches, or coils.
Match the appropriate functional groups to the physical and chemical properties described. Polar, soluble, protons can dissociate from this group and it has acidic properties.
Carboxyl Group
How does peer review influence the development of scientific theories?
Careful evaluation of research results by other scientists ensures that only solid and legitimate research results are published, and helps prevent faulty research or false claims from being viewed as scientific fact.
Bacterial and eukaryotic cells primarily control gene expression at the level of transcription. If instead cells exerted control of gene expression primarily at the post-translational level, what would be different?
Cells would expend significantly more energy.
Match the organelle with its function Sites of photosynthesis
Chloroplasts
Does ADP contain the capacity to provide energy for the cell?
Cleaving the bond between the terminal phosphate and the phosphate attached to the ribose sugar can provide energy for the cell.
Genetic recombination occurs as a result of —
Crossing over
Mitochondria and chloroplasts are the other organelles besides the nucleus that contain:
DNA
What common life characteristic would cells from a daisy, an apple and a dog all have?
DNA
What common life characteristic would cells from a daisy, bacteria, and a dog all have?
DNA
Match the enzyme to the appropriate function. This enzyme relieves the torque caused by rapid unwinding of template DNA.
DNA Gyrase
Match the enzyme to the appropriate function. During replication this enzyme untwists the DNA helix.
DNA Helicase
Match the enzyme to the appropriate function. This enzyme links Okazaki fragments.
DNA Ligase
Match the enzyme to the appropriate function. This enzyme removes the RNA primers and replaces them with DNA.
DNA Polymerase I
Match the enzyme to the appropriate function. During replication this enzyme synthesizes the new strand of DNA.
DNA Polymerase III
This enzyme relieves the supercoils caused by unwinding the template DNA.
DNA gyrase
Which of the following is NOT one of the steps in initiation of translation?
Formation of a polypeptide bond.
Which statement represents the biological characteristics that kittens, oak trees, swans, earth worms, elephants and crickets have in common?
DNA nucleotides form the basis of all inherited life, with cells that are formed from other cells.
During replication, this enzyme removes RNA primers and replaces them with DNA.
DNA polymerase I
During DNA replication, this enzyme synthesizes a new complementary strand of DNA.
DNA polymerase III
Match the organelle with its function. Intracellular compartment forms transport vesicles; participates in lipid synthesis and synthesis of membrane or secreted proteins
Endoplasmic Reticulum
Which characteristic of life does this best represent? In order to carry out essential life functions such as growth, development, and movement, a duck must eat.
Energy Utilization
Which statement about thermodynamics is NOT true?
Entropy tends always to decrease.
Which statement about the genetic code is false?
Every codon codes for one amino acid.
Which characteristic of life does this best represent? In 1980, scientists determined that 2% of the honey bees in Texas had a gene that makes them more aggressive. By 2005, the frequency of this gene in the Texas honeybee population had increased to 15%.
Evolution
All cells have DNA, but only eukaryotic cells have DNA and RNA
False
All cells have plasma membranes, DNA and mitochondria.
False
All genes (nuclei, mitochondrial, chloroplasts) are inherited from both parents.
False
All prokaryotes are unicellular and all eukaryotes are multi-cellular.
False
Catabolic reactions expend energy to form or transform chemical bonds.
False
Klinefelter Syndrome and Turner Syndrome are the result of abnormal numbers of autosomes.
False
The nucleolus functions mainly in the synthesis of DNA.
False
True or False: Connection of an amino acid to a tRNA is a spontaneous reaction.
False
True or False: RNA polymerase requires a primer in order to initiate transcription.
False
True or False: RNA polymerase synthesizes a new strand of RNA in the 3' to 5' direction.
False
True or False: Living organisms contain unique chemical elements which are not found in non-living systems.
False
True or False: Organisms produced as a result of mitosis exhibit a great deal of genetic variation.
False
True or False: Scientists have successfully sequenced the entire genome of humans but have not yet sequenced the entire genome of any other species.
False
Two organelles that are believed to have once been free-living bacterial cells are peroxisomes and lysosomes.
False
Sue was monitoring the oil spill into the Gulf of Mexico from an oil tanker. From her observations, she noted that the oil was moving as large patches in the water. It did not appear as though the oil was dissolving into the water. Why did the oil not dissolve into the water?
Hydrophobic interactions
Match the appropriate functional groups to the physical and chemical properties described. Polar, soluble, forms H bonds, forms alcohols.
Hydroxyl Group
Why is it so important that all of the chromosomes align on the metaphase plate during metaphase?
If they cannot, it suggests that they aren't properly attached to the spindle microtubules, and thus won't separate properly during anaphase.
The structure of chlorophyll is shown below. Based on this structure, where would you predict that it would be found in a cell? (image 2.31)
In a membrane because it has a hydrophobic tail and a polar head.
Proteins are three dimensional molecules made of strands of amino acids (imagine a ball of string). There are 20 different amino acids used in proteins found in living organisms. Some of these amino acids are polar and others are nonpolar. Where would a series of nonpolar amino acids most likely be located in a protein that is found in the cytosol of an animal cell?
In the interior of the protein
If you could measure the pH inside a chloroplast, where would it be the lowest?
In the lumen of the thylakoid
A dental student wants to test if fluoride is an effective additive against tooth decay. The student studies tooth decay in a population of people who live in neighborhoods supplied with fluoridated water. This student would like to ask whether access to fluoridated water prevents tooth decay. What would be an effective control group to ask this question?
Individuals with access to water with no fluoride added.
What is the function of the 3' end of the tRNA?
It attaches to the amino acid.
What is the purpose of the C-H rich hydrocarbon tail of chlorophyll?
It can help anchor the pigment to the thylakoid membrane
Why was the determination of the actual sequence of the human genome considered to be descriptive science?
It did not involve hypothesis-driven research.
What oxidizing agent is used to temporarily store high energy electrons harvested from glucose molecules in a series of gradual steps in the cell?
NAD+
What oxidizing agent is used to temporarily store high energy electrons harvested from glucose molecules in a series of gradual steps in the cytoplasm?
NAD+
You eat a bowl of beans as part of your dinner. As you digest the beans, the proteins that are present get broken down to their component amino acids. As your body destroys the macromolecules that were present in the beans, is the energy present in those molecules destroyed?
No. The energy contained within these macromolecules is converted into other forms of chemical energy and kinetic energy, though some is lost as heat.
Match the organelle with its function. Instructions for protein synthesis and cell reproduction; contains genetic information
Nucleus
A mixed solution of water and small molecules is exposed to a cell membrane and allowed to interact for an hour. Which molecule would be most likely to cross the phospholipid bilayer without the aid of transport proteins and diffuse across the membrane the fastest?
O2
During DNA replication, DNA pol III synthesizes the lagging strand in segments, called
Okazaki fragments.
How might a single base substitution in the sequence of a gene affect the amino acid sequence of a protein encoded by a gene, and why?
Only a single amino acid could change, because the reading frame is unaffected.
Which characteristic of life does this best represent? A cat is composed of organ systems, which are composed of organs, which are composed of tissues, which are composed of cells.
Ordered Complexity
Solutes move from regions of high concentrations across the membrane to regions of lower concentrations EXCEPT during
Osmosis
If a cell is placed in an isotonic environment, then
Osmosis still occurs but there is no net gain or loss of cell volume.
Atoms with higher electronegativity hold shared electrons tightly. This can result in polar covalent bonds. Atoms that display such high electronegativity in polar bonds include:
Oxygen & Nitrogen
During translation, the ____ site within the ribosome holds the growing amino acid chain while the ____ site holds the next amino acid to be added to the chain.
P, A
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. What are the genotypes of the gametes that could be produced by a plant that is heterozygous for both traits?
PT, Pt, pT, and pt
Match the appropriate functional groups to the physical and chemical properties described. Contains multiple P-O bonds, found in nucleic acids.
Phosphate Group
Regarding gene expression, which of these accurately distinguish prokaryotes from eukaryotes?
Prokaryotic ribosomes translate mRNA transcripts that are still being synthesized by RNA polymerase.
Luke sprained his ankle, tearing some of the collagen protein that forms his ligaments. Some types of collagen consist of three polypeptide chains twisted together to form a rope-like strand. What level of protein structure does this rope-like strand represent?
Quaternary
What is the first step during transcription initiation in prokaryotes?
RNA polymerase binds to the promoter
Which characteristic of life does this best represent? A bacterial cell divides to form two new cells.
Reproduction
Why is it necessary to take an interdisciplinary approach to studying biology?
Research methods used to solve many biological questions often require a number of different types of approaches and the expertise of a variety of scientists.
Which characteristic of life does this best represent? The roots of a plant grow toward a source of water.
Sensitivity
Match the enzyme to the appropriate function. During replication this protein stabilizes the single stranded template.
Single-stranded binding protein
Which of the following statements concerning enzymes is true? Binding at the active site allows the enzyme to always retain its shape. Enzymes function on their own; they never need cofactors or any sort of regulation. Non-competitive inhibitors compete for the active site. Some enzymes change shape when substrate binds to them. Molecular structure does not determine enzyme function.
Some enzymes change shape when substrate binds to them.
How does termination of translation take place?
Stop codons with no corresponding amino-acid carrying tRNAs are read.
Some students consume large amounts of coffee and so-called energy drinks to help them stay alert when studying. You notice that many who engage in this practice seem to do poorly on exams. Suppose you want to investigate the relationship between caffeine consumption and exam performance. Which of the following statements would be an appropriate hypothesis?
Students who consume large amounts of caffeine while studying will have lower exam scores than those who consume less caffeine.
Match the appropriate functional groups to the physical and chemical properties described. Covalent bonds between these stabilize proteins.
Sulfhydryl Group
Given the sentence "THE FAT CAT ATE THE RED RAT," which of the following would represent a frameshift mutation?
THE FAC ATA TET HER EDR AT
Imagine that you wish to compare two different diets that will be fed to tadpoles raised in a lab. One diet is a meat-based fish food, and the other is the traditional diet of boiled lettuce. You want to see if the meat-based diet will be associated with an increase in the average weight of the tadpoles. In your experiment you keep all other factors, such as tadpole density per pan, temperature, pH, and the amount of food the same. The only difference between your control and experimental groups is the type of food the tadpoles receive. Which is a good hypothesis for this tadpole experiment?
Tadpoles will be larger if fed a meat-based diet.
The Law of Thermodynamics that states that energy cannot be created or destroyed is:
The First Law of Thermodynamics
What is the major structural difference between starch and glycogen?
The amount of branching that occurs in the molecule.
Why is cell division in plants so different from that in animals?
The cell wall around each plant cell prevents constriction of the plasma membrane to cause the cells to divide.
Why do homologous chromosomes pair in prophase I and not in prophase II?
The cells are haploid during prophase II and therefore can't pair.
Which best explains the process of meiosis?
The cells that result from meiosis I are haploid, and each chromosome consists of 2 chromatids.
If two parents do not have an autosomal recessive disease, what can you say about their children?
The children could get the disease if both parents are carriers (heterozygotes).
Compare coffee (pH4) to pure water (pH7). Which of the following is true?
The concentration of H+ ions is 1000 times greater in coffee than water.
How is a control group treated in a scientific experiment?
The control group receives all the same treatments except the experimental variable.
Why are carbohydrates important for energy storage?
The covalent C-H bonds found in carbohydrates store energy.
Dr. Edward Jenner realized that cows have a disease called cowpox, which is like a disease that infects humans called smallpox; Jenner noticed that milkmaids whose hands were infected with cowpox were not contracting smallpox. Jenner infected a child with the pus from a cowpox blister, and found that the child did not contract smallpox. Which statement represents a supporting hypothesis?
The cowpox infection will prevent the child from being infected by the smallpox virus.
What variable(s) influence(s) whether a nonpolar molecule can move across a membrane by passive diffusion?
The difference in concentration of the molecule across the membrane.
As electrons move along the electron transport chain, they lose potential energy. How is the energy that is released used by the cell?
The energy is used to transport protons against their concentration gradient
How did mitochondria and chloroplasts most likely arise?
They arose from bacteria that were engulfed and not digested.
All of the reactions of cellular respiration that occur after glycolysis take place in what part of the eukaryotic cell?
The mitochondria
Many metabolic pathways are ultimately concerned with ATP; either with the generation of ATP, or with the requirement of ATP for that pathway to function. Why is ATP so important to metabolism?
The phosphate groups of ATP are held together by unstable bonds that can be broken to release energy
When an egg is fried, what happens to the protein in the egg?
The protein is denatured.
Which of the following tends to make chemical reactions spontaneous?
The reactants are more ordered than the products.
In a chemical reaction, if the reactants have less free energy than the products,
The reaction will require the input of energy to drive the creation of products.
Which of the following is a VIOLATION of the First Law of Thermodynamics?
The universe will die, and it will have no energy left in it.
Which best describes the process of independent assortment?
The way one pair of homologues lines up along the metaphase plate does not affect how any other pair lines up.
A student set up an experiment to test if plants give off water vapor. Fifty pea plants, growing in pots, were covered with individual glass containers and left overnight. The next morning, the inside of each lid was covered in droplets of water. The lab student concluded that plants generally give off water vapor. What critique would you make of the experimental design?
There was no control so the water could have come from other sources such as air in the jar or the soil.
A current problem in modern medicine is the development of drug resistance mutations. This occurs when a mutation arises in a disease-causing microbe making it resistant to a drug and thus rendering the drug useless in treating a specific disease. Many useful drugs are competitive inhibitors of specific enzymes, and the drug-resistance mutations prevent the binding of the drug. These types of mutations, in addition to preventing competitive inhibitor binding, can also sometimes reduce the activity of the enzyme. Why is that the case?
These mutations most likely change the shape of the active site of the enzyme
Which of the following is NOT a characteristic that chloroplasts and mitochondria share?
They are both part of the endomembrane system.
What are the functions of the cytoskeleton? Check all that apply. To assemble ribosomes To provide scaffolding for the enzymes in certain areas of the cell To organize the cell's activities To provide movement of molecules in the cell To provide the cell shape
To provide scaffolding for the enzymes in certain areas of the cell To organize the cell's activities To provide movement of molecules in the cell To provide the cell shape
If you wanted to test whether or not a particular pain reliever was effective in the general population, you would need to design an experiment with an experimental group and a control group. What should be the only difference between these two groups?
Treatment: The experimental group should get the pain reliever, and the control group should get a placebo
Feedback inhibition occurs when the final product acts as an inhibitor to the first enzyme in the pathway.
True
Mitosis and cytoplasmic division result in the formation of two genetically identical cells.
True
Monosaccharides are linked together to make polysaccharides by dehydration reactions.
True
The spindle checkpoint can be activated by a single unattached kinetochore, preventing anaphase from occurring.
True
True or False: RNA polymerase reads the template strand in the 3' to 5' direction.
True
True or False: An input of energy is required to maintain the complexity of living systems.
True
True or False: Cells are composed of chemicals and both the structure and function of cells are regulated by the basic principles of chemistry.
True
True or False: General transcription factors are required for the majority of eukaryotic transcription events.
True
True or False: Living systems are governed by the same principles of chemistry and physics that govern non-living systems.
True
True or False: Living systems are the most complex chemical systems on earth
True
True or False: The energy conversions that take place in living systems are governed by the same laws of thermodynamics that govern non-living systems.
True
Match the organelle with its function Regulates water levels in plant cells
Vacuole
It is summer, and you are excited about going to your local amusement park, and specifically about riding the new roller coaster that was just built. You imagine waiting at the top of the stairs for the roller coaster to pull into the station, climbing into the car, strapping yourself into the seatbelt, and pulling down the harness. You can imagine the cars slowly chugging up to the top of the first hill, coming down on the other side, and the excitement you expect to feel as you go along for the ride. Of all of the things that you have imagined, which is an example of potential energy?
Waiting at the top of the stairs for the roller coaster to pull into the station
A scientist performs an experiment in which they create an artificial cell with a selectively permeable membrane through which only water can pass. They inject a 5M solution of glucose into the cell and then place the cell into a beaker containing 10M glucose. What effect do you expect to observe?
Water moves out of the cell
How is a concentration gradient established?
When solute concentrations differ on the two sides of the membrane.
A student poses the question: How does the presence of dissolved salt affect the freezing point of water? To answer this question, the student set up two conditions. In the first condition, the student added salt to water in a container and referred to this condition as the variable. In the second condition, the student did not add any salt to water in a second container and referred to this condition as the control. The student took both containers and attempted to freeze the water at various temperatures to assess the freezing point. Would this be a valid experiment?
Yes, because there is one variable and a control
You look outside and realize that your grass needs to be mowed. You pick up the container of gasoline and see that you have approximately a third of a gallon left. You hypothesize that this amount will be enough to mow your entire lawn. Unfortunately, half way through mowing your lawn you run out of gasoline. You grumble and think to yourself that the next time you mow the lawn, you hypothesize that you will need to have at least two-thirds of a gallon of gasoline available. How did the results of your lawn-mowing experience influence the validity of your new hypothesis for future gasoline needs?
Your prediction of future gas needs is based on experimental data and therefore increases the validity of your hypothesis.
Carbohydrates like glycogen and cellulose are polymers. What is a polymer?
a chain of similar building blocks called subunits, or monomers
A scientific theory is:
a concept that is supported by experimental evidence that explains the facts in an area of study.
In aerobic respiration, chemiosmotic generation of ATP is driven by:
a difference in H+ concentration on the two sides of the inner mitochondrial membrane
Water boils at a higher temperature than a non-polar solvent like ether because...
a large amount of energy is required to break the many hydrogen bonds that restrict the movement of individual water molecules.
The synaptonemal complex is
a network of proteins that holds homologues together.
Define nonpolar covalent bond and polar covalent bond. What is different about the chemical characteristics of a molecule that contains at least one polar covalent bond compared to a molecule that contains only nonpolar covalent bonds?
a nonpolar covalent bond is when the atoms have similar electronegativities so neither atom has a partial positive or negative charge. a nonpolar molecule is hydrophobic and does not mix with water. a polar covalent bond is when atoms have different electronegativities so that one atom has a partial positive charge while the other has a partial negative charge. an example of this is a water molecule because the hydrogen atoms have partial positive charges, and the oxygen atom has a partial negative charge because oxygen has a greater electronegativity than hydrogen. a polar molecule will dissolve in water because it is hydrophilic. a molecule that has both polar and nonpolar bonds will result in the molecule folding so that the hydrophobic bonds are on the interior.
The energy needed to destabilize existing chemical bonds and start a chemical reaction is called:
activation energy.
The type of movement that is specific and requires carrier molecules and energy is
active transport.
Which of the following allows more than one type of protein to be produced from one gene?
alternative forms of RNA splicing
Proteins are composed of monomer building blocks called ______ acids.
amino
Plants are raised under artificial lights turned off and on by an electric clock. Some are given long periods of light, others short periods. This is an example of:
an experiment
Living organisms and non-living systems have numerous characteristics in common, but only organisms -
are composed of cells
You are studying cell cycle progression in yeast cells. If you could prevent cdc2 (the yeast CDK) from associating with the mitotic cyclin, the cells would:
arrest in G2
In which of these genotypes would the recessive phenotype be expressed? Assume Mendelian simple dominance.
bb
Hydrogen bonding in water causes water to
be less dense as ice than as liquid water.
Ribosomes can attach to prokaryotic messenger RNA _____________________.
before transcription is complete
The unrestrained, uncontrolled growth of cells in humans leads to the disease called
cancer
Viruses defy characterization as living organisms even though they possess nucleic acids and proteins. The reason why viruses are not considered to be alive is because they
cannot reproduce without a host cell.
On the outer surface of the plasma membrane there are marker molecules that identify the cell type. Often these molecules are
carbohydrate chains.
Where do the carbon atoms in glucose come from?
carbon dioxide (CO2)
Which of the following are functions of proteins? (Select all that apply) catalytic (enzymatic) activity storage of genetic information storage of energy structural support transport of molecules/ions through blood and across plasma membranes
catalytic (enzymatic) activity structural support transport of molecules/ions through blood and across plasma membranes
The simplest level of organization that can carry out all of the functions of life is a(n) ____
cell
Plants, fungi and bacteria all have:
cell walls
Humans are unable to get metabolic energy from cellulose because:
cellulose digesting enzymes are absent from the human gut.
Plant cells often have a large membrane-bound sac that is used for storing water and other substances called a:
central vacuole
What is the name for the position at which the chromosome is constricted so that the sister chromatids are manipulated as a unit?
centromere.
Match each description with the appropriate step in enzyme catalysis.
chap 4 hmwk question 1
The spontaneous formation of a lipid bilayer in an aqueous environment occurs because a. the polar head groups of the phospholipids can interact with water. b. the long fatty acid tails of the phospholipids can interact with water. c. the fatty acid tails of the phospholipids are hydrophobic. d. Both a and c are correct. e. None of these are correct.
d. both a and c are correct
(week 3 hmwk question 1) This diagram illustrates a
dehydration reaction.
Your microwave will not turn on, and you speculate that a circuit breaker in the house has been tripped. In scientific terminology, the steps would be described as:
developing a hypothesis based on an observation.
What is the net movement of substances to regions of lower concentration called?
diffusion
(week 3 hmwk question 1) Sucrose is a
disaccharide.
As a genetic counselor, you are constructing a human pedigree for a particular disease. You note that every generation shows the trait, suggesting that the trait is
dominant
Tetrads (four chromatids) are seen
during meiosis I.
The NADPH required for CO2 fixation is formed
during the light reactions
A biological community together with its physical habitat constitutes a(n) _______
ecosystem
Oxidation and reduction reactions are chemical processes that result in a gain or loss of:
electrons.
A cell in G2 before meiosis begins, compared with one of the four cells produced at the end of meiosis II, has
four times as much DNA and twice as many chromosomes
The amount of energy available to break and form chemical bonds is referred to as a molecule's
free energy.
The energy available to do work in a system is called
free energy.
During osmosis water will move in which direction?
from the area with lower solute concentration to the area of higher solute concentration
The genetic make-up of an organism is called it's __________________.
genotype
(week 3 hmwk question 1) The molecule in this diagram that is commonly used as a transport sugar in humans is
glucose
It is thought that the oldest stage of cellular respiration from an evolutionary perspective is
glycolysis
This process is common to all living cells:
glycolysis
As a result of meiotic division, the chromosome number is
halved
Fats are excellent energy storage molecules because they:
have a relatively high ratio of energy storing C—H bonds.
A defining characteristic of eukaryotic organisms is that they
have their transcription occurring in the nucleus and translation in the cytoplasm.
Capillary action is one of the forces that aids water's upward movement in plants. The narrower the diameter of the tube, the farther the water column will rise. Capillary action is a result of water molecules:
having an adhesive force, which allows them to attach to the vessel walls.
During replication, this enzyme unwinds the DNA helix.
helicase
What type(s) of interactions are important for protein secondary structure? peptide hydrogen ionic disulfide hydrophobic
hydrogen
What type(s) of interactions are important for protein tertiary structure? peptide hydrogen ionic disulfide hydrophobic
hydrogen ionic disulfide hydrophobic
Nitrogen has a higher electronegativity than hydrogen. As a result you would expect that ammonia (NH3) molecules can form ____ with each other.
hydrogen bonds
The two strands of nucleotides in a DNA molecule are held together by
hydrogen bonds between nitrogenous bases.
In the stable form of protein, what is generally oriented to the interior of the protein molecule?
hydrophobic portions
A suggested explanation that might be true and is subject to testing by further observations is a(n):
hypothesis
Label the parts of the DNA replication fork.
image 3.27
The chemistry of living systems representing all chemical reactions is called
metabolism
All of the following increase genetic variation EXCEPT crossing over mutation independent assortment random fertilization mitosis
mitosis
Which of the following produces new cells that are genetically identical to the original cell?
mitosis
The level of organization that is more complex than an atom but less complex than an organelle is a(n)
molecule
(week 3 hmwk question 1) Glucose is a
monosaccharide.
If an individual allele has more than one effect on the phenotype, this is called
pleiotropy
A long chain carbohydrate, such as starch, that is composed of hundreds to thousands of glucose molecules, is called a(n) ________.
polysaccharide
A group of organisms that belong to the same species and live in the same place is called a(n)____
population
You have been assigned to address a problem of overpopulation of species X in a nearby county. One of the members of your team suggests introducing species Y, which is a natural predator of species X, but not normally found in the area. After some discussion, you go ahead and introduce species Y. What aspects of the hierarchical organization may be affected within a period of a several years?
population, species, community
The specific amino acid sequence of a protein is its ____.
primary structure
The segments of DNA where transcription begins have a binding site for RNA polymerase. These segments are known as:
promoters
During which phase of mitosis does the nuclear membrane disappear and the chromosomes become distinct?
prophase
Name the cell cycle stage. (image 3.32)
prophase
What are histones?
proteins that double-stranded DNA molecules wrap around in eukaryotes.
During a redox reaction, the molecule that gains an electron has been
reduced and now has a higher energy level.
An alien from another planet landed on earth. He is fascinated by cars and is determined to figure out how they work. He decides to disassemble one of them and examine each part independently. He removes one of the tires and proceeds to learn all he can about the tire. He then removes one of the headlights and proceeds to learn all he can about the headlight. What type of approach is this alien taking to learn about the car?
reductionism
(week 3 hmwk question 1) The glucose molecule in this diagram is shown in the ____ form.
ring
In a single water molecule, the oxygen and hydrogen atoms
share electrons unequally
During the splicing reaction, the intron-exon junctions are recognized by
snRNPs
Water controls global temperature because it is so abundant and has a high:
specific heat
At what checkpoint(s) does a cell arrest in response to an unattached kinetochore?
spindle (M phase)
Plants store energy as
starch
Which of the following are functions of carbohydrates? (Select all that apply) catalytic activity storage of genetic information storage of energy structural support signaling molecules (such as hormones or neurotransmitters)
storage of energy structural support
Where does the Calvin cycle take place?
stroma
(week 3 hmwk question 1) The molecule in this diagram that is commonly used as a transport sugar in plants is
sucrose
Sulfur atoms have an atomic number of 16 and an atomic mass of 32. How many covalent bonds will sulfur atoms tend to form? Explain your reasoning.
sulfur atoms will form two covalent bonds because it has six valence electrons and it wants to get to eight.
The pairing of chromosomes along their lengths, which is essential for crossing over, is referred to as
synapsis.
During translation, amino acids are carried to the ribosome by
tRNA
Name the cell cycle stage. (image 3.34)
telophase
Membrane fluidity is affected by
temperature, cholesterol, types of fatty acids.
You return home to find that your baby brother has scattered his toy trains and trucks all over the floor of your room. As you begin to pick up the toys and put them away, you realize that even though he is just a baby, he has clearly mastered:
the second law of thermodynamics
In the process of diffusion, molecules move from areas where
their concentration is higher to areas where their concentration is lower until an equilibrium is reached.
When two hydrogen atoms come into contact, they can form a covalent bond. As a result:
their valence shell electrons are shared between nuclei.
Fructose and galactose both have six carbon atoms, twelve hydrogen atoms and six oxygen atoms, just like glucose. A friend of yours says: "Since those sugars have the same number of atoms, they should have the same name." You answer: "While they do have the same number and type of atoms,
they are named differently because they are alternate forms of the monosaccharide, glucose."
A nucleic acid contains adenine, allowing you to conclude that:
this nucleic acid could be either DNA or RNA
A nucleic acid contains thymine, allowing you to conclude that:
this nucleic acid is DNA
Enzymes have similar responses to both changes in temperature and pH. The effect of both is on the
three-dimensional shape of the enzyme.
What region of the chloroplast is associated with the capture of light energy?
thylakoid membrane
A _____ is a group of similar cells that act as a functional unit.
tissue
What is the function of the reactions in a fermentation pathway?
to generate NAD+ from NADH so that glycolysis can continue
The two nitrogen atoms in nitrogen gas (N2) share six electrons forming a _____.
triple covalent bond
Most individuals in academia are basic researchers, funded through research grants from agencies or foundations. Based on your knowledge of applied research, an industrial company would most likely employ individuals
who develop alternative fuel sources.
During DNA replication, this protein helps hold DNA polymerase onto the template strand for efficient replication.
β-clamp