Bio PT 2

A human male has ___ chromosomes with ___ sex chromosomes. A) 46, XY B) 48, XY C) 46, XX D) 48, XX E) 48, YY

A) 46, XY

Which mutation provides a survival advantage? A) A flower that attracts more bees B) A tree that grows shorter than the surrounding trees C) A horse that lacks the ability to digest either grains or grass D) A brightly colored fish that attracts predators E) A shrub that loses the ability to make seeds

A) A flower that attracts more bees

A "mini-gene" has the base sequence TACCCGTGCACG. If the T at the beginning of the sequence is deleted, what will be the consequence? A) All of the codons after that point will be changed B) Only the amino acid coded for in that codon will be changed C) RNA polymerase will skip that codon, but all the others will be read normally. D) RNA polymerase will correct the deletion, and a normal protein will be produced E) The first nucleotide is always replaced anyway, so there will be no change.

A) All of the codons after that point will be changed

Which of these processes occurs in the cytosol? A) Glycolysis B) Electron Transport System C) Krebs Cycle D) Photosynthesis E) Chemiosmosis

A) Glycolysis

Cell walls A) Have many small holes B) Only occur in plant cells C) Dissolve when a plant dies D) Are made primarily from phospholipids E) All of the above

A) Have many small holes

The atoms of a single element A) Have the same number of electrons B) Can form bonds only with atoms of the same element C) Can have different numbers of electrons D) Can have different numbers of protons E) Always have an overall positive charge

A) Have the same number of electrons

What determines the cohesiveness of water molecules? A) Hydrogen bonds B) Ionic bonds C) Covalent bonds D) Hydrophobic interactions E) High heat of vaporization

A) Hydrogen bonds

Fish sperm consists mostly of the male fish's DNA. If tested chemically, there would be relatively high amounts of A) Nitrogenous bases, sugar and phosphate groups B) Phospholipids and steroids C) Triglycerides and ATP D) Proteins and stored fats E) Amino acids and unsaturated fats

A) Nitrogenous bases, sugar and phosphate groups

The "first cells" shown at the bottom of this illustration most likely refer to: A) Prokaryotes. B) Animals. C) Plants. D) Fungi. E) Protists.

A) Prokaryotes.

During which stage of meiosis does crossing-over occur? A) Prophase 1 B) Metaphase 1 C) Anaphase 11 D) Prophase 11 E) Metaphase 11

A) Prophase 1

How are amino acids and proteins related? A) Proteins are made up of chains of amino acids B) Amino acids are formed by joining together many proteins C) Proteins are a portion of an amino acid D) Proteins are chains of carbohydrates; amino acids are a type of lipid E) Amino acids are similar to fatty acids

A) Proteins are made up of chains of amino acids

Which of the following are both universal characteristics of life? A) The ability to grow and the ability to reproduce using DNA B) The ability to reproduce using DNA and the ability to capture energy from the sun C) The ability to move and the ability to sense the environment D) The ability to grow and the ability to think E) The ability to reproduce and the ability to sleep

A) The ability to grow and the ability to reproduce using DNA

Which of the following does NOT describe a chemical reaction? A) The products are placed to the left of the arrow B) The reactants are placed to the left of the arrow C) The arrow represents the direction in which the reaction proceeds D) Atoms must be balanced on both sides of the equation E) All of the above are true

A) The products are placed to the left of the arrow

During the Krebs cycle: A) The products of glycolysis are further broken down, generating additional ATP and NADH molecules B) High-energy electron carriers pass their energy to molecules of sugar, which store them as potential energy C) Cellular respiration can continue even in the absence of oxygen D) Pyruvate molecules are converted to lactate E) NADH gets oxidized to NAD+

A) The products of glycolysis are further broken down, generating additional ATP and NADH molecules

The process of converting the "message" of mRNA into a sequence of amino acids is called: A) Translation B) Transcription C) Replication D) Activation E) Duplication

A) Translation

The cell formed through fertilization is called a/an A) Zygote B) Gamete C) Sperm cell D) Ovum E) Egg cell

A) Zygote

Which does not occur in telophase? A) Cytokinesis is under way B) The nuclear membrane is being reconstructed C) The centromeres split apart D) Chromosomes de-condense into chromatin E) The nucleolus reforms

C) The centromeres split apart

From your knowledge of the function of lysosomes, the pH of lysosomes is likely to be A) Always changing D) 9 B) 5 E) 12 C) Neutral

B) 5

Which point mutation would be most likely to have a catastrophic effect? A) A base substitution B) A base deletion near the start of the coding sequence C) The deletion of three bases near the start of the coding sequence D) A base deletion near the end of the coding sequence E) A base deletion at the very end of the coding sequence

B) A base deletion near the start of the coding sequence

In plant cells, chloroplasts A) Serve the same purpose as mitochondria do in animal cells B) Are the site of conversion of light energy into chemical energy C) Play an important role in the breakdown of plant toxins D) Generate turgor pressure E) A and B are correct

B) Are the site of conversion of light energy into chemical energy

To test the effect of vitamin D on growth, two groups of rats were raised under identical conditions and fed the same diet. One of the groups received daily injections of vitamin D. The other group received injections of saline, which did not contain vitamin D. All the rats were weighed weekly for 2 months. In this experiment, the control was the: A) Group receiving vitamin D. B) Group receiving saline. C) Average weight gain of the rats. D) 2-month period of time. E) The diet the rats ate

B) Group receiving saline.

If a reaction results in one molecule losing an electron and a second molecule gaining that electron, the electron donor is said to be A) Reduced B) Oxidized C) Transformed D) Activated E) Inhibited

B) Oxidized

The movement of molecules across a membrane from an area of higher concentration (of the molecule)to an area of lower concentration is best described as A) Osmosis B) Passive transport C) Active transport D) Electron transport E) Receptor-mediated endocytosis

B) Passive transport

Which of the following statements about prokaryotes is incorrect? A) Prokaryotes appeared on earth before eukaryotes B) Prokaryotes have circular pieces of DNA within their nuclei C) Prokaryotes contain cytoplasm D) Prokaryotes contain ribosomes E) Some prokaryotes con photosynthesize

B) Prokaryotes have circular pieces of DNA within their nuclei

Which sequence of stages in mitosis is correct? A) Prophase, anaphase, metaphase, telophase B) Prophase, metaphase, anaphase, telophase C) Anaphase, metaphase, telophase, prophase D) Anaphase, prophase, telophase, metaphase E) Prophase, telophase, anaphase, metaphase

B) Prophase, metaphase, anaphase, telophase

Which of the following statements about DNA replication is NOT correct? A) The DNA molecule unwinds as the hydrogen bonds are broken B) Replication occurs as each base is paired with one exactly like it C) The process is known as semiconservative replication because one old strand is conserved in the new molecule D) The enzyme that replicates the DNA is DNA polymerase E) The enzyme that links the Okazaki fragments together is DNA ligase

B) Replication occurs as each base is paired with one exactly like it

Large biological molecules are synthesized by removal of A) Carbon B) Covalent bonds C) Water D) Oxygen E) Peptides

C) Water

Which of the classes of RNA molecules carries the amino acids that are added to the growing polypeptide chain? A) Ribosomal RNA B) Transfer RNA C) Messenger RNA D) Primary RNA E) Secondary RNA

B) Transfer RNA

In an analysis of the nucleotide composition of DNA to see which bases are equivalent in amount, which of the following is true? A) A = C B) A = G and C = T C) A + C = G + T D) A + T = C + G E) G = T

C) A + C = G + T

Suppose one strand of a "mini-gene" has the base sequence TACCCGGATTCA. The last codon in the mRNA sequence will be: A) UGA B) AGT C) AGU D) TCA E) ACT

C) AGU

Which organism is least likely to survive to reproduce? A) A flower that produces a scent that attracts bees B) A shrub that produces a toxin in its flower buds that repels deer C) An animal with a mutation that causes skin color to be more noticeable D) A dark-furred rodent that comes out only at night E) a seahorse that mimics the weeds in which it lives

C) An animal with a mutation that causes skin color to be more noticeable

If enzymes were used during a reaction, which of the following could be added to a system to make the reaction occur faster? A) Water B) A decrease in temperature C) An small increase in heat energy D) End products E) All of the above

C) An small increase in heat energy

A primary source of scientific results is ___ A) The news media B) Anecdotes from others C) Articles in peer- reviewed journals D) The internet E) All of the above

C) Articles in peer- reviewed journals

Which of the following levels of organization is the most inclusive? A) Organism B) Population C) Biosphere D) Community E) Ecosystem

C) Biosphere

What bond is (are) easily disrupted in aqueous (water) solutions? A) Covalent B) Polar covalent C) Ionic D) A and B are correct E) A, B, and C are correct

C) Ionic

Evolution: A) Occurs too slowly to be observed B) Can occur in the wild but not in the laboratory C) Is responsibility for the increased occurrence of antibiotic-resistant bacteria D) Is unrelated to mutations in DNA E) All of the above are correct

C) Is responsibility for the increased occurrence of antibiotic-resistant bacteria

What is the significance of the conversion of pyruvate to lactate during fermentation? A) Pyruvate becomes available to enter the mitochondrial matrix B) The citric acid/Krebs cycle is initiated C) NAD+ is regenerated for use in glycolysis D) ATP is produced E) The energy in pyruvate is used up

C) NAD+ is regenerated for use in glycolysis

A chemical compound that releases H+ into a solution is called: A) A proton B) A base C) an acid D) A hydroxide ion E) A hydrogen ion

C) an acid

A neutral solution has A) No H+ B) No OH- C) equal amounts of H+ and OH- D) No pH E) A pH of 0

C) equal amounts of H+ and OH-

A molecule of glucose has the molecular formula C6H12O6. Therefore it has __ atoms. A) 3 B) 12 C) 6 D) 24 E) None of the above

D) 24

A guess in a scientific process is called __; a unifying explanation for a range of observations is termed___? A) Theory: Hypothesis B) Theory: Experiment C) Hypothesis: Control D) Hypothesis: Theory E) Experiment: Theory

D) Hypothesis: Theory

Prior to protein synthesis, the DNA A) Attracts tRNAs with appropriate amino acids B) Must first undergo replication C) Contains anticodons that must become codons D) Serves as a template for the production of mRNA E) Attaches to ribosomes for protein synthesis

D) Serves as a template for the production of mRNA

Which of the following is NOT one of the four most common elements found in living organisms? A) Hydrogen B) Carbon C) Oxygen D) Sulfur E) Nitrogen

D) Sulfur

Traits controlled by sex-linked recessive genes are expressed more often in males because: A) Males inherit these genes from their fathers B) Males always carry two copies of these genes C) All male offspring of a female carrier get the gene D) The male has only one copy of these genes E) Males get more copies of recessive genes than females do

D) The male has only one copy of these genes

If a species contains 40% guanine in its DNA, what is the percentage of adenine that it would contain? A) 40% B) 60% C) 100% D) 20% E) 10%

E) 10%

The second orbital shell of an atom can hold ___ electrons A) 2 B) 3 C) 4 D) 6 E) 8

E) 8

A lipid is a polymer made up of which kind of monomers? A) Glucose or modified glucose molecules B) Amino Acids C) Nucleotides D) Alternating sugar and phosphate groups E) Fatty acids and glycerol

E) Fatty acids and glycerol

The anaerobic breakdown of glucose is called A) Glycolysis B) Electron Transport System C) Krebs Cycle D) Photosynthesis E) Fermentation

E) Fermentation

Which statement is NOT true about x-linked characteristics? A) More males than females are affected B) If a female has the characteristic, all her sons will show it C) Females can be carriers of the gene without showing it D) The characteristic often skips a generation, from a woman's father to her son E) Males can have two copies of the allele for the trait, but females only have one

E) Males can have two copies of the allele for the trait, but females only have one

In a phospholipid bilayer, the A) Phosphate groups are hydrophobic B) Fatty acids tails are ionized C) Fatty acid tails are hydrophilic D) Proteins are located only between the two phospholipid bilayers E) Phosphate heads are oriented toward the exterior of the cell or toward the cytoplasm

E) Phosphate heads are oriented toward the exterior of the cell or toward the cytoplasm