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Biology Practice Test #6

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In a eukaryotic cell, which organelle produces transport vesicles for exocytosis?

2 / 40

Which of the following properties is responsible for holding together the water molecules in a vertical column of water in xylem vessels of a plant?

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DNA that is synthesized from messenger RNA molecules and used to recreate the genomic library is commonly referred to as, which of the following?

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When similar evolutionary changes occurring in two species that can be related or unrelated this is known as

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Two unrelated species evolve in a way that makes them more similar. This is known as

6 / 40

What activates adenylyl cyclase (AC)?

7 / 40

A chemiosmotic gradient is generated in both cellular respiration and photosynthesis. The gradient is generated as electrons pass along an electron transport chain in membranes of mitochondria and chloroplasts. Which of the following correctly describes the origin of these electrons as they enter the electron transport chain and the endpoint when they leave the electron transport chain?

8 / 40

The velocity of nerve impulse propagation could be increased by:

9 / 40

Microtubules are essential components of which of the following structures?

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The normal pH of the cytosol is about 7.2. Most enzymes in the lysosome, however, are only active at a pH of 5. This suggests that

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Which of the following is NOT classified correctly?

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The fluidity of the plasma membrane can vary in response to temperature changes. For bacteria and yeast cells, which of the following would be a viable strategy to maintain homeostasis of the plasma membrane in a temperature-varying environment?

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Which of the following is most responsible for the separation of pigments on the chromatography paper?

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ADH is a hormone secreted by the kidneys that reduce the amount of water excreted in the urine. ADH is released in times of dehydration. This is an example of

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Because caffeine has a structure very similar to adenosine, it can bind to the adenosine receptor but cannot activate it. Which of the following best describes the effect of caffeine when it binds to the adenosine receptor?

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Which of the following is sometimes referred “programmed cell death” because it leads to organized destruction of the cell?

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A male who is homozygous dominant for hair texture has straight hair. His brother, who is heterozygous for hair texture also has straight hair. This phenotypic similarity is a result of which of the following?

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Which of the following would be an example of a bryophyte?

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Which of the following are responsible for the alignment of the chromosomes along the metaphase plate (equatorial plate) during mitosis?

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Which of the following functions would you NOT expect to result from the secretion of glucocorticoids (i.e. cortisol) by the adrenal glands?

21 / 40

Histones are a kind of protein that is known to play a very important role in packaging DNA into chromatin. What of the following characteristics about histones is true?

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A particle that can bind in the active site of an enzyme, preventing the binding of the substrate is referred to as which of the following?


23 / 40

Which of the following structures of the skeletal system is innervated?

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Which of the following molecules is amphipathic?

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Viral transduction is the process by which viruses carry bacterial DNA from one bacterial cell to another. In what way does this process play a role in bacterial evolution?

26 / 40

Bacteria that are unable to live in the presence of oxygen are referred to as:

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The structure of ATP synthase in the plasma membranes of bacteria is nearly identical to that in the mitochondria and chloroplasts of eukaryotic cells. This similarity best supports which of the following hypotheses?

28 / 40

The cytoplasm divides during which of the following stages of M-phase in the cell cycle?

29 / 40

Which of the following statements is NOT true regarding gastrin secretion and function?

30 / 40

A mutation in a bacterial enzyme changed a previously polar amino acid into a nonpolar amino acid. This amino acid was located at a site distant from the enzyme’s active site. How might this mutation alter the enzyme’s substrate specificity?

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In general, the hormone epinephrine (adrenaline) causes increases in blood pressure, breathing rate, and the rate of cell metabolism—all activities associated with the fight-or-flight response. Like adenosine, epinephrine is also a ligand for a G protein-coupled receptor. Though different from adenosine in other respects, the epinephrine signal transduction pathway, like that of adenosine, produces cAMP and activates PKA. Which of the following is most likely the mechanism that describes how epinephrine works?

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If an inhibitor is able to bind to the active site and block the attachment of the substrate to the enzyme, this is an example of

33 / 40

In the vertebrate nervous system, the term “Node of Ranvier” refers to:

34 / 40

A neuron communicates by sending an action potential down its axon and releasing neurotransmitters. Which of the following correctly describes the process of an action potential. (1) rapidly enters the cell causing a depolarization, followed by the efflux of (2), which repolarizes the cell. Once the action potential reaches the presynaptic terminal, (3) enters the cell, which causes the release of neurotransmitters?

35 / 40

A scientist translates an enzyme from pre-processed cell mRNA in a test tube (in vitro). However, the in vitro enzyme is found to be inactive compared to the extracted in vivo enzyme from a live cell culture. Which statement is the LEAST likely explanation for this phenomenon?

36 / 40

What kind of inheritable condition does this pedigree appear to show?

37 / 40

The transfer of DNA between two bacterial cells connected by sex pili is known as

38 / 40

An inability to produce melatonin would be a defect in which of the following glands?

39 / 40

A form of species interaction in which one of the species benefits while the other is unaffected is called

40 / 40

Trypsin is a proteolytic enzyme secreted by the pancreas in an inactive form (trypsinogen). Trypsinogen can be converted to trypsin by the action of:

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