Biology Unit 3

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Which of the following statements regarding the movement of electrons during cellular respiration is true?

O2 is reduced when it accepts electrons and forms water.

Which of the following statements regarding the movement of electrons during cellular respiration is true?

O2 is reduced when it accepts electrons and forms water. Submit

In which cell would you find the most smooth endoplasmic reticulum (Smooth ER)?

Ovarian cell that produces the steroid (lipid) hormone estrogen

What chemical characteristic of the element oxygen accounts for its function in cellular respiration?

Oxygen is extremely electronegative , making it very powerful in pulling electrons down the electron transport chain.

In which cell would you find the most rough endoplasmic reticulum (Rough ER)?

Pancreatic cell that secretes protein molecules

Which of the following statements regarding photosynthesis and cellular respiration is true?

Photosynthesis occurs in chloroplasts, and cellular respiration occurs in mitochondria. Submit

cellular respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

________ cells lack a membrane-enclosed nucleus.

Prokaryotic

Meiosis 2: Anaphase 2

Sister chromatids separate and chromosomes move toward opposite poles

The cells of an ant and a horse are, on average, the same small size; a horse just has more of them. What is the main advantage of small cell size?

Small cells can more efficiently take up oxygen and nutrients from their surroundings

Coenzyme A (acetyl CoA)

Pyruvic Acid reacts with a molecule of _______ __ to form _______ ____.

Centromere

Region of a chromosome where the two sister chromatids attach

aerobic respiration

Respiration that requires oxygen

Mitosis allows for

- organisms to repair tissues - organisms to reproduce asexually. -organisms to grow.

Which of the following is a carboxyl group? -COOH -C-O -OH -NH2

-COOH

Many names for sugars end in the suffix -hyde. -acid. -ase -ose

-ose

Peptide bonds are used to form amino acids. are formed by a hydrolysis reaction. form between fatty acids .link amino acids.

.link amino acids.

Asexual reproduction requires ________ individual(s).

A normal human sperm cell contains

1 of each autosome and an X chromosome

Five main stages of mitosis

1) Prophase: - Chromatin fibers become more tightly coiled and folded forming dicrete chromosomes inside the nucleus. - Each duplicated chromosome appears as two identical sister chromatids joined together at the waist by the centromere - Mitotic spindle begins to form and microtubules grow out from the centrosomes 2) Prometaphase - Nuclear envelope breaks into fragments and disappears - Sister chromatids are highly condensed - Each sister chromatid has a protein structure called a kinetochore which some of the spindle microtubules attatch to, throwing the chromosomes into agitated motion 3) Metaphase - Mitotic spindle is fully formed and has poles at opposite ends of the cell (football shaped structure that guides the separation of the two sets of daughter chromosomes) - Chromosomes convene on the metaphase plate - Centromeres of all the chromosomes are lined up on the metaphase plate - Kinetochores of the two sister chromatids face opposite poles of the spindle. 4) Anaphase - The sister chromatids separate when the centromeres of each chromosome come apart - Each sister chromatid is now a full-fledged (daughter) chromosome - The cell elongates as the poles are moved farther apart due to some of the microtubules lengthening 5) Telophase - Reverse of prophase - Chromatin fiber of each chromosome uncoil - Mitotic spindle disappears - The equal division of one nucleus into two genetically identical daughter cells (mitosis) is now finished

A normal size range for a typical eukaryotic cell is _____.

10 to 100 micrometers

Baker's yeast is an organism with 32 chromosomes that can perform asexual or sexual reproduction and exist as both a diploid and haploid cell. After meiosis, how many chromosomes will be present in each cell?

16 During sexual reproduction, meiosis reduces chromosome number by one-half, or to 16 in the case of yeast. This is because each chromosome is paired in a diploid cell and meiosis produces four haploid cells.

The amount of DNA in a cell's nucleus doubles during this phase

S phase

The chromosomes are duplicated during the

S phase

The genetic material is duplicated during

S phase

How many different kinds of amino acids are there in most proteins? 100 4 26 20

How many pairs of autosomes do humans have?

how many pairs of autosomes do humans have?

22 pairs

A human female liver cell contains:

22 pairs of autosomes, plus 2 X chromosomes

Cellular respiration can produce up to

32 ATP molecules for each glucose molecule, a capture of about 34% of the energy originally stored in glucose.

The eyepiece of a light microscope has a magnification level of 10x. If you were looking at a paramecium under the lowest-power objective (4x), what would be the total magnification of the microscope at this setting?

40x

A human somatic cell contains _____ chromosomes.

A normal human zygote has

46 chromosomes

An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many electrons does boron have? 2 11 15 5

In a cell containing 10 chromosomes, meiosis results in the formation of daughter cells containing _____ chromosomes.

What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons? 12 0 6 18 -1

An element has 8 protons, 9 neutrons, and 8 electrons. Its atomic number and its mass number, respectively, are _____. 8 and 17 9 and 17 8 and 16 9 and 16

8 and 17

Imagine that a human skin cell went through mitosis but did not undergo cytokinesis. How many chromosomes would be in the cell?

92 When the cell prepared to divide, the chromosomes were replicated, and the chromosome number went from 46 to 92. Because these were not separated into daughter cells during cytokinesis, the cell still has 92 chromosomes.

diploid cell

A cell containing two sets of chromosomes (2n), one set inherited from each parent.

redox reaction

A chemical reaction involving the transfer of one or more electrons from one reactant to another

A child dies following a series of chronic bacterial infections. At the autopsy, the physicians are startled to see that the child's white blood cells are loaded with vacuoles containing intact bacteria. Which of the following explanations could account for this finding?

A defect in the lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria.

Explain how nondisjunction could result in a diploid gamete.

A diploid gamete would result if the nondisjunction affected all the chromosomes during one of the meiotic divisions.

binary fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

Gene

A segment of DNA on a chromosome that codes for a specific trait

electron transport chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.

Meiosis 2: Prophase 2

A spindle forms and moves chromosomes toward the middle of the cell.

exergonic reaction

A spontaneous chemical reaction in which there is a net release of free energy.

kilocalorie (kcal)

A thousand calories; the amount of heat energy required to raise the temperature of 1 kg of water by 1°C.

The purpose of cellular respiration is the production of __________.

ATP

Most cellular work is accomplished by _____ energizing molecules by _____ them.

ATP ... phosphorylating

During chemiosmosis,

ATP is synthesized when H+ ions move through a channel in ATP synthase.

Which of the following is an accurate comparison of active transport and facilitated diffusion?

Active transport moves solutes against their concentration gradient; facilitated diffusion moves substances down their concentration gradient.

__________ reactions turn __________ into __________.

All are correct

Which of the following statements about the properties of life is false? All organisms have the ability to reproduce. All organisms have the ability to take in energy and use it. All organisms have the ability to respond to stimuli from the environment. All organisms have the ability to maintain a constant internal temperature.

All organisms have the ability to maintain a constant internal temperature.

Which of the following statements is false?

An X chromosome is an autosome.

What could you add to pool water to lower its pH? A nonpolar substance A base An acid Glucose A salt

An acid

Drug-resistant tuberculosis is a major health issue in many countries. Treatment for these resistant forms of bacteria is longer and requires more expensive antibiotics. Scientists attribute this to natural selection. Under these circumstances, what does natural selection mean? The tuberculosis genes mutated to avoid being killed by the antibiotic. An environment was created in which the tuberculosis bacterium carrying the antibiotic-resistant genes had an increased likelihood of survival and reproduction. The antibiotic changed the DNA of the tuberculosis bacterium. Tuberculosis bacteria discovered a way to avoid these particular antibiotics.

An environment was created in which the tuberculosis bacterium carrying the antibiotic-resistant genes had an increased likelihood of survival and reproduction.

somatic cells

Any cells in the body other than reproductive cells

Green olives may be preserved in brine, which is a 20-30% salt solution. How does this method prevent contamination by microorganisms?

Bacteria can't survive in a hypertonic solution because they lose water.

Which of the following is not an example of evolution that has resulted from human activity? Some insect species are now resistant to pesticides. Because of hunting, species such as bears and wolves are in danger of extinction. Many strains of bacteria are now resistant to some commonly used antibiotics. Like certain other crops, domesticated strawberries are larger than wild strawberries.

Because of hunting, species such as bears and wolves are in danger of extinction.

The four most common elements in living organisms are C, H, O, Na. C, N, O, Na. C, H, O, N. C, H, O, Fe.

C, H, O, N.

The overall equation for the cellular respiration of glucose is

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy.

Cellular respiration, or the oxidization of glucose, involves the release of

CO2

The runner's bloodstream and lungs also perform the vital function of disposing of

CO2, the waste in cellular respiration

CAN'T pass directly through a phospholipid bilayer:

Ca++ ions

The "backbone" or "skeleton" or "framework" of biological molecules like proteins and fats is made of _________.

Carbon atoms

Which of the following statements regarding carbon is false? Carbon has a tendency to form covalent bonds. Carbon has the ability to bond together to form extensive branched or unbranched "carbon skeletons. Carbon has the ability to bond with up to six other atoms. Carbon has the capacity to form single and double bonds.

Carbon has the ability to bond with up to six other atoms.

In which cell would you find the most tight junctions?

Cell in tissue layer lining the intestine

Meiosis I: Interphase

Cells undergo a round of DNA replication, forming duplicate chromosomes

Which of the following statements about the energy yields from cellular respiration is true?

Cellular respiration is more efficient at harnessing energy from glucose than car engines are at harnessing energy from gasoline.

Meiosis: Telophase I and Cytokinesis

Chromosomes gather at the poles of the cells. the cytoplasm divides. Nuclear cell membrane encloses the chromosomes.

How does inhibition of an enzyme-catalyzed reaction by a competitive inhibitor differ from inhibition by a noncompetitive inhibitor?

Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site.

citric acid cycle

Completes the breakdown of glucose by oxidizing a derivative of pyruvate to carbon dioxide.

The pH of the water in your swimming pool is supposed to be 7, but your pH meter shows you that it's actually at pH 8. This means that the pool water:

Contains too few Hydrogen ions (H+)

Which of the following statements regarding the differences between mitosis and meiosis is false?

Crossing over is a phenomenon that creates genetic diversity during mitosis.

Which of the following statements regarding the differences between mitosis and meiosis is false?

Crossing over is a phenomenon that creates genetic diversity during mitosis. Submit

Information dictating the primary sequence of a polypeptide is permanently maintained within a cell in which of the following forms? RNA DNA amino acids protein

DNA

Genes are made of _________, and can be thought of as blueprints for making _________.

DNA...proteins

Allele

Different forms of a gene

Which of the following questions might best be answered by the methods of hypothesis-based science? (i.e. can be answered by doing controlled experiments)? How many kinds of tissues make up the kidney? How many leopards inhabit the Sabi Sands Reserve of southern Africa? Does the vitamin biotin prevent birth defects? Do human beings have free will?Are there diseases caused by evil spirits?

Does the vitamin biotin prevent birth defects?

Meiosis 2: Metaphase 2

Duplicated chromosomes align at the cell equator like they are in mitosis.

A child is brought to the hospital with a fever of 107°F. Doctors immediately order an ice bath to lower the child's temperature. Which of the following statements offers the most logical explanation for this action?

Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions.

Which of the following statements regarding enzyme function is false?

Enzymes are used up when they catalyze a chemical reaction so must be synthesized for each new chemical reaction.

Which of the following statements about evolution is true? Evolution can result in adaptations. Individuals evolve within the span of their own lifetimes. Organisms evolve structures in response to needs. Evolution is deliberate and purposeful.

Evolution can result in adaptations.

What is the basic difference between exergonic and endergonic reactions?

Exergonic reactions release energy; endergonic reactions absorb it.

A skin cell of a red fox has 34 chromosomes. You look at the cell under a microscope and see that it has 34 chromosomes and one nucleus. Several hours later, you look at the same cell again and see that it has double the amount of DNA and one nucleus. A little while later, you see that it has 68 chromosomes and two nuclei. What stage of the cell cycle was this cell in when you viewed it at each time point?

First view: G1; second view: G2; third view: telophase Submit

In skin cells, lasts for a few hours; in most nerve cells, lasts for decades

G-1 phase

Liver cells and muscle cells make this energy-storage molecule:

Glycogen

After reading the paragraph, answer the question(s) that follow.The National Institutes of Health (NIH) set up a study to determine whether large doses of vitamin C would shorten the length of time it takes to recover from a cold. Three thousand volunteers were split into two groups. For two weeks, members of Group A took 3,000 mg of vitamin C daily. Group B received 3,000 mg of a placebo. At the end of the two-week period, the researchers inserted live cold viruses directly into the noses of all the volunteers. The volunteers in both Group A and B continued to take their daily pills. All the volunteers got colds, and there was no significant difference in the length of time the colds lasted. Which was the experimental group? Group A only Group B only all 3,000 volunteers the researchers that inserted the cold virus

Group A only

Arrange these in order from SMALLEST to LARGEST:

H atom, O atom, water molecule, glucose molecule, protein molecule

Atoms of different Phosphorus isotopes (e.g. P-31, P-32, and P-33):

Have different numbers of neutrons

thermal energy

Heat energy

When the human virus, HIV, first appeared, the mortality rate was close to 100%. However, recent information shows some individuals are unaffected by the virus. Why is this not surprising? New pharmaceutical medicines were produced that were more effective. Humans are genetically diverse, and some are immune to the virus. The virus mutated through natural selection. Individuals started to use protective measures more frequently.

Humans are genetically diverse, and some are immune to the virus.

How is your breathing related to your cellular respiration?

In breathing, CO2 and O2 are exchanged between your lungs and the air. In cellular respiration, cells use the O2 obtained through breathing to break down fuel, releasing CO2 as a waste product.

In cellular respiration, glucose _____ electrons, whereas _____ electrons.

Which of the following statements regarding mitosis and meiosis is true?

In metaphase of mitosis and metaphase I of meiosis, homologous chromosomes separate.

A group of single cell organisms collected from the ocean was brought into the lab for examination. The lab assistant was concerned that the water had become full of toxic waste products and so added clean water to the culture. All of the organisms died, and when she looked at them under the microscope, all she could see were bits and pieces of them scattered throughout the water. What likely happened?

She added water that was hypotonic to the culture of organisms, and they ruptured.

Which of the following statements is not consistent with Darwin's theory of natural selection? Individuals in a population exhibit variations, some of which are passed from parents to offspring. Factors in the environment result in some organisms having better reproductive success than others. Individual organisms exhibit genetic change during their life spans to better fit their environment. Natural selection can lead to the appearance of new species.

Individual organisms exhibit genetic change during their life spans to better fit their environment.

How are ionic bonds formed? Ionic bonds are formed by the give and take of electrons. Ionic bonds are formed by the transfer of a hydrogen atom from one molecule to another. In ionic bonds, one atom gives up an electron to a second atom. Ionic bonds are formed only between isotopes. Ionic bonds are formed when electrons are shared.

Ionic bonds are formed by the transfer of a hydrogen atom from one molecule to another.

What happens to the shape and function of a protein if one of the amino acids is replaced with a different type of amino acid? The protein will unravel and become entirely nonfunctional. It depends on the role of the amino acid that is altered. One amino acid might be replaced with no measurable effect on the protein's function; replacing another might cause a total loss of function. The protein will remain unchanged; several amino acids would have to be altered to have any effect on protein function. The protein's fourth-level structure will be damaged.

It depends on the role of the amino acid that is altered. One amino acid might be replaced with no measurable effect on the protein's function; replacing another might cause a total loss of function.

A fatty acid is an "acid" because:

It has a carboxyl group that donates a Hydrogen ion to a solution

Which of the following statements about lysosomes is false?

Lysosomes synthesize proteins from the recycled amino acids.

Which of the following statements regarding mitosis and meiosis is false?

Meiosis provides for asexual reproduction.

A cell from a diploid organism has the haploid number of chromosomes, but each chromosome has two chromatids. The chromosomes are arranged singly at the center of the spindle. What is the meiotic stage?

Metaphase II (because the chromosomes line up two by two in metaphase I)

Chromosomes are "condensed" and thus can be seen in the light microscope

Mitosis

Chromosomes are being organized and split apart into 2 identical groups

Mitosis

Which of the following statements regarding the function of mitosis is false?

Mitosis allows organisms to generate genetic diversity.

Which of the following statements regarding mitosis and meiosis is false?

Mitosis produces daughter cells with half the number of chromosomes as the parent cell. Submit

Which of the following statements regarding the function of mitosis is false?

Mitosis promotes genetic diversity.

In which cell would you find the most mitochondria?

Muscle cell in the thigh of a long-distance runner

The electron transport chain is, in essence, a series of redox reactions that conclude cellular respiration. During these redox reactions, _____.

NADH is oxidized, which then reduces an electron acceptor in the electron transport chain

The electron transport chain is, in essence, a series of redox reactions that conclude cellular respiration. During these redox reactions, _____.

NADH is oxidized, which then reduces an electron acceptor in the electron transport chain Submit

During fermentation, __________ that was produced during glycolysis is converted back to __________.

NADH; NAD+

Which of the following is an amino group? -COOH -NH2 -OH -CO

NH2

Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?

Na+

TRIS is a commonly used laboratory chemical. An aqueous solution of TRIS has a pH of 7.8. When you add an acid to this solution, its pH does not change very much. Likewise, when you add a base to this solution, its pH does not change very much. This information tells you that:

TRIS is a buffer

How do your cells extract energy from fuel molecules?

The answer involves the transfer of electrons.

In the figure below, what leads directly to the reproductive success of these beetles? All the beetles are reproducing in great numbers. Some of the beetles found a better habitat than the others. The beetles' natural predators are dying out. The beetles with traits best suited to the environment survive.

The beetles with traits best suited to the environment survive.

Why are sweating and other body-cooling mechanisms necessary during vigorous exercise?

The demand for ATP is supported by an increased rate of cellular respiration, but about 66% of the energy released from food produces heat instead of ATP.

Aspirin and other nonsteroidal anti-inflammatory drugs (NSAID)inhibit inflammation by inhibiting an enzyme in the prostaglandin pathway, but by inhibiting this enzyme and this pathway they also inhibit pathways that protect the stomach from damage by stomach acid and that prevent aggregation of blood platelets to form blood clots. What can you conclude from this?

The enzyme is found in many different types of cells

What is the relationship between the Golgi apparatus and the plasma membrane?

The finished products of the Golgi apparatus may leave the cell through vesicles that fuse with the plasma membrane.

G1 phase

The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins.

Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why?

The intestinal cells are bound together by tight junctions.

The pH of human blood is maintained at around pH 7.4. Why does a buffer system need to be present in blood to protect against changes in pH due to increases in acids? Our blood is not exposed to any bases. The metabolic processes of the body produce more acids than bases. Adding bases doesn't alter the pH of most solutions significantly. Under normal conditions, only acids need to be buffered.

The metabolic processes of the body produce more acids than bases.

Two proteins have the same number and type of amino acids. How is it that they can have different shapes and therefore different functions? The proteins were made in different locations in the cell. The proteins were made at different times within the cell. The order in which the amino acids are arranged differs between the two proteins. The proteins have been chemically modified.

The order in which the amino acids are arranged differs between the two proteins.

A diabetic, who does not utilize insulin properly, will metabolize fats instead of glucose. A condition called diabetic ketoacidosis is a common result of excessive fat metabolism, causing blood pH values of 7.1 or less (normal range is 7.35-7.45). What has happened to the blood pH and why? The pH is below normal because buffers can donate OH+. The pH is not affected because the blood buffers can absorb the excess H+. The pH is above normal (basic) because the ketones are too basic. The pH is below normal (acidic) because the buffering capacity was exceeded.

The pH is below normal (acidic) because the buffering capacity was exceeded.

The M phase of mitosis and M phase of meiosis both occur after interphase. However, the two processes differ in the arrangement and behavior of their chromosomes. How?

The pairing up of homologous chromosomes and crossing over only occur during meiosis.

oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.

Your first big biology exam is coming up in a few days, and in order to prepare for late-night study sessions, you buy a box of Yummies, a delicious type of snack cake. After checking out the nutrition facts label on the side of the box, you discover that a single Yummie cake contains 4.5 grams of total fat, 27 grams of carbohydrate, 0 grams of fiber, and 1 gram of protein.The pH of the stomach is extremely acidic (~ pH 2). If you ate a Yummie cake, what do you think would happen to the protein that you ingested as it passes through the stomach? The protein would form longer proteins via dehydration reactions. The protein would become denatured due to the acidic environment. The protein would speed up digestion because it is an enzyme. The protein would get broken down via dehydration reactions.

The protein would become denatured due to the acidic environment.

G2 phase

The second growth phase of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

Within one chromosome, what is the relationship between the sequence of bases in DNA of one sister chromatid compared to the other?

The sequences are identical.

S phase

The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.

Taq polymerase is an enzyme isolated from the organism Thermus aquaticus. This organism has been found living in the hot springs of Yellowstone National Park. This enzyme is used to copy human DNA from crime scenes. Most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme?

The temperature should be raised.

For each molecule of glucose that enters glycolysis, two molecules of pyruvate are produced.

These are oxidized, and then two molecules of acetyl CoA are ready to enter the citric acid cycle.

What do the rough endoplasmic reticulum, Golgi apparatus, and lysosomes have in common?

They are constructed of interrelated membranes.

How do cells capture the energy released by cellular respiration?

They produce ATP.

A pesticide kills 95% of a pest population. What will be the result of the continued application of this pesticide? The pest population will reach an equilibrium point at which the pesticide is 50% effective. Through time, the pesticide will become less effective at killing the pest. The pesticide will become resistant to the pest. Every time the pesticide is applied, it will kill 95% of the pest population.

Through time, the pesticide will become less effective at killing the pest.

Which of the following statements regarding triglyceride molecules is false? Triglycerides are a type of fat. Triglycerides consist of three fatty acids attached to a glycerol molecule. Triglycerides are hydrophilic. Triglycerides play a role in energy storage.

Triglycerides are hydrophilic.

In comparing a frog cell in metaphase of mitosis with one in metaphase I of meiosis, how would tell you which was which?

Unlike mitosis, in meiosis each chromosome would be opposite its homolog.

In the lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell." The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur?

Water will leave the balloon.

Through respiration, humans breathe in O2 and breathe out CO2. However, what would happen if we did not breathe in O2?

We would not make enough ATP to meet our energy requirements

In which cell would you find the most lysosomes?

White blood cell that "eats" (phagocytoses) bacteria

While walking at 3 mph, how far would you have to travel to "burn off" the equivalent of an extra slice of pizza, which has about 475 kcal? How long would that take?

You would have to walk about 6 miles, which would take you about 2 hours. (Now you understand why the most effective exercise for losing weight is pushing away from the table!)

Which meal is high in fiber, low in saturated fats, and high in unsaturated fats? a plate of scrambled eggs with a side of cottage cheese a black bean, cheese, lettuce, and sour cream burrito in a flour tortilla a bowl of spaghetti tossed with olive oil, artichokes, and broccoli a rib eye steak, mashed potatoes, and side salad with ranch dressing

a bowl of spaghetti tossed with olive oil, artichokes, and broccoli

A pair of sex chromosomes found in a human male is most like

a bride and groom.

Below is a molecule of caffeine. Which of the following features are not present in a molecule of caffeine? a methyl group one or more double bonds a carboxyl group a carbonyl group

a carboxyl group

Which of the following shows the greatest promise as a cancer chemotherapy agent?

a drug that prevents mitotic spindle from forming

A scientist wants to examine living cells lining the respiratory tract to determine how the cells use tiny hairs to move dirt and mucus away from the lungs. Which of the following instruments would be best, and why?

a light microscope, because it allows observations of whole, live cells

The function of coenzyme A in the citric acid cycle is like

a limousine driver dropping off a couple at the school prom.

The function of coenzyme A in the citric acid cycle is most like

a limousine driver dropping off a couple at the school prom.

A glucose molecule is to starch as _____. a steroid is to a lipid a protein is to an amino acid a nucleic acid is to a polypeptide a nucleotide is to a nucleic acid

a nucleotide is to a nucleic acid

In a hydrolysis reaction, __________. In this process, water is __________. a polymer breaks up to form monomers ... produced monomers are assembled to produce a polymer ... consumed a polymer breaks up to form monomers ... consumed monomers are assembled to produce a polymer ... produced

a polymer breaks up to form monomers ... consumed

A hypothesis is the same as a theory. an explanatory idea that is broad in scope and supported by a large body of evidence. a proposed explanation for a set of observations. a widely accepted idea about a phenomenon.

a proposed explanation for a set of observations.

With the exception of identical twins, siblings who have the same two biological parents are likely to look similar, but not identical, to each other because they have

a similar but not identical combination of genes.

siblings who have the same two biological parents are likely to look similar, but not identical, to each other because they have

a similar but not identical combination of genes.

The endosymbiosis hypothesis proposes that

a small cell lived inside a larger cell to the benefit of both cells.

As of 2010, there are 118 known elements. Of those, how many are believed to be essential to human biology? 11 all of them about 92 about 25

about 25

During cellular respiration, O2 is reduced when it

accepts electrons and forms water

Substrates bind to an enzyme's ________ site.

active

The concentration of K+ ions outside a cell is much lower than it is inside a cell. Which of these mechanisms could the cell use to take large numbers of K+ ions INTO itself from its environment?

active transport

Which of the following processes produces the most ATP per molecule of glucose oxidized?

aerobic respiration

In yeast cells,

alcohol is produced after glycolysis.

Which of these is an example of a population? all of the grasses on a prairie a desert all of the red oak trees in a forest liver

all of the red oak trees in a forest

All living things: utilize energy reproduce store genetic information in DNA molecules are complex and organized all of these

all of these

Contractile; give cell its basic shape; help to cause muscle cell contraction and also allow cells to crawl ('amoeboid movement')

all of these

A carbohydrate:

all of these glucose starch glycogen cellulose

The membranous compartmentalization of a cell

allows different chemical conditions to be maintained in different parts of the cell. Submit

The primary structure of a protein is like the arrangement of beads on a string. In this analogy, the beads are _____. amino acids nucleosides nucleotide bases codons

amino acids

All sexual life cycles involve

an alternation of diploid and haploid stages.

A typical soda contains sugar, flavorings, coloring agents, and carbon dioxide that have been dissolved in water. Soda is therefore _____. a solute a molecule a solvent an aqueous solution

an aqueous solution

Cellular respiration is an example of __________.

an exergonic process

Haploid

an organism or cell having only one complete set of chromosomes

Skin cells are fastened into strong sheets by

anchoring junctions. Submit

Atoms with the same number of protons but with different electrical charges _____. are different isotopes have different atomic masses have different atomic numbers are different ions have different numbers of neutrons

are different ions

In many organisms, including humans, chromosomes are found in homologous pairs. Homologous chromosomes _____.

are identical in the arrangement of their genes, but some versions of the genes may differ between the chromosomes

Mature human nerve cells and muscle cells

are permanently in a state of nondivision

Mature human nerve cells and muscle cells

are permanently in a state of nondivision.

Part complete Sodium chloride (NaCl) dissolves in water because water molecules _____. have a high specific heat have a pH near 7 are polar lose electrons

are polar

Carbohydrates are mainly used in our bodies _____. as structural molecules, such as hair and fingernails for membrane construction as fuel for building genetic material

as fuel

The creation of genetically identical offspring by a single parent, without the participation of sperm and egg, is called

asexual reproduction.

Which of the following consists of prokaryotic cells?

bacteria

Prokaryotes reproduce by

binary fission

Found in plant cells

both

Mitochondria are found in _____.

both plant cells and animal cells

Occurs in sexually mature humans

both processes

A material that resists a change in pH is called a(n) _____. buffer solute acid solvent

buffer

Radioactive isotopes do not occur naturally. are frequently added to foods as nutritional supplements. can be used in conjunction with PET scans to diagnose diseases. are never incorporated into organic compounds.

can be used in conjunction with PET scans to diagnose diseases.

Asexual and sexual reproduction differ in that sexual reproduction _____.

can produce great variation among the offspring

Karyotyping

can reveal alterations in chromosome number. Submit

In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive oxygen. The mice were closely monitored, and in a few minutes, radioactive oxygen atoms showed up in __________.

carbon dioxide

At which level of interaction does life first appear? organism cell organelle tissue

cell

Which of the following occurs during interphase?

cell growth and duplication of the chromosomes

Tissues are composed of _____. cells organs organ systems ecosystems

cells

Cannot be digested by animals:

cellulose

Which of the following lists contains only polysaccharides? cellulose, starch, and glycogen fructose, cellulose, and glucose starch, amino acids, and glycogen sucrose, starch, and cellulose

cellulose, starch, and glycogen

Heating inactivates enzymes by

changing the enzyme's three-dimensional shape.

Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing

chemical energy into kinetic energy.

Photosynthesis happens in:

chloroplasts

Photosynthesis occurs in __________________, and cellular respiration occurs in ______________.

chloroplasts, mitochondria

Meiosis Prophase 1

chromatin condenses into chromosomes, spindle apparatus forms, nucleoli and nuclear membrane disappear; homologous chromosomes (one from mom and one from dad) come together and intertwine (synapsis); where crossing over occurs

Autosome

chromosome that is not a sex chromosome

Cilia differ from flagella in that

cilia are typically more numerous and shorter than flagella.

Arsenic is a poison that binds to a molecule needed to build acetyl CoA. Based on this information, which part of cellular respiration would be stopped if arsenic were ingested?

citric acid cycle

Produces NADH molecules as by-products (via redox reactions):

citric acid cycle glycolysis more than one but not all of these all of these pyruvate oxidation

Enzymes catalyze this pathway's reaction(s):

citric acid cycle pyruvate oxidation more than one but not all of these glycolysis all of these

2nd stage of cellular respiration

citric acid cycle takes place within the mitochondria, oxidation begins with pyrute materials, producing Acetyl-CoA then into the Kreb Cycle, only in eukaryotes

During the G2 phase, the cell

completes preparations for cell division

Two garden plots were planted with corn. The soil was similar in each, and equal amounts of water were applied to each plot. One plot was fertilized, the other was not. The experimenters measured the yield as bushels of corn from each plot. The plot that did not receive the fertilizer was the _____. control plot experimental plot controlled variable dependent variable

control plot

The function of the chloroplast is to _____.

convert light energy to chemical energy

A trace element (present only in very tiny amounts in living things):

copper (Cu)

What type of bond is joining the two hydrogen atoms? ionic hydrophilic hydrophobic hydrogen covalent

covalent

The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called

cytokinesis.

During cytokinesis

cytoplasm is divided into separate cells

During cellular respiration, NADH

delivers its electron load to the first electron carrier molecule.

A DNA nucleotide is composed of a __________. ribose sugar, which is bonded to both a phosphate group and a nitrogenous base ribose sugar, which is attached to a phosphate group, which is bonded to a nitrogenous base deoxyribose sugar, which is bonded to a phosphate group and a nitrogenous base deoxyribose sugar, which is attached to a phosphate group, which is bonded to a nitrogenous base

deoxyribose sugar, which is bonded to a phosphate group and a nitrogenous base

As a scientist employed by the FDA, you've been asked to sit on a panel to evaluate a pharmaceutical company's application for approval of a new weight loss drug called Fat Away. The company has submitted a report summarizing the results of their animal and human testing. In the report, it was noted that Fat Away works by affecting the electron transport chain. It decreases the synthesis of ATP by making the mitochondrial membrane permeable to H+, which allows H+ to leak from the intermembrane space to the mitochondrial matrix. This effect leads to weight loss.Fat Away prevents ATP from being made by

destroying the H+ gradient that allows ATP synthase to work. Submit

Science itself is capable of _____. determining the physical causes for physical phenomena explaining unnatural events formulating untestable hypotheses addressing questions of ethical dilemmas

determining the physical causes for physical phenomena

The movement of atoms, ions, or molecules from a region of higher concentration to regions of lower concentration is called _____.

diffusion

What is an acid? An acid _____. contains hydrogen donates hydrogen ions to solutions is a versatile solvent removes hydrogen ions from solutions

donates hydrogen ions to solutions

DNA has the appearance of a _____. single strand letter U double helix triple helix circle

double helix

Chromatids form _____.

during the S phase

Which of the following has the smallest mass? neutron electron atom proton

electron

An atom and an ion of the same element differ in the number of _____. either protons or electrons protons neutrons electrons

electrons

Most animal cells are

embedded in an extracellular matrix.

The phosphorylation of ADP to form ATP is an _____ reaction that _____ energy.

endergonic ... requires an input of

An immune system cell called the plasma cell produces thousands of antibodies per second for release into the body. What type of intracellular structure would you expect to be very prominent within the cell?

endoplasmic reticulum

kinetic energy

energy of motion

An increase in antibiotic-resistant tuberculosis bacteria is proving to be a problem in treating this disease. This could be due to __________. invention procreation lack of medicine evolution

evolution

A small group of 25 predatory birds populates an island. By chance, three members of the population have superior sight, which gives these birds a significant advantage in capturing prey. After hundreds of generations, the population on the island has risen to 1,500 and all of the birds have superior sight compared to the same species on other islands. This is an example of _____.

evolutionary adaptation

When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will

exhibit a net movement to the side with lower free water concentration.

A white blood cell uses _____ to secrete antibodies (protein molecules) out of itself into the blood surrounding it.

exocytosis

Certain cells that line the stomach synthesize a digestive enzyme and secrete it into the stomach. This enzyme is a protein. Which of the following processes could be responsible for its secretion?

exocytosis

The concentration of Na+ ions outside a cell is higher than it is inside a cell. Which of these mechanisms could the cell use to allow large numbers of Na+ ions to move into it from the surrounding environment?

facilitated diffusion

"Resolution" can be defined as how large the microscope causes the image to appear.

false

An enzyme molecule that works well in a pH 8 evironment will work just as well in a pH 2 environment.

false

Cellular respiration is the major endergonic process occurring in an animal cell.

false

The light microscope can be used to see viruses that are smaller than 0.2 μm/200 nm.

false

Through the energy transformations of cellular respiration, all of the energy in a glucose molecule can wind up in the bonds of ATP molecules. (hint: Second Law of Thermodynamics)

false

If you consume 1 g of each of the following, which will yield the most ATP?

fat

Zygote

fertilized egg

Glycolysis

first step in releasing the energy of glucose, in which a molecule of glucose is broken into two molecules of pyruvic acid

Humans use the calories they obtain from ________ as their source of energy.

food

When considering the formation of membranes, they __________.

form spontaneously in aqueous environments

Meiosis starts with a single diploid cell and produces

four haploid cells.

Large proteins, like DNA polymerase and hemoglobin, are often composed of several polypeptides that are linked together. The _____ level of protein structure describes how the polypeptides are joined to create a larger complex. first second third fourth

fourth

reduction

gain of electrons

Dye molecules injected into a cell might be able to enter an adjacent (neighboring) cell through a:

gap junction

It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that would best facilitate this are

gap junctions.

When a cell uses fatty acids for aerobic respiration, it first hydrolyzes fats to

glycerol and fatty acids. Submit

1st stage of cellular respiration

glycolysis coupled reactions to make ATP takes place in the cells cytoplasm

Which of the following options lists the stages in cellular respiration in the correct order?

glycolysis, the citric acid cycle, and oxidative phosphorylation

Of the three main stages of cellular respiration, which one does not take place in the mitochondria?

glycolysis-- in cytosol

Most of an animal cell's ATP molecules are made inside organelle: __________

At the conclusion of meiosis I, the daughter cells are _____.

haploid and the sister chromatids are joined

During prophase I of meiosis,

homologous chromosomes stick together in pairs.

Two chromosomes in a nucleus that carry genes controlling the same inherited characteristics are

homologous chromosomes.

Meiosis Metaphase 1

homologous pairs align on equator; each pair attaches to separate spindle fiber by its kinetochore

Meiosis Anaphase 1

homologous pairs separate and are pulled to opposite poles of cell; this is called disjunction when they are pulled apart; daughter cells get a mixture of mom and dads chromosomes

A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to treat people with bacterial infections. However, he can't do this because _____.

human cells also perform glycolysis; the drug might also poison them

To obtain energy from starch and glycogen, the body must begin by

hydrolyzing both starch and glycogen to glucose.

The oil and vinegar in your salad dressing remain separate from one another due to the _____ properties of the oil. hydrophobic saturated hydrophilic hydrogenated

hydrophilic

Which is the correct term for compounds that do not mix with water? hydrophobic protein hydrophilic phospholipids

hydrophobic

A scientist notes that an ornamental grass grown in a creek bed is taller than the same type of grass grown on a berm. The scientist suspects that this difference is due to water availability. This proposed explanation is a(n) __________. observation question prediction hypothesis

hypothesis

Where does glycolysis occur in a eukaryotic cell?

in the cytoplasmic fluid

Meiosis only occurs

in the ovaries and testes (gametes)

Lipid molecules:

include triglycerides and steroids

Cable-like fibers that form a strong 3-D meshwork; many large organelles (like nucleus and ER) are attached to them; they attach to anchoring junctions

intermediate filaments

Part of the cytoskeleton

intermediate filaments none of these microfilaments microtubules all of these

A cell preparing to undergo meiosis duplicates its chromosomes during

interphase

Both mitosis and meiosis are preceded by

interphase

Eukaryotic cells spend most of their cell cycle in which phase?

interphase

A cell preparing to undergo meiosis duplicates its chromosomes during

interphase.

As pyruvate is produced at the end of glycolysis, it is transported from the cytosol, where glycolysis takes place...

into a mitochondrion, where the citric acid cycle and oxidative phosphorylation will occur.

Medicines are often administered in pill form. In many cases, the active ingredient of the pill (the drug) is joined to another substance by ________. This forms a(n) ________, which is stable in the dry environment of a pill bottle but dissociates under the wet conditions of the digestive system to release the drug to the body. ionic bonds; acid ionic bonds; salt hydrogen bonds; base covalent bonds; salt

ionic bonds; salt

_______ bonds are found between the oppositely charged particles in a salt crystal; _______ bonds are found between the C,H, and O atoms in sugar molecules; _______ bonds help stabilize the coils and folds of DNA and protein molecules. covalent, ionic, hydrogen ionic, Hydrogen, covalent ionic, covalent, Hydrogen Hydrogen, ionic, covalent Hydrogen, covalent, ionic

ionic, covalent, Hydrogen

A valid hypothesis:

is based on logic, common sense, and previous experience. allows you to make predictions. is an answer to a question. can be tested. all of these

Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment

is hypotonic to the protozoan.

Researchers testing new drugs usually give the drug to one group of people and give placebos ("sugar pills") to another group. The group receiving the sugar pills:

is the control group

A cell that has neither a net gain of water nor net loss of water when it is immersed in a solution must be

isotonic to its environment.

Which of these gives a protein molecule its function?

its 3-dimensional shape

The maximum size of a cell is limited by _____.

its need for enough surface area to make exchanges with its environment

Sister chromatids are

joined together at a centromere.

Sister chromatids are

joined together at a centromere. Submit

Sister chromtids are

joined together by centromere

Light is _____ energy, which is converted into _____ energy by plants.

kinetic ... chemical

When a car engine burns gasoline, the results of the reaction are similar to when cells burn glucose. Both reactions release carbon dioxide and water. In cells, the chemical energy in food is converted to ATP and heat. In a moving car, the chemical energy in gasoline is converted to

kinetic energy and heat

Kinetic energy differs from chemical energy in that

kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.

Dehydration reactions __________. They do so by __________. link monomers to form a polymer; adding a water molecule link monomers to form a polymer; removing a water molecule remove monomers from polymers; removing a water molecule remove monomers from polymers; adding a water molecule

link monomers to form a polymer; removing a water molecule

Cholesterol belongs to which class of molecules? proteins carbohydrates lipids amino acids

lipids

In cellular respiration, glucose _____ electrons, whereas _____ electrons.

loses ... oxygen gains

A molecule that functions as the electron donor in a redox reaction __________.

loses electrons and becomes oxidized

Oxidation

loss of electrons

Adding a base tends to _____ of a solution. lower hydrogen ion concentration and lower the pH increase hydrogen ion concentration and lower the pH increase the hydrogen ion concentration and increase the pH lower hydrogen ion concentration and increase the pH

lower hydrogen ion concentration and increase the pH

If the nucleus is the cell's "control center", and chloroplasts are its "solar collectors", which of the following might be the cell's combination "food processor" and "garbage disposal"?

lysosome

The cells of a person with adrenoleukodystrophy (ALD) swell with a buildup of fatty acids. In other words, fatty acids are not being broken down. Which organelle is most likely failing to function correctly?

lysosome

Tay-Sachs disease results from the malfunction of

lysosomes

A diploid cell produces 4 genetically nonidentical haploid cells

meiosis

Crossing over occurs between homologous chromosomes

meiosis

Homologous chromosomes pair together

meiosis

Meiosis 2: Telophase 2 and Cytokinesis

meiosis 2 results in 4 haploid daughter cells

What is the stage of cell division in a diploid organism if you see seven chromosomes, each consisting of a pair of sister chromatids?

meiosis II prophase Submit

Nondisjunction occurs when

members of a chromosome pair fail to separate.

During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles?

metaphase

The protein actin is a component of a(n) __________.

microfilament

Lysosomes and transport vesicles get towed along these by "walking" motor proteins

microtubules

Which of the following cytoplasmic structures functions in the transport of vesicles from the endoplasmic reticulum to the Golgi apparatus?

microtubules

Made of protein molecules

microtubules microfilaments none of these intermediate filaments all of these

The internal skeleton of a cell is composed of _____.

microtubules, intermediate filaments, and microfilaments

Cellular respiration happens inside:

mitochondria

Found in animal cells

mitochondria

In Eukaryotes, where can the electron transport chain be found?

mitochondria

The electron transport chain is a series of electron carrier molecules. In eukaryotes, where can this structure be found?

mitochondria

The endosymbiosis hypothesis is supported by all of the following pieces of evidence except the fact that

mitochondria lack ribosomes like prokaryotes.

A scientist wants to study the enzymes of the citric acid cycle in eukaryotic cells. What part of the cell would she use as a source of these enzymes?

mitochondrial matrix

Where are enzymes of the citric acid cycle in eukaryotic cells located?

mitochondrial matrix

The enzymes of the citric acid cycle are located in the

mitochondrial matrix.

A diploid cell produces 2 genetically identical diploid daughter cells

mitosis

After fertilization, the resulting zygote begins to divide by _____.

mitosis

__________ heals wounds, causes body growth and replaces dead somatic cells

mitosis

Some friends are trying to make wine in their basement. They've added yeast to a sweet grape juice mixture and have allowed the yeast to grow. After several days they find that sugar levels in the grape juice have dropped, but there's no alcohol in the mixture. The most likely explanation is that the

mixture needs less oxygen because yeasts only produce alcohol in the absence of oxygen.

A(n) _____ refers to two or more atoms held together by covalent bonds. molecule shell community ion isotope

molecule

monosaccharides

Produces CO2 molecules as by-products:

more than one but not all of these

Cell is put into a 100% water environment Assuming that the fluid inside the cell has a solute concentration of 5%; what will happen?

more water molecules will enter the cell than leave it, cell will swell Submit

Cell is put into a 10% solute environment. Assume that the fluid inside the cell has a solute concentration of 5%. What will happen?

more water molecules will leave the cell than enter it, cell will shrivel

What happens to a cell in a hypertonic environment?

more water molecules will leave the cell than enter it, cell will shrivel

Cellulose differs from starch in that most animals cannot break down cellulose, whereas starch is easily digested. starch is formed by plants and cellulose by animals. starch is made of glucose monomers, whereas cellulose is made of fructose monomers. cellulose is highly branched, whereas starch is unbranched.

most animals cannot break down cellulose, whereas starch is easily digested.

Bacteria have:

neither

A solution with a pH of 7 is neutral. strongly acidic. weakly acidic. weakly basic.

neutral.

You're on the pilot episode of a new reality show called "The Transport Factor." The host hands you three different amino acids, four different sugars, and two different ions. Then the host shouts, "How many different proteins does the cell need to move these molecules across the plasma membrane using facilitated transport?" Quickly, you correctly respond: _____.

nine

Which four elements are the primary components of important biological molecules, such as proteins, fats, and carbohydrates? calcium, nitrogen, carbon, and oxygen sodium, hydrogen, carbon, and oxygen nitrogen, carbon, hydrogen, and oxygen oxygen, carbon, hydrogen, and water

nitrogen, carbon, hydrogen, and oxygen

The synthesis of an amino acid follows this pathway: precursor A → intermediate B → amino acid C. Each reaction is catalyzed by a different enzyme. This metabolic pathway is controlled by feedback inhibition with amino acid C inhibiting the conversion of precursor A to intermediate B. Amino acid C acts as a _____ of the first enzyme in the pathway.

noncompetitive inhibitor Submit

If the four cells shown resulted from cell division of a single cell with diploid chromosome number 2n = 4, what best describes what just occurred?

nondisjunction

DNA is composed of building blocks called _____. nucleicacids Gs nucleotides adenines amino acids

nucleotides

Most of the DNA in a eukaryotic cell is in the _____.

nucleus

The __________ determines a particular atom's identity

number of protons it has

A hydrogen atom has one electron. How many covalent bonds can hydrogen form? two none four one

one

The pairing up of homologous chromosomes and crossing over ...

only occur during meiosis

If you eat a hamburger, you are mainly eating ground-up beef muscle. What levels of organization are represented in this ground-up muscle? organism, population, and community organelle, cell, and tissue organ, organ system, and organism tissue, organ, and organ system

organelle, cell, and tissue

The diffusion of water across a selectively permeable membrane is called __________.

osmosis

Because an electron transfer requires both a donor and an acceptor...

oxidation and reduction always go together.

3rd stage of cellular respiration

oxidative phosphorylation

In the electron transport chain, the final electron acceptor is

oxygen

The plasma membrane is selectively permeable. Which of the following can pass freely through the membrane with no assistance?

oxygen and carbon dioxide

Oxygen crosses a plasma membrane by

passive transport.

The transfer of a phosphate group to a molecule or compound is called

phosphorylation.

Chloroplasts are found in __________.

plant cells and some protists

Foods that are high in fiber are most likely derived from dairy products. plants. fish. red meats.

plants.

Cellulose is a _____ made of many _____. polypeptide ... monomers carbohydrate ... fatty acids polymer ... glucose molecules protein ... amino acids

polymer ... glucose molecules

DNA carries the instructions for building _____, and these instructions are found in informational units called _____. carbohydrates ... libraries lipids ... libraries polypeptides ... genes steroids ... genes

polypeptides ... genes

Muscle cells use ATP generated by cellular respiration to

power contractions

Another name for a protein molecule's amino acid sequence:

primary structure

Not changed when a protein molecule is denatured:

primary structure

A protein containing more than one polypeptide chain exhibits the ________ level of protein structure. primary structure primary and secondary structure primary, secondary, and tertiary structure primary, secondary, tertiary, and quaternary structure

primary, secondary, tertiary, and quaternary structure

In telophase of mitosis, the mitotic spindle breaks down and nuclear membranes form. This is essentially the opposite of what happens in:

prophase

The phase of mitosis during which the mitotic spindle begins to form is

prophase

Many cancer drugs known as "antimitotics" target microtubules. What is the first stage of mitosis at which these drugs are likely to have an effect?

prophase Submit

The correct order of events during meiosis is

prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis II.

During meiosis, segments of nonsister chromatids can trade places. This recombination of maternal and paternal genetic material is a key feature of meiosis. During what phase of meiosis does recombination occur?

prophase I.

During what phase of meiosis does recombination occur?

prophase I.

The phase of mitosis during which the mitotic spindle begins to form is

prophase.

The phase of mitosis during which the mitotic spindle begins to form is

prophase. Submit

Most of the functions of a cell membrane, including transport and enzymatic function, are performed by

proteins

Most of a cell's enzymes are

proteins.

The role of a control in an experiment is to provide a basis of comparison to the experimental group. prove that a hypothesis is correct. counteract the negative effect of the experiment. ensure repeatability.

provide a basis of comparison to the experimental group.

In oxidative phosphorylation, electrons are passed from one electron carrier to another. The energy released is used to _____.

pump protons (H+) across the mitochondrial membrane

Part complete In oxidative phosphorylation, electrons are passed from one electron carrier to another. The energy released is used to _____.

pump protons (H+) across the mitochondrial membrane

After glycolysis but before the citric acid cycle,

pyruvate is oxidized

After glycolysis but before the citric acid cycle,

pyruvate is oxidized. Submit

The by-products of the citric acid cycle include all of the following except

pyruvate.

A characteristic of protein molecules like hemoglobin, which contain more than one polypeptide chain:

quaternary structure

Fermentation is essentially glycolysis plus one more reaction in which the pyruvate molecule is reduced to form a lactate molecule (i.e., lactic acid) or alcohol and CO2 This last step:

reoxidizes NADH molecules into NAD+ molecules

There are a number of properties that all organisms share. In humans, exposure to ultraviolet light can result in a darkening of the skin. What kind of property is this? growth and development response to the environment energy processing regulation

response to the environment

Anything that prevents ATP formation will most likely

result in cell death.

Much of the intracellular structure of a eukaryote cell is involved in protein synthesis. The figure shows the amounts of protein in cells at different parts of the cell cycle between two cell divisions. G1 is a stage just after the cell has divided, and G2 is the stage just before the cell divides again. S is a stage when the cell is synthesizing material such as DNA, mitochondria, and other organelles.Most of the protein measured in the cells was likely synthesized by

ribosomes

Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. Which of the following options correctly lists the order of the structures through which insulin passes from its production to its exit from the cell?

rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane

The cells that produce hair made of protein contain a lot of ________, while the cells that produce the oils that coat the hair contain a lot of ________.

rough endoplasmic reticulum; smooth endoplasmic reticulum

The architecture of cell surfaces can be viewed in the most detail using a __________.

scanning electron microscope

A protein molecule's __________ is caused by Hydrogen bonding; alpha-helix and beta-pleated sheet are examples

secondary structure

You would expect a cell with an extensive Golgi apparatus to _____.

secrete a lot of material

Gametes

sex cells

Your body contains thousands of different types of proteins, each with a specific function. A protein's function is largely determined by its _____. shape electrical charge size elemental composition

shape

Cleopatra tried a new cold medicine called SniffleSnuffer on her children. She said, "My seven kids got lots of coIds last winter. This year, I gave them all SniffleSnuffer, and none of them got colds. SniffleSnuffer is certainly an effective cold preventer!" Cleopatra's experiment is not very good...how could it be improved?

she should give some of her kids SniffleSnuffer, and some should get none

Independent orientation of chromosomes at metaphase I and random fertilization are most like

shuffling cards and dealing out hands of poker.

Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called

sister chromatids

In meiosis II, _____.

sister chromatids are separated

Prior to mitosis and after S phase, each chromosome of a eukaryotic cell consists of a pair of identical structures called

sister chromatids.

Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called

sister chromatids.

The skin is the body's largest organ. It's made up of many different types of cells. Oils, produced by the sebaceous glands, prevent the skin from drying and splitting. The protein melanin, produced by melanocytes in the epidermis, protects the skin from the harmful effects of ultraviolet radiation. Sweat, released through ducts to the skin surface, helps to cool the body. The types of cells that produce these compounds have different numbers of specific organelles, depending on their function.The oil from the sebaceous glands is produced by which of the following cell organelles?

smooth endoplasmic reticulum

The lipids in a cell membrane are arranged _____.

so that the nonpolar parts of two lipids point toward each other

When you eat a plant, you derive energy from the stored __________, but not from the __________ component. cellulose ... chitin starch ... chitin glycogen ... cellulose starch ... cellulose

starch ... cellulose

High-fructose corn syrup is made from corn. The main carbohydrate in corn is a polysaccharide called cellulose. hydrocarbon. starch. fructose.

starch.

Which of the following substances is made of lipids? DNA steroids enzymes cellulose

steroids

potential energy

stored energy

The Golgi apparatus

stores, modifies, and packages proteins.

glycolysis and citric acid cycle

supply the electrons needed for the electron transport chain

During which phase of mitosis does the nuclear envelope re-form?

telophase

During which phase of mitosis does the nuclear envelope re-form?

telophase Submit

A liter of soda, at pH 3, contains ____ H+ as a liter of coffee, at pH 4.

ten times as many

Grapefruit juice is approximately pH 3, and tomato juice is approximately pH 4. A glass of grapefruit juice contains _____ H+ as a glass of tomato juice. ten times as much twice as much one-tenth as much half as much

ten times as much

To be of value to science, hypotheses must be __________. testable established facts proven correct popular

testable

A company was testing a new drug they thought would help decrease the risk of transmitting viruses from mother to fetus. In an experiment to test the compound, a worker gave 400 pregnant female rats a small dose of the experimental drug and inoculated each with a type of virus known to cause disease in rats. An additional 400 pregnant rats were given only the virus. Of the rat pups born to the females that received both the virus and the drug, 203 showed no symptoms of the disease; 207 rat pups born to virus-only females showed symptoms. From this test, we can best conclude _____. nothing, because no independent variable could be identified that the drug seems to have little effect on viral transmission at the dosage given that the drug is 2% effective and testing on humans should begin nothing, because no control group was used in the test of the drug

that the drug seems to have little effect on viral transmission at the dosage given

A Chlorine atom (Cl, atomic number=17) takes an electron from a nearby Sodium atom (Na, atomic number =11). When this happens, then the Na atom becomes a positive ion a peptide bond forms between the two atoms the Na atom becomes a negative ion a covalent bond forms between the two atoms a Hydrogen bond forms between the two atoms

the Na atom becomes a positive ion

The genetic material is duplicated during

the S phase.

The primary structure of a protein is composed of two or more polypeptide chains .the amino acid sequence of the polypeptide chain. an alpha helix or a pleated sheet. maintained by hydrogen bonds.

the amino acid sequence of the polypeptide chain.

basal metabolic rate

the body's resting rate of energy expenditure

Amino acids can be distinguished from one another by the chemical properties of their R groups. the number of R groups found on the amino acid molecules. the chemical properties of their amino and carboxyl groups. the type of bond between the R group and the rest of the amino acid molecule.

the chemical properties of their R groups.

Most NADH molecules generated during cellular respiration are produced during __________.

the citric acid cycle

acetyl CoA is produced during

the citric acid title

The term resolving power refers to _____.

the clarity of the image in showing two objects as separate

The transport of molecules of a particular solute from inside an animal cell across the cell membrane to the extracellular fluid always requires energy when _____.

the concentration of the solute is lower inside the cell than outside it

Human liver cells contain an enzyme called alcohol dehydrogenase (ADH), which catalyzes this reaction: Alcohol Dehydrogenase (ADH) Ethanol --------------------------------------------------------> acetaldehyde According to the 'induced fit' model of enzyme activity:

the ethanol molecule is shaped not at all like ADH's active site

According to ________, energy cannot be created or destroyed.

the first law of thermodynamics

A scientist suspects that the food in an ecosystem may have been contaminated with radioactive nitrogen over a period of months. Which of the following substances could be examined for radioactivity to test the hypothesis? the hair produced by humans living in the ecosystem the sugars produced during photosynthesis by plants growing in the ecosystem the cell walls of plants growing in the ecosystem the cholesterol in the cell membranes of organisms living in the ecosystem

the hair produced by humans living in the ecosystem

When you add acid to a solution, _____. the hydrogen ion concentration increases and lowers the pH the hydrogen ion concentration increases and raises the pH the hydrogen ion concentration decreases and raises the pH the hydrogen ion concentration decreases and lowers the pH

the hydrogen ion concentration increases and lowers the pH

The mitotic phase is

the interval of the cell cycle when the cell physically divides. divided into two overlapping stages, called mitosis and cytokinesis

If a cell is like a factory, then enzyme molecules are like:

the machines in the factory

the mixture needs less oxygen because yeast only produce alcohol in the absence of oxygen.

The enzyme ATP synthase catalyzes the phosphorylation of ADP to form ATP. In eukaryotic cells, the energy needed for this endergonic reaction is derived from _____.

the movement of hydrogen ions across the mitochondrial membrane

Where does the enzyme ATP synthase find the energy to catalyze the phosphorylation of ADP to form ATP.

the movement of hydrogen ions across the mitochondrial membrane

A drug that interferes with microtubule formation is likely to completely disrupt

the movements of sperm cells.

Which of the following characteristics of protein will remain intact if the protein is denatured? the shape of the protein the binding properties of the protein the function of the protein the number of amino acids in the protein

the number of amino acids in the protein

Generally, what determines the number and kinds of chemical bonds an element can make and the chemical reactivity of an element? number of protons plus the number of neutrons number of electron shells present in the atoms the number of electrons in its outer shell mean energy level of its electrons

the number of electrons in its outer shell

How an atom will react and form bonds with other atoms is determined by: the number of protons it has the number of electrons in its outermost electron shell the number of neutrons it has the total number of electrons it has

the number of electrons in its outermost electron shell

The tertiary structure of a polypeptide refers to its size. the presence of pleated sheets .the amino acids of which it is made. the overall three-dimensional structure.

the overall three-dimensional structure.

To enter or leave any cell, substances must pass through _____.

the plasma membrane

Plasma membranes are selectively permeable. This means that

the plasma membrane allows some substances to enter or leave a cell more easily than others.

In the reaction A → B + C + heat,

the potential energy of the products is less than that of the reactant.

Cellular respiration, or the oxidization of glucose, involves

the release of CO2

A steer must eat at least 100 pounds of grain to gain less than 10 pounds of muscle tissue. This illustrates

the second law of thermodynamics. Submit

Proteins differ from one another because the sequence of amino acids in the polypeptide chain differs from protein to protein. each protein contains its own unique sequence of sugar molecules. the peptide bonds linking amino acids differ from protein to protein. the number of nucleotides found in each protein varies from molecule to molecule.

the sequence of amino acids in the polypeptide chain differs from protein to protein.

Within one chromosome, what is the relationship between the sequence of bases in DNA of one sister chromatid compared to the other?

the sequences are identical

The chemical energy used by most organisms for metabolism and growth ultimately comes from __________. carbon dioxide the sun heat the decomposition of plants

the sun

Which of the following processes is endergonic?

the synthesis of glucose from carbon dioxide and water

You're the manager of a factory that produces enzyme-washed blue jeans (the enzymes lighten the color of the denim, giving a "faded" appearance). When the most recent batch of fabric came out of the enzyme wash, however, the color wasn't light enough to meet your standards. Your quality control laboratory wants to do some tests to determine why the wash enzymes didn't perform as expected.Based on your understanding of enzyme structure, which of the following would you recommend that they also investigate? the temperature of the liquid in the washing vat the primary structure of the enzyme the manufacturer of the fabric how long the fabric has been in storage

the temperature of the liquid in the washing vat

electronegative

the tendency to attract electrons to form a chemical bond

Oxidative phosphorylation could not occur without glycolysis and the citric acid cycle, because _____.

these two stages supply the electrons needed for the electron transport chain Submit

During mitosis, the chromosomes move because _____.

they attach to a dynamic, precisely regulated mitotic spindle

During mitosis, the chromosomes move because _____.

they attach to a dynamic, precisely regulated mitotic spindle It is the extension and shortening of microtubules that are attached to opposite faces of chromosomes that controls chromosome movement.

Rotenone is a poison commonly added to insecticides. Rotenone binds tightly with one of the electron carrier molecules in the electron transport chain, preventing electrons from passing to the next carrier molecule. Insects exposed to rotenone will die because

they will no longer be able to produce adequate amounts of ATP.

A protein's alpha helices and beta sheets fold together to create an overall shape at the _____ level of protein structure. first second third fourth

third

A Nitrogen atom (N, atomic number=7) can covalently bind with several Hydrogen atoms (H, atomic number=1) to form an ammonia molecule. How many Hydrogen atoms are in an ammonia molecule?

three

Phosphorus-32 (radioactive) has _____ than phosphorus-35 (normal). three fewer neutrons three fewer protons three more protons three more neutrons

three fewer neutrons

An antibiotic kills 99.9% of a bacterial population. You would expect the next generation of bacteria to be more contagious than the prior generation. to be just as susceptible to that antibiotic as was the previous generation. to die out due to the drastic decrease in population size. to be more resistant to that antibiotic.

to be more resistant to that antibiotic.

Strontium atoms, when injected into the bloodstream, tend to be taken up by healthy bone cells and incorporated into bone tissue. Thus, what would be the most likely medical use for radioactive Strontium isotopes?

to make an PET scan image of a bone to determine whether it was diseased

The function of the nucleolus is

to manufacture ribosomal RNA.

If you wished to clearly observe the organelles inside of a white blood cell, which type of microscope would you choose?

tranmission electron microscope

Both facilitated diffusion AND active transport:

transport molecules that can pass directly through the phospholipid bilayer

Gussie noticed that his friend Bertie had put on a little weight recently. "Ah," said Gussie, "storing up some _________ for the winter, I see."

triglycerides

A scanning electron microscope may be used to view cilia on the surface of a cell.

true

ATP molecules activate monomers, ion pump proteins, and motor proteins by adding phosphate groups to them.

true

An enzyme molecule that works best at 37C probably will work, but not as well, at 30C.

true

An enzyme that catalyzes the breakdown of hydrogen peroxide molecules probably won't catalyze the breakdown of ibuprofen molecules too.

true

Because seawater is hypertonic, ocean fish tend to lose water molecules to their environment, and must drink constantly to compensate.

true

Chemical energy is a form of potential energy.

true

Electrical energy can be transformed into mechanical energy.

true

Most living cells are hard to see in the light microscope because they are transparent.

true

Practically every chemical reaction in a cell is catalyzed by an enzyme.

true

The internal structure of a mitochondrion may be seen with a transmission electron microscope.

true

A scientist performs a controlled experiment. This means that the experiment is repeated many times to ensure that the results are accurate. the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data. one experiment is performed, but the scientist controls the variables. two experiments are conducted, one differing from the other by only a single variable.

two experiments are conducted, one differing from the other by only a single variable.

A disaccharide forms when two starches join by dehydration synthesis. two starches join by hydrolysis. two monosaccharides join by dehydration synthesis. two monosaccharides join by hydrolysis.

two monosaccharides join by dehydration synthesis.

Radon is a radioactive gas that seeps into homes from the soil. It is thought to be a leading cause of lung cancer. A research team investigates this theory. They gather large amounts of data on basement radon concentrations and lung cancer rates and conclude that the more radon there is, the more likely lung cancer is. After the study is published, other researchers criticize it by asserting that the studied neighborhoods with higher radon concentrations also have a higher percentage of old people and a higher percentage of cigarette smokers than the low-radon neighborhoods. Both advanced age and cigarette smoking increase the risk of lung cancer. This criticism, if correct, shows that the radon study suffered from _____. uncontrolled variables a lack of replicationan unfalsifiable hypothesis nonsystematic observation

uncontrolled variables

Looking into your microscope, you spot an unusual cell. Instead of the typical rounded cell shape, the cell has a very narrow middle separating two bulging ends. It sort of looks like the number 8! You realize that this cell is

undergoing cytokinesis.

A fatty acid containing at least one double bond is called _____. hydrophilic cholesterol unsaturated saturated

unsaturated

Fatty acids with double bonds between some of their carbons are said to be unsaturated. saturated. monoglycerides. completely hydrogenated.

unsaturated.

What substance is transported by aquaporins?

water

A cell is put in a 5 % solute environment. Assuming that the fluid inside the cell has a solute concentration of 5%. What will happen?

water molecules will enter and leave the cell at the same rate, cell's volume won't change

Lysozyme is an enzyme that breaks down bacterial cell walls and is found in your tears, mucus, and saliva. A mutation occurs in the gene for lysozyme that results in a lysine (a positively charged amino acid) being substituted for an arginine (also a positively charged amino acid). Do you think that the mutant lysozyme will function similarly to the normal lysozyme? no, because changing lysine to arginine will cause the protein to denature yes, because both lysine and arginine are positively charged so the tertiary structure and therefore function should be similar yes, because protein function stays the same no matter what mutations occur no, because all changes in protein primary sequence result in functional differences

yes, because both lysine and arginine are positively charged so the tertiary structure and therefore function should be similar

Which of the following is a trace element in the human body? zinc oxygen hydrogen nitrogen

Biology Unit 3

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