Bio 135 Test 1 (test like questions)

A sodium atom has a mass number of 23. Its atomic number is 11. How many electrons does a neutral sodium atom have?

11

All proteins can be made from varying combinations of ___________amino acids.

20

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

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

8 and 17

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

A hypothesis is a proposed explanation for the observation of the warning light. The actual reason may be different and would only be found through making a prediction and testing that prediction.

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?

A suntan is a response by skin cells to the environment. The suntan protects the body from absorbing an excess of solar radiation.

The purpose of cellular respiration is the production of __________.

ATP

How are cohesion and surface tension related to the chemical properties of water?

All are properties related to hydrogen bonding.

A property of life known as energy processing refers to the fact that living things __________.

All organisms must process energy in order to survive.

What evidence caused scientists to initially (but incorrectly) place red pandas in the same family as giant pandas?

Although this conclusion was later rejected in light of more recent information, the two species were formerly placed into the same family due to these similarities.

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?

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

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 to occur. 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 __________.

An important feature of the scientific process is the controlled experiment in which two groups are established and treated exactly alike, except for the one variable the experiment is designed to test.

A pesticide kills 95% of a pest population. What will be the result of the continued application of this pesticide?

As a result of the application of the pesticide, those individuals that are resistant will have greater reproductive success than individuals that are sensitive to the pesticide.

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?

As in all populations, individuals in human populations vary in their traits. Some individuals have genetic modifications that do not allow entry of HIV into their immune cells, thus making them immune to the virus and its effects. Such individuals could be favored by natural selection.

What do phospholipids and cholesterol have in common?

Both are important components of cell membranes.

Information dictating the primary sequence of a polypeptide is permanently maintained within a cell in which of the following forms?

DNA

What is the molecular commonality that is the basis of life's variety?

DNA

The chemical energy used by most organisms for metabolism and growth ultimately comes from __________.

Energy for life ultimately comes from the energy of the sun, trapped by photosynthetic organisms.

Actinosphenia elegans is a unicellular, photosynthetic, eukaryotic organism. To which domain does it belong?

Eukarya

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?

Hydrogen ions are very reactive, and a person cannot survive a dramatic decrease in pH. Submit

Scientific experimentation is important in that it allows the experimenter to __________.

Hypotheses can be rejected when contradictory evidence emerges.

When water freezes, ice floats. Why?

In ice, the water molecules are farther apart than in liquid water.

What does the term amino acid signify about the structure of the molecule?

It consists of an amino group and a carboxyl group.

At which level of interaction does life first appear?

Life emerges from the ordered interactions of the structure of the cell.

In which of the following kingdoms can most multicellular photosynthetic organisms be found?

Most multicellular eukaryotes that carry out photosynthesis are placed in the kingdom Plantae.

Which of the following statements is true about the chemical nutrients in an ecosystem?

Nutrients cycle through the ecosystem, being returned for availability by processes such as decomposition.

Local farmers think that a commonly used pesticide is responsible for the increase in appearance of frogs with an additional appendage. To test this hypothesis, frogs are injected with a small amount of pesticide mixed in ethanol. The frogs are allowed to produce offspring to test the effect of the pesticide. Which of the following would be the best controlled experiment?

One group is injected with ethanol, one group is injected with pesticide, and one group is not injected with anything. Submit

A single-celled eukaryotic organism that is neither a consumer nor a decomposer would most likely be classified in _____.

Protista is a diverse group of several kingdoms, but some of its members are algae, single-celled producers.

Which of the following groups within the domain Eukarya does NOT represent a single kingdom?

Protists are a group of mainly unicellular eukaryotes that represent several kingdoms. A revised classification of protists is currently underway.

How does DNA differ from RNA?

RNA contains ribose, DNA does not.

what correctly describes bonds of the secondary structure of proteins?

Secondary structure involves hydrogen bonding between atoms of the polypeptide backbone. Submit

What would happen if an ecosystem lacked decomposers?

The ecosystem would stop functioning as nutrients became locked up in dead organic matter.

What is the benefit of the red panda's enlarged radial sesamoid?

The enlarged radial sesamoid acts as a "false thumb," enabling the red panda to grasp objects by pressing one or more of its parallel digits to this "thumb."

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.

An increase in antibiotic-resistant tuberculosis bacteria is proving to be a problem in treating this disease. This could be due to __________.

The individuals with heritable traits best suited to surviving in this antibiotic environment will leave the greatest number of healthy, fertile offspring.

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. Submit

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

What is an essential difference between animal and plant cells that could explain how a plant cell can withstand this expansion of the central vacuole?

The plant cell wall provides a more rigid structure.

Which of the following is a reason why most scientific inquiries fail to rigidly adhere to the sequence of steps typically termed "the scientific method"?

The process of science is both repetitive and nonlinear.

Lactose is a disaccharide (two monosaccharides joined together). To metabolize lactose, individuals require an enzyme known as lactase. What is true about this reaction?

The reaction hydrolyzes the sugar. Submit

The hydrogen bonds in liquid water are less stable than in ice. Why?

There is less movement of molecules in colder conditions.

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

They are constructed of interrelated membranes. Submit

When calorie intake is low, proteins are the last resource the body uses for fuel. Which statement below gives the best reason for this?

When the body uses proteins as fuel, it is breaking down substances vital to its structure and essential functions.

An acid is _____.

a compound that donates hydrogen ions to a solution

A glucose molecule is to starch as __________.

a nucleotide is to a nucleic acid Submit

In a hydrolysis reaction, __________. In this process, water is __________.

a polymer breaks up to form monomers ... consumed Submit

A hydrogen bond is _____.

a weak interaction between two molecules

Proteins are an important class of molecules because of the functions they perform. Proteins can _____.

act as signal receptors to receive signals in cell communication

Which type of cytoskeletal protein is also involved in muscle contractions?

actin

Manufacturers make vegetable oils solid or semisolid by _____.

adding hydrogens

Human proteins, such as insulin, can be produced by bacterial cells. This is possible because __________.

all organisms share a common genetic code Submit

Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they _____.

all share the same functional group, a hydroxyl

A typical soda contains sugar, flavorings, coloring agents, and carbon dioxide that have been dissolved in water. Soda is therefore _____.

an aqueous solution

Carbohydrates are mainly used in our bodies _____.

as fuel

Mitochondria are found in _____.

both plant cells and animal cells

Peroxisomes are organelles that are involved in the _____.

breakdown of fatty acids

Which is a typical function of lysosomes?

breaking down of damaged organelles, such as mitochondria

A material that resists a change in pH is called a(n) _____.

buffer

How do isotopes of an element differ?

by atomic mass number Submit

Which element is closely associated with the field of organic chemistry?

carbon

The function of the chloroplast is to _____.

convert light energy to chemical energy

The reaction that joins two monomers to form a polymer is known as a _____ reaction. The molecule of water formed is due to the interaction between _____ and a hydrogen ion.

dehydration ... a hydroxyl group

A peptide bond is formed through a __________.

dehydration reaction between the amino group of one amino acid and the carboxyl group of a second amino acid

A DNA nucleotide is composed of a __________.

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

Positron-emission tomography (PET) is a technique that doctors may use to _____.

determine hot spots of metabolic activity

Which of the following are stored in the lysosomes of the cell?

digestive enzymes

Cilia and flagella move thanks to the energy provided by __________, a special motor protein that can harvest energy from ATP.

dynein arms

An atom's reactivity is determined by its _____.

electron configuration

An atom and an ion of the same element differ in the number of _____.

electrons

The contractile vacuole __________.

eliminates excess water from the cytoplasm of freshwater protists

Which condition is irrelevant, to some extent, to the maintenance of protein structure in your body?

environmental temperature

The number of protons in an uncharged atom _____.

equals the total number of electrons in the orbital shells

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

What is external to the plasma membrane?

extracellular matrix

Which of the following structures is directly involved in the passage of electrical signals between cells as, for example, in the vertebrate heart?

gap junctions

Mitochondria and chloroplasts are similar in that they both __________; however, they are different in that only chloroplasts, and not mitochondria, __________.

have a double membrane ... carry out photosynthesis

Water can resist temperature change because _____.

heating water absorbs energy by disrupting the hydrogen bonds before evaporation can occur

Which is the correct term for compounds that do not mix with water?

hydrophobic

What changes would you expect to see in the liver cells of someone suffering from chronic alcoholism?

increased levels of endoplasmic reticulum activity

Signals are transmitted between the extracellular matrix to the cytoskeleton through __________ proteins.

integrin

When the proton number and electron number are unequal, the atom or molecule _____.

is an ion

The nucleolus __________.

is rich in ribosomal RNA

The maximum size of a cell is limited by _____.

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

Cholesterol belongs to which class of molecules?

lipids

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

Which of the following organelles is found only in animal cells and NOT in most plant cells?

lysosome

Which of the following correctly matches an organelle with its function? The __________ functions in __________.

lysosome ... recycling of damaged organelles

Mitochondria appear in the greatest numbers in cells that are _____.

metabolically active

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

microfilament

The internal skeleton of a cell is composed of _____.

microtubules, intermediate filaments, and microfilaments

Which cell structure is responsible for metabolism?

mitochondrion

Which four elements are the primary components of important biological molecules, such as proteins, carbohydrates, and lipids?

nitrogen, carbon, hydrogen, and oxygen

Is fructose a disaccharide?

no

The membranes of the endoplasmic reticulum are continuous with the membranes of the __________.

nuclear envelope

Ionic bonds form when _____.

one atom transfers an electron to another atom

A covalent bond is likely to be polar if _____.

one of the atoms sharing electrons is much more electronegative than the other

Organism is to community as organ is to _____.

organ system

Structures found within a eukaryotic cell and performing specific tasks are collectively termed __________.

organelles

Double bonds are present in the majority of the fats of which of the following foods?

peanuts

The lipids that form the main structural component of cell membranes are _____.

phospholipids

You have identified a new organism. It has ribosomes, plasmodesmata, and cell walls made of cellulose. This new organism is most likely a(n) __________.

plant

Chloroplasts are found in __________.

plant cells and some protists

Which plant structure is most like gap junctions in animal cells?

plasmodesmata

Cellulose is a _____ made of many _____.

polymer ... glucose molecules

DNA carries the instructions for building _____, and these instructions are found in informational units called _____.

polypeptides ... genes

Which of the following sugars CAN be accurately represented by the formula C6H12O6?

possibly glucose or fructose

Which of the following foods would contain the most starch?

potatoes

Which of the following would distinguish a bacterial cell from an animal cell?

presence of a cell wall

Which of the following subatomic particles contributes toward the atomic mass of hydrogen?

proton

Two atoms of the same element must have the same number of _____.

protons

A polar covalent bond _____.

results from the unequal sharing of electrons

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

secrete a lot of material

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

starch ... cellulose

The plasma membrane would fit into which general function category?

support, movement, and communication

Which of the following is a function of the rough endoplasmic reticulum?

synthesizing receptor proteins

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

Which of the following would be affected when a protein is denatured?

tertiary structure

To be of value to science, hypotheses must be __________.

testable

Generally, what determines the number and kinds of chemical bonds an element can make and the chemical reactivity of an element?

the number of electrons in its outer shell

In a group of water molecules, hydrogen bonds form between _____.

the oxygen atom in one molecule and a hydrogen atom in another molecule

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

the plasma membrane

Which microscope would be best suited to the measurement of the internal structures of a bacterial cell?

transmission electron microscope

Which of the following structures is essential for the successful operation of the endomembrane system?

transport vesicles

A fatty acid containing at least one double bond is called _____.

unsaturated

When an RNA strand forms using DNA as a template, _____.

uracil pairs with adenine and cytosine pairs with guanine

When two monosaccharides link to form a disaccharide, the by-product is __________.

water

Which of the following clues would tell you whether a cell is prokaryotic or eukaryotic?

whether or not the cell is partitioned into compartments by internal membranes