Biology Chap. 1-3 Questions

Triglycerides vary with respect to the number of ...

(b) C atoms in the tails. (c) double bonds in the tails.

The ammonia molecule in the diagram has the observed bond orientation because ...

- N has 7 protons in its nucleus. - N has four pairs of electrons in the valence shell. - electrons repel one another.

what is true of chemical reactions

- reactants (Lt of arrow) yield products (Rt of arrow) - result in the rearrangement of atoms - there are always the same number of atoms of each element on both sides of the arrow

which of the following processes occurs in BOTH eukaryotic and bacterial cells

- uptake of energy from their surroundings - regulation of cell function by changes in the activity of genes - reproduction

Polar attractions are ...

-forces between atoms with partial charges. -weaker than covalent bonds. -important because they are numerous.

An electrically neutral molecule has the formula C3H4O2N. If the carbon atoms form the usual number of bonds, how many covalent bonds will each hydrogen atom have with other atoms in the molecule?

1

An atom has 8 protons, 8 neutrons, and 8 electrons. Another isotope of the same element might have ...

10 neutrons.

To fill the valence shell, an electrically neutral, unbonded atom with atomic number 8 must add ...

2 electrons

Proteins are made of sequences of _____ amino acids. DNA consists of sequences of ____ nucleotides

20 ; 4

An atom's atomic number is 7. Its valence is most likely ...

3

In molecules, C, H, O, and N atoms usually make __, __, __, and __ bonds respectively.

4, 1, 2, 3

The "backbone" of the RNA molecule consists of ______.

5-carbon sugars, plus phosphate groups

An isotope of carbon has 6 proteins, 7 neutrons and 6 electrons. Its atomic number is ____ and its mass number is ______.

6 ; 13

States the equation for photosynthesis in words

6 molecules of carbon dioxide gas combine with 6 molecules of water to form 1 molecule of glucose and 6 molecules of oxygen gas

The mass number of an atom is 15, and its atomic number is 7. The atom probably has...

8 neutrons in the nucleus

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

8; 17

Which of the following helps most to explain why water has a high specific heat?

A water molecule can make 4 hydrogen bonds.

Two C atoms form a double bond. Each C is bound to two H atoms. Which statement is true?

All the atoms lie in a plane.

Lactase deficiency is more common in Asian, Native American, Mediterranean and some African populations than it is among people with northern or western European ancestry. How would you explain why this is so?

Although most mammals, including humans, are not able to digest the milk sugar, lactose, after infancy, the ancestors of northern and western Europeans relied on dairy products as an important part of their food supply. When other food sources were in low supply, mutations that allowed the expression of the enzyme lactase to persist past childhood conveyed an advantage to adults who were able to include dairy products in their diet.

Some athletes use anabolic steroids to build their body mass. Why is this considered a problematic practice, especially in adolescents?

Anabolic steroids can prevent bone growth.

Prokaryotic cells are found in the domain ______

Bacteria and Archaea

Select the hydrocarbon from the following choices. C3H8 CO2 H2CO3 C6H12O6

C3H8

Which of the following molecules is a carbohydrate? C51H98O6 C22H49O10N5 C60H100O50 C45H84O8P4

C60H100O50

An atom has 6 electrons, 6 protons, and 6 neutrons. You can tell that this atom belongs to the element _____ because _____________________.

C; it has 6 protons.

_____ is the most abundant organic compound on Earth.

Cellulose

many adults of Asian, African and European descent CANNOT produce lactase, the enzyme that digests the milk sugar lactose. However, some groups of adults in both East Africa and Northern Europe are able to digest lactose. this is an example of what

Convergent evolution

what is the molecular commonality that is the basis of life's variety

DNA

____ is to science as ____ is to engineering

Discovery; invention

Which statement is true of atoms?

Electrons determine the atom's size.

Fungi are classified into which domain

Eukarya

which domain(s) include unicellular organisms

Eukarya, Archaea, and Bacteria

A human is classified in domain ____ and kingdom _____

Eukarya; Animalia

A rose bush is classified in domain ____ and kingdom ____.

Eukarya; Plantae

a small group of predatory birds populates an island. three members of the population have superior sight, which gives these birds a significant advantage in capturing pray........

Evolutionary adaption

In a study of factors that might contribute to heart disease, a relative risk of 1.75 for factor X indicates which of the following?

Factor X is strongly associated with heart disease

What i8s the result of the body's signaling system that controls insulin secretion to drive cellular work?

Glucose levels in blood fall, while glucose levels in the body's cells increase

If you want a molecule that is highly polar, look for one that contains:

H-N

Table salt is often supplemented with which trace element that halts the condition shown below? (goiter)

Iodine

Why isn't the Theory of Evolution referred to as the "Hypothesis of Evolution"?

It is very broad in scope Hypothesis are very narrow in scope as compared to theories

which of the following is a true statement about the thumb of the red panda?

It represents an adaptation to enable the animal to move along trees, not an adaptation for grasping

Which of the following statements regarding lactose tolerance is true?

Lactose tolerance has evolved independently in multiple different human populations.

What do fats, steroids, and waxes have in common?

Low solubility in water.

Which of the following is a statement that uses qualitative data?

Mary's favorite color is blue Qualitative data describes something about the subject; NOT measuring or counting

Which of the following atoms can form the most covalent bonds with another atom? The number of electrons in each atom's valence shell is provided.

N(5)

Can science progress without technology?

No; because scientists need technology to conduct research

Which answer correctly ranks the atoms in terms of decreasing electronegativity (the highest electronegativity first)

O, N, C, H

Use your knowledge of electronegativity to pick out the most polar bond in the list below. N-H O-H C-H O-C O-N

O-H

How are ionic bonds formed?

One atom gives up an electron to a more electronegative second atom

Which of the following choices includes elements that each contribute at least 10% of the human body?

Oxygen (65%); Carbon (18.5%); Hydrogen (9.5%)

The reaction that is essential to life on Earth?

Photosynthesis

Which of the following is incorrect pairing of a kingdom of an organism and the nutrient source of that organism

Plantae: decompose organic waste

Why doesn't oil mix with water?

Polar molecules attract one another.

A single-celled eukaryotic organism that does not decompose or eat other organisms is most likely a member of ____.

Protista

Which of these is NOT a lipid? RNA phospholipid cholesterol steroids wax

RNA

In the Biosphere 2 experiments, scientists varied the carbonate ion concentrations in a coral reef system while holding other factors (pH, temp., & Ca ion concentration) constant. They measured the rates of calcification in the system. What was the dependent variable in these experiments?

Rate of Calcification

What is the shape of a 6-carbon sugar molecule dissolved in an aqueous solution?

Ring

Your Uncle Eddie likes to put a lot of sugar in his coffee. When he does so, he is making a _____ in which the coffee is the ______ and the sugar is the ______.

Solution, Solvent, Solute

Which of the following substances is a compound?

Table Salt (NaCl)

Anabolic steroids are synthetic versions of the hormone ____. To which the following persons can they be appropriately prescribed?

Testosterone; people who suffer from muscle-destroying diseases

Which answer helps to explain why carbon atoms tend to make 4 covalent bonds?

The valence shell needs 8 electrons.

What do DNA, proteins, and fats have in common?

They contain carbonyl groups.

Which of the following statements is true about compounds?

They contain two or more elements in a fixed ratio to each other.

Which of the following best describes the structure of DNA?

Two polynucleotide chains twisted into a double helix

Dr. Haxton told one of his students, "To move in the bloodstream, fats need the help of phospholipids." What would a good student say?

Yes. Nonpolar molecules aren't compatible with water.

a nucleotide consists of which of the following

a 5-carbon sugar. a phosphate group. and a base containing nitrogen

Dissolving is best described as ...

a mingling of molecules and/or ions.

Glycogen is _____.

a polysaccharide found in animals

The 4 nucleotides of DNA include:

adenine, guanine, thymine, & cytosine

In the DNA molecule, thymine always bonds with _____ while cytosine always bonds with ______.

adenine; guanine

human proteins, such as insulin, can be produced by bacterial cells. this is possible because

all organisms share a common genetic code

Protein polymers are made up of _____ monomers.

amino acid

Proteins are polymers of _____.

amino acids

A peptide bond forms when the carboxyl group of one amino acid joins with the ______ group of another amino acid in a _______ reaction.

amino; dehydration

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

an aqueous solution

Radioactive decay is likely to occur when ..

an atom has too many neutrons.

The most common form of calcium has 20 protons, 20 neutrons, and 20 electrons. Which of the following elements would be an isotope of calcium?

an atom with 20 protons, 21 neutrons, and 20 electrons

The open spaces in water's crystal structure make it possible for ...

aquatic life to exist at the North Pole.

Trace elements _____.

are required in very small amounts

A function of cholesterol that does not harm health is its role _____.

as a component of animal cell membranes

Carbohydrates are mainly used in our bodies _____.

as fuel

What is happening to the molecular bonds in water as the ice cubes in your soda melt

as the ice melts, the hydrogen bonds between water molecules change so that the molecules are packed closer to each other

In the chemical reaction shown below, _____. 2 H2 + O2 ---> 2 H2O

bonds are broken and made

What do phospholipids and cholesterol have in common

both are important components of cell membranes Cholesterol is a steriod

How do bases act to reduce the concentration of hydrogen ions in a solution?

by donating OH- ions or by accepting H+ ions

Hydrogen bonds ... a)occur within a water molecule. b)are covalent bonds. c)can form between H and N. d)share electrons between the two bonded atoms. e)All of the above.

c)can form between H and N.

what is the difference between a carbohydrate and a hydrocarbon

carbohydrate molecules contain carbon, oxygen, and hydrogen

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

carbon

Which of the following statements about carbon skeletons is true?

carbon skeletons may take the shape of a ring

Which of the following functional groups of organic molecules consists only of a carbon atom double-bonded to an oxygen atom?

carbonyl

at which level of interaction does life first appear

cell

which series of terms is in the sequence of biological organization from the simplest to the most complex

cell, tissue, organ, population

Which of these is a polysaccharide? glucose lactose cellulose galactose sucrose

cellulose

which of the following occurs when a gene is transcribed

complementary base sequences are copied onto RNA

Quaternary structure can be observed in proteins that have which of the following characteristics?

composed of more than one polypeptide chain

which of the following choices lists chemical bonds from strongest to weakest

covalent, Ionic, Hydrogen

What is another name for a condensation reaction?

dehydration

The _______ reaction that occurs when two monomers combine to form a polymer releases molecules of ______.

dehydration; water

DNA has the appearance of a _____.

double helix

Covalent bonds hold atoms together because they ... (a) fill shells without giving atoms much charge. (b) bring electrons closer to protons. (c) use forces between nuclei as well as forces between electrons. d)do all of the above. e) do both (a) and (b).

e) do both (a) and (b).

Which of the following has the smallest mass?

electron

In a double covalent bond, a carbon atom shares ...

electrons in two orbitals.

A neutral atom differs from its ionized form in the number of _____. The isotopes of an element differ in the number of ____.

electrons; neutrons

A substance that cannot be broken down into other substances by ordinary chemical procedures is known as a(n) _____

element

Energy within the most ecosystems flows along which of the pathways?

energy from the sun powers photosynthesis; consumers use energy from plants in the form of sugars; metabolic heat is released from the system

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

evolution

Which of the following statements is true regarding trace elements

excessive amounts of trace elements can damage the body

consider the shape of proteins. Enzymes are usually _____, while structural proteins are usually _____.

globular; fibrous

In fat synthesis,________and fatty acids combine to make fats plus________.

glycerol; water

By making two covalent bonds, an O atom (with 8 protons) fills its valence shell. Why does the atom's charge stay close to zero?

hared electrons aren't always near oxygen.

Which statement is true of the energy levels of electrons in shells?

he valence shell has higher energy than other occupied shells.

Water is a source of ______________ for chemical reactions in cells.

hydrogen &oxygen atoms

The secondary structure of a protein results from _____.

hydrogen bonds

The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases.

hydrogen bonds

Water has surface tension because ...

hydrogen bonds between surface water molecules resist being stretched.

What is the name of the process during which a bond between two monomers is broken?

hydrolysis

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

hydrophobic

In the reaction that builds a fat,________ groups react with ________ groups.

hydroxyl; carboxyl

Because the molecules of water are farther apart in ice than in liquid water, _____.

ice floats

Defensive proteins are manufactured by the _____ system.

immune

Which of the following statements about chemical reactions is NOT true

in some chemical reactions, matter is created

The levels of carbon dioxide are expected to _____ of our oceans.

increase and lower the pH

How did individual variations in traits among member of a population contribute to Darwin's view that natural selection is the mechanism of evolution

individual variation allows favorable traits to become increasingly common in the population over time

which of the following describes the use of a radioactive tracer to diagnose a disease

injecting a tracer that binds to beta-amyloid plaques in the brain

What, if any is the effect on coral reefs of excess CO2, which is produced by the burning of fossil fuels?

it acidifies t5he ocean and harms coral reefs

Why can't humans digest cellulose?

it contains hydrogen bonds

Though you add heat, the temperature of boiling water remains constant because ..

it takes energy to break hydrogen bonds

which component of an amino acid provides its acidic properties

its carboxyl group

A food company hydrogenated a barrel of fat. The treatment ...

made the fat less fluid.

"Gene Expression" refers to _______

making a protein using the instructions in DNA

glucose + glucose —> _____ by _____.

maltose + water ... dehydration synthesis

Which of these is a source of lactose?

milk

Some lines of evidence supported classifying the red panda in the same family as raccoons, while other lines support classifying it with giant pandas. What kind of evidence was used to "settle" the matter?

molecular evidence

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

nitrogen, carbon, hydrogen, and oxygen

the bond between the two hydrogen atoms in an H2 molecule are _________. The bonds between two O2 molecules are _________.

nonpolar; nonpolar

Nucleic acid polymers are made up of ____ monomers.

nucleotide

DNA is composed of building blocks called _____

nucleotides

Which of these is rich in unsaturated fats? butter beef fat a fat that is solid at room temperature olive oil lard

olive oil

there is (are ____ eukaryotic domains

one

Organism is to population as organ is to _____.

organ system

which of the following statements is NOT true about discoveries that have been made as a result of comparison of DNA sequences across many species

organisms possessing a genetic code drastically different from that used by humans have been discovered

Which of these does NOT contain a structural protein? tendons muscles ovalbumin ligaments spider silk

ovalbumin

What type of bond joins the monomers in a protein's primary structure?

peptide

Tertiary structure is NOT directly dependent on _____.

peptide bonds

Local farmers believe that a commonly used pesticide is responsible for an increase in frogs born with an additional appendage on their land. In a controlled experiment designed to investigate the effects of the pesticide on frog development, the independent variable would be _____.

pesticide exposure; number of frogs with extra appendages

A nucleotide is composed of a(n) _____.

phosphate group, a nitrogen-containing base, and a five-carbon sugar

Which statement must be mentioned in explaining why amphipathic molecules line up at a water surface?

polar groups attract one another.

Chemists assign atoms to chemical elements by counting their ________.

protons

Properties of living things

reproduction, growth and development, energy use, order, cells, response to the environment, evolution

Without making or breaking bonds, the pictured molecule can change its shape because ...

rotation can occur around single bonds.

Carbohydrate polymers are made up of _____ monomers.

simple sugar

Saturated fats are semi-solid at room temperature, whereas unsaturated fats are usually liquid. Why?

single C-C bonds allow the molecules to "pack together"

water strider can move swiftly across a pond without breaking the water's surface. This is due to their light weight and the water's __________.

surface tension

why does sweating cool us?

sweating allows the water molecules with the highest energy to leave the body first

Which component of a protein is primarily responsible for its shape?

the R groups in the chain

When hot, many mammals sweat to control their body temperature. Evaporation contributes to temperature moderation, but mammals' ability to control their body temperature is mainly due to __________.

the absorption of heat by the breaking of hydrogen bonds

technology is _________

the application of scientific knowledge for some specific purpose

In the "Tree of Life" figure 1.9C what is located at each branching point?

the common ancestor of all animals who are placed to the right of that point

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 the "thumb"

Dr. Jones says an atom has 3 electrons in the first shell and four electrons in the second shell. Someone should tell Dr. Jones that ...

the first shell shouldn't have 3 electrons.

The most unsaturated fats have ...

the most double bonds.

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

Two atoms always represent the same element if they have ...

the same number of protons.

Glucose and fructose are isomers. What does this tell you about the two molecules?

they have the same molecular formula

Consider a white blood cell. The next level of organization above it in the "Hierarchy of Life" is the _____ nd the next level below it is the _____.

tissue; organelle

what is not a property of living things?

tremendous variation in size

Which of the following is one way that an understanding of evolution can directly improve human health?

understanding the "survival strategies" of a virus can guide development of a more effective vaccine

Astrobiologists searching for signs of life on other planets primarily search for __________.

water

Which statement is true of water's tensile strength?

(a) It results from hydrogen bonding. (b) It helps to pull water through plants. (c) It involves both cohesion and adhesion.

Which factor is important in making it possible to cool yourself by sweating? Think carefully!

(a) Molecules collide with varied angles and speeds. (b) Hydrogen bonds are relatively weak.

Which statement helps to explain why ice is less dense than liquid water?

(a) Water molecules make hydrogen bonds at definite angles. (b) Cold molecules move less than warm molecules.

Partial charges occur when .

(a) a covalent bond links atoms of two kinds. (b) atoms share electrons unequally.

Polymers that contain sugars ...

(a) may store hereditary information. (b) may store energy. (c) may protect cells.

The presence of many C-C and C-H bonds causes fats to be ..

(a) rich in energy. (b) insoluble in water.