Biology Exam 1 (chapters 1-5)

Cells are

characteristic of prokaryotic and eukaryotic organisms

Prokaryotes are classified as belonging to two different domains. What are the domains?

bacteria and archaea

Which of these provides evidence of the common ancestry of all life?

near universality of the genetic code

Which of the following is/are true of natural selection?

It requires genetic variation, results in descent with modification and involves differential reproductive success

Charles Darwin proposed a mechanism for descent with modification that stated that organisms of a particular species are adapted to their environment when they possess

heritable traits that enhance their survival and reproductive success in the local environment

The best experimental design

includes a large sample size and a control, and alters only one condition between the controls and the experimental condition

Which of the following are qualities of any good scientific hypothesis?

I. It is testable

II. It is falsifiable

III. It produces quantitative data

IV. It produces results that can be replicated

I. It is testable

II. It is falsifiable

How does a scientific theory differ from a scientific hypothesis?

Theories are usually an explanation for a more general phenomenon; Hypothesis typically address more scientific issues.

Which of these is an example of inductive reasoning?

Hundreds of individuals of a species have been observed and all are photosynthetic therefore, the species is photosynthetic

Why is scientific topic best discussed by people of varying points of view? from different disciplines and representing diverse cultures?

Robust and critical discussion between diverse groups improves scientific thinking

About twenty five of the ninety two elements are known to be essential to life. Which four of these twenty five elements make up ninety six percent of living matter?

Carbon, Hydrogen, Nitrogen, Oxygen

Trace elements are those required by an organism in only one minute quantities. Which of the following is a trace element that is that is required by humans and other vertebrates, but not by other organisms such as bacteria or plants?

Iodine

Knowing the atomic mass of an element allows inferences about which of the following?

the number of protons plus neutrons in the element

Which of the following are compounds?

H2O and CH4 but not O2

Carbon-12 is the most common isotope of carbon and has a mass number of 12. However, the average atomic mass of carbon found on periodic table is slightly more than 12 daltons. Why?

some carbon atoms in nature have more neutrons

If you change the number of neutrons in an atom, you create...

an isotope

Can the atomic mass of an element vary?

Yes, by adding or losing neutrons will change the atomic mass without forming a different element

Bonds between two atoms that are equally electronegative are...

non polar covalent bonds

What results from an unequal sharing of electrons between atoms?

a polar covalent bond

What is the difference between covalent bonds and ionic bonds?

covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms

The partial negative charge in a molecule of water occurs because

the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus

Water molecules can form hydrogen bonds with

compounds that have polar covalent bonds

Which of the following is a property of liquid water?

liquid water has a heat evaporation that is higher than that for most other substances

The cities Portland, OR and Minneapolis, MN are at about the same latitude, but MN has much hotter summers and colder winters than Portland. Why?

the ocean near Portland moderates the temperature

Which of the following effects can occur because of the high surface tension of water?

a raft spider can walk across the surface of a small pond

Which type of bond must be broken for water to vaporize?

hydrogen bonds

Based on your knowledge of the polarity of water molecules, the solute molecule depicted here is most likely

positively charged

Consider the buffering equation at equilibrium: What would be the effect of adding additional H2CO3?

it would drive the equilibrium dynamics to the left

A strong acid like HCl

disassociates completely in an aqueous solution

A solution contains 0.0000001 (10^-7) moles of hydroxyl ions [OH-] per liter. Which of the following best describes this solution?

neutral

The element present in all organic molecules is

carbon

Differences among organisms are caused by differences in the

types and relative amounts of organic molecules synthesized by each organism

Stanley Millers 1953 experiments supported the hypothesis that

organic molecules can be synthesized abiotically under conditions that may have existed on early Earth

When Stanley Miller applied heat and electrical sparks to a mixture inorganic compounds such as methane, hydrogen, gas, ammonia, and water vapor, what compounds are produced?

simple organic compounds, amino acids and hydrocarbons

Why is carbon so important in biology?

it can form a variety of carbon skeletons and host functional groups

How many pairs does carbon share to complete its valence shell?

four

Why are hydrocarbons insoluble in water?

the majority of their bonds are non polar covalent carbon-to-hydrogen linkages

Which of the functional groups below acts most like an acid in water?

carboxyl

Which two functional groups are always found in amino acids?

Carboxyl and Amino groups

Which of the following is a False statement concerning amino groups?

amino groups

are non polar

Which of these classes of biological molecules does not include polymers

lipids

Which of the following is NOT a polymer

glucose

How many molecules of water are used to completely hydrolyze a polymer that is 11 monomers long?

10

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?

hydrolysis reactions break polymers apart

Which polysaccharide is an important component in the structure of many animals and fungi?

chitlin

A molecule with chemical formula C6H12O6 is probably a

monosaccharide

Which of the following statements is False?

saturated fats have many double bonds in the carbon chains of their fatty acids

Saturated fatty acids

are the principle molecules in lard and butter

The molecule illustrated in the accompanying figure

will be liquid at room temperature

Which of the following descriptions best fits the class of molecules known as nucleotides?

a nitrogenous base, a phosphate group, and a sugar