The phospholipid molecules of most membranes have a:
Hydrophilic head and two hydrophobic tails.
A hypothetical "microbullet" shot through a phospholipid bilayer would pass the components in which order?
Head-Tail-Tail-Head
Most of the functions of plasma membrances are carried out by:
Proteins
A water-soluble hormone would most likely bind to which of the following membrane proteins?
Receptor
Oxygen, carbon dioxide, and other small nonpolar molecules cross the plasma membrane through the process(es) of:
Diffusion
Movement of a molecule against a concentration gradient is:
Active Transport
The carrier molecules used in active transport are:
Proteins
A single-cell freshwater organism, such as protistan, is transferred to saltwater. Which of the following is likely to happen?
The cell shrinks
A cell placed in a hypotonic solution will:
swell
If a plant cell is placed in a hypotonic solution, the
turgot pressure will increase, but the cell wall prevents the cell from exploding
Side A contains a 3% sucrose solution and side B has a 10% sucrose solution. The membrane separating the sides is permeable to water but impermeable to sucrose. Side A is ____ to side B.
Hypotonic
Side A contains a 3% sucrose solution and side B has a 10% sucrose solution. The membrane separating the sides is permeable to water but impermeable to sucrose. Describe the movement of water in this system:
Water moves in both directions, but net movement is from A to B
Strictly speaking, mitosis and meiosis are divisions of the:
Nucleus and chromosomes
Chromosomes and genes are replicated during
interphase
Cells with two of each kind of chromosome are described by the term
diploid
What is the proper sequence of mitosis:
Prophase, metaphase, anaphase, telophase
Asexually produced daughter cells are
indentical to each other and to the parental cell
Difference, or alternative, forms of the same gene are
alleles
Homologous chromosomes
Pair up during meiosis; have alleles for the same characteristics even though the gene expression may not be the same; are in pairs, one chromosome of each pair from the father and one from the mother; separate from each other during meiosis I
Crossing over occurs during
prophase I
Paired homologous chromosomes are found at the spindle equator during
metaphase I
If a child more strongly resembles one parent's physical traits than the other parent's, the explanation could be due to chromosome movements during
anaphase I
Which of the following is not true of human chromosomes?
Human gametes end up with two of each type of 23 chromosomes
In Mendel's time, most people believed that
the characteristics of parents were blended in the offspring
Various forms of a gene at a given locus are called:
Alleles
The most accurate description of an organism with genotype AaBb is
heterzygous
In a Punnett square, the letters withing the little boxes represent:
Offspring Genotypes
Is R is dominant to the r, the offspring of the cross of RR with rr will display the same phenotype as:
the RR parent
An individual with a genetic makeup of aaBB is said to be:
Purebread
An individual with a genotype of Aa Bb CC is able to produce how many different kinds of gametes?
4
An animal has the genotype of Aa Cc DD gg. How many different gametes can it produce?
4
Which is the smallest unit of life that can exist as a seperate entity?
cell
The most inclusive level of organization listed here is:
a-organ
b-atom
c-molecule
d-multicelled organism
e-cell
Multicelled Organism
Living organisms are different from inanimate objects because they:
a-react to environmental stimuli
b-exhibit massive complexity
c-possess molecules of deoxyribonucleic acid
d-exhibit multiple levels of organization
e-all of these
all of these
The subatomic particle with a negative charge is:
electron
The subatomic particles with no charge is
the neutron
The Nucleus of an atom contains:
Neutrons and Protons
The atomic number is the number of
Protons only
T or F: All isotopes of an element have the same number of neutrons
FALSE
Magnesium has 12 protons. How many electrons are in its first energy level?
2
Magnesium has 12 protons. How many electrons are in its second energy level?
8
Which includes the other four?
Atoms, molecules, electrons, elements, protons
Molecules
An atom that gains or loses electrons becomes
An ion
True or False: In polar covalent bonds, electrons are shared equally.
False
A dotted line connecting two molecules is a:
Hydrogen Bond
True or False? Hydrogen bonds are difficult to form and break?
False
Hydrophobic molecules are ___ to water.
Repelled
The oil globules that result when a water and oil mixture is shaken are due to a ____ interaction.
Hydrophobic
A reaction of an acid and a base wll produce salt and
water
Which of the following is a naked proton?
A hydrogen ion, an acid, a base, a hydroxyl ion, an oxygen ion
A hydrogen ion
T or F - Radioactive isotopes have an excess number of neutrons
TRUE
The subatomic particle with a positive charge is
proton
The atomic mass of an atom is determined by the combined masses of its
Neutrons and Protons
A single carbon atom may form as many as ___ covalent bonds with other atoms.
4
The atom present in all organic compounds is
carbon
Which is composed of a 1:2:1 ratio of carbon to hydrogen to oxygen?
carbohydrate
Cellulose is a
Polysaccharide found in cell walls
Which of the following includes all the others?
a-sucrose
b-glucose
c-cellulose
d-starch
e-carbohydrate
Carbohydrate
Triglycerides are:
fats
Which of the following are lipids?
Sterols, triglycerides, oils, waxes, all of these
All of these
Amino acids are the building blocks for
Proteins
The sequence of amino acids is the ___ structure of proteins.
Primary
The presence of which of the following features distinguishes prokaryotic cells of eukaryotic cells?
Lack of nuclear membrane
Which of the following organelles is correctly matched with its function?
nucleus:protein synthesis
er: heredity
golgi bodies: packaging
mitochondria: digestion
cholorplasts: storage of lipids
golgi bodies: packaging
Name one of the two main functions of the nuclear envelope?
Allows separation of DNA from cytoplasm machinery
Name something found in the nucleus.
Nucleoli
What is sometimes referred to as rough or smooth depending on structure?
Endoplasmic Reticula
Where are the cells in proteins manufactures?
Rough endoplasmic reticula
What is the primary structure that packages cellular secretions for export from the cell?
Golgi Bodies
What contains enzymes, are the main organelles of intracelular digestion and can digest whole cells?
Lysosomes
What are primary cellular sites for the capture of energy from carbohydrates?
Mitochondria
Which of the following is thought to be the descendant of engulfed ancient bacteria?
Mitochondria
The fluid filled sac that may store food, ions, or water in plant cells and that is also involved in growth and fluid pressure is the:
Central Vacuole
Actin is a structural protein of
Microfilaments
Cilia and flagella are most similar in
their composition and structure
Which scientist identified the transforming substance involved in changing rough bacteria to smooth?
Griffith
Which researcher used viruses in research?
Max Delbruck, Alfred Hershey, Martha Chase, Salvador Luria
All of these
DNA contains ___ but not ____
Phosphorous, sulphur
The experiments of which researchers clearly distinguished DNA and not protein as the hereditary material?
Hershey and Chase
DNA contains all of the following nitrogen containing bases except -
Uracil
If all of the hydrogen bonds in a DNA molecule were to break:
The nucleotide base pairs would separate from each other
The similarity of traits from one generation to another is fundamentally the result of:
semiconservative replication
After three replications of a single DNA molecule, what percent of the resulting molecules contain one strand of the "original" DNA?
25%
DNA from bacteria differs from DNA in humans in which of the following ways?
Nucleotide sequence
A linear stretch of DNA that specifies the sequence of amino acids in a polypeptide is called a:
Gene
___ molecules carry protein assembly instructions from the nucleus to the cytoplasm
Messenger RNA
All the different kinds of RNA are transcribed in the:
nucleus
Which substance is found in RNA but not in DNA?
uracil
The synthesis of an RNA molecule from a DNA template strand is
transcription
The relationship between strands of RNA and DNA is
complementary
Transcription occurs during:
the synthesis of any type of RNA from a DNA template
If the DNA triplets are ATG CGT then the mRNA codons are
UAC GCA
If the DNA triplets are ATG CGT the tRNA codons are:
AUG CGU
What does RNA not have?
Thiamine
If the codon consisted of only two nucleotides, there would be how many different kinds of codons?
16
There are how many different kinds of amino acids in proteins?
20
What carries amino acids to ribosomes, where amino acids are linked into the primary structure of a polypeptide?
tRNA
All mRNA transcrips begin with:
AUG
When cells stop responding to normal controls over growth and division they:
begin to form a tumor
The obvious advantage of the lactose operon is that:
Lactose metabolizing enzymes need not be made when lactose is not present
The prokaryote operon model explains gene regulation at the level of:
transcription
T or F: A structural gene is associated with a lactose operon
F
Small circular molecules of "extra" DNA in bacteria
are plasmids
One of the first successful applications of genetic engineering was the commercial production of:
insulin
According to Lamarck, the characteristics of organisms change because of
an innate drive for perfection
The value of Lyell's ideas on the geologic history of the earth was the
enormous lenths of time required for geologic events
The person credited with being the codiscoverer of evolution by natural selection was
Alfred Wallace
Adhesion proteins not working, cells free to "drift"
Metastasis
Cancer of epithelial cells
Carcinoma
Cancer of connective tissue
Sarcoma
The forelimbs of early mammals are similar in all features except
function
The oldest fossils are:
found buried deepest in the ground
In the nineteenth century, prevailing beliefs came into conflict with findings from all BUT:
plate tectonics
Which of the following was NOT one of Darwin's observations?
Most individuals have an equal chance to survive and reproduce
The person credited with being the codiscoverer of evolution by natural selection was
Alfred Wallace
The word evolution was used in biology literally means
heritable change
Genotype is manifested in
phenotype
T or F: Neutral mutations are not expressed
FALSE
Factors that tend to reduce the size of a population regardless of its inital size are
