Chapters (1-5, 8-12)
An organ, such as the liver, is composed of
Which of these is an organ system?
What are the two main types of cells?
Prokaryotes and eukaryotes
An example of stimulus that a plant would respond to is:
Which of the following things would be considered complex and organized?
Red blood cell in the human body
DNA is a molecule that directly allows a living thing to
Store information
The process of homeostasis is:
How organisms maintain a relatively constant internal environment.
Living systems need energy to:
-Replace worn-out parts and build new parts.
-Grow larger.
-Help maintain a relatively constant internal environment
The complexity of living systems
is also highly organized
Identify a characteristic that is representative of some, but not all, life-forms.
Movement over great distances.
Which of the following is an example of discovery science?
Observing what other students in your class are wearing.
Which of the following is an example of hypothesis-driven science?
Testing whether or not dead batteries are preventing a TV remote from working.
Prokaryotic cells are found in the domain(s)
Bacteria and Archae
In the five-kingdom system, prokaryotes are placed in the kingdom
A human is classified in domain______ and kingdom _____.
Eukarya and Animalia
A rose bush is classified in domain____ and kingdom_____.
Eukarya and Plantae
In the five-kingdom system, which kingdom consists primarily of unicellular eukaryotes?
In the two-kingdom system, why were fungi classified in the kingdom Plantae?
They are sedentary
There is ___ eukaryotic domain.
Which of these refers to atoms with the same atomic number but different atomic masses?
These atoms are isotopes
A ____ refers to two or more atomd held together by covalent bonds.
The innermost electron shell of an atom can hold up to____electrons.
Which of these relationships is true of an uncharged atom?
The number of protons is equal to the number of electrons.
What determines the types of chemical reactions that an atom participated in?
The number of electrons in the outermost electron shell.
Atoms with the same number of protons but different electrical charges
are different ions
In salt(NaCL) what is the nature of the bond between sodium and chlorine?
An ionic bond involves
an attraction between ions of opposite charge.
What name if given to the bond between water molecules?
Hydrogen bond
The unequal sharing of electrons within a water molecule makes the water molecule
The tendency of an atom to pull electrons toward itself is referred to as its
In a neutral solution the concentration of
hydrogen ions is greater than the concentration of hydroxide ions.
What is dehydration synthesis?
The process of linking monomers; The removal of two hydrogen atoms and one oxygen atom to form water.
Glycogen is:
a polysaccharide found in animals
Maltose+Water (dehydration synthesis)
Which of these is a polysaccharide?
______ is the most abundant organic compound on Earth.
Which of these is not a lipid?
A function of cholesterol that does not harm health is its role...
as a component of animal cell membranes.
Protein are polymers of
amino acids
What type of bond joins the monomers in a proteins primary structure?
The secondary structure of a protein results from
hydrogen bonds
Tertiary structure is not directly dependent on
peptide bonds( Primary structure is)
If a strand of DNA has the nitrogen base sequence 5'ATTTGC'3, what will be the sequence of the matching strand?
If DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain?
75 (200-50/2)
The two strands of a DNA double helix are held together by___ that form between pairs of nitrogenous bases.
hydrogen bonds
A nucleotide is composed of a
-Phosphate group
-Nitrogen-containing base
-five-carbon sugar
Cellulose is..
Made with glucose that has the beta ring form.
occurs in animal cells and has branches.
Which fact is most important in explaining why cellulose is better structural material than starch?
Alpha-linkages make it easier for the polymer to coil into a helix.
A cotton shirt is chemically most similar to a
sugar cube
The presence of many C-C and C-H bonds causes fats to be
-rich in energy
-insoluble in water
In fat synthesis,______ and fatty acids combine to make fats plus_____.
Glycerol; water
In the reaction that builds a fat __ groups react with_____ groups.
Hydroxyl; carboxyl
Fats vary with respect to the number of
-hydrocarbon tails
-C atoms in the tains
- Double bonds in the tails
A food company hydrogenated a barrel of fat. The treatment
made fat less fluid.
The most unsaturated fats have
the most double bonds.
What DNA, proteins, and fats have in common?
Carbonyl groups
What do fats, steroids, and waxes have in common?
-Moderate polarity
-Low solubility in water
-They occur in membranes
Dr. Haxton told one of his students, "To move in the bloodstream, fats need the help of phospholipids" What would a good student say?
Correct. Nonpolar molecules aren't compatible with water.
What does cholesterol have in common with sex hormones?
Four linked rings.
For good health you dont want your body to run the LDL faster than the HDL because
LDL cholesterol is stored;HDL cholesterol is destroyed.
Which of these does NOT contain a structural protein?
DNA is composed of building blocks called
Dna has the appearance of a
double helix
Which statement is true of polymers?
They are always made of monomers.
The organic molecule called DNA is an example of
a polymer made of nucleotides
Phospholipids are most important for
preventing leakage from cells
To find the best source of phospholipids look at
What do phosphoglycerides and fats have in common?
Ester linkages.
Which statement is true of phospholipids?
-Their synthesis uses fatty acids
-Some of their tails have double bonds
-They all ionize
Which fact is most important in causing phospholipids to behave as they do in water?
Water molecules make hydrogen bonds
In a membrane, the____ of the phospholipids in one monalayer face the_____ of the phospholipids in the other monalayer.
Tails; tails
It is difficult for molecules to pass through the phospholipid bilayer because
polar molecules attract one another
Which lipid is most amphipathic?
Which plant cell organelle converts chemical fuel into packets of chemical energy that can power the cell?
The plant cell wall
is a protective structure made of cellulose fibrils.
Which of the following is a function of the central vacuole?
Storing compounds produced by the cell
___ are found only in plant cells, but___ are found in both plant and animal cells.
Central vacuoles; ribosomes
The structural framework in a cell is the
Where in a cell is ATP made?
What carries instructions for making proteins from the nucleus into the cytoplasm?
One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by
Which of the following is part of the endomembrane system?
Golgi apparatus
Which of the following organelles breaks down worn-out organelles?
Where are lipids made in the cell?
smooth endoplasmic reticulum (ER)
What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?
plasma membrane
In eukaryotic cells the first step in protein synthesis is the
transferring of information from DNA to messenger RNA
Function of nucleus
stores genetic information of the cell
breaks down macromolecules using digestive enzymes
converts chemical fuel into packets of chemical energy that can power the cell
works with mRNA to synthesize proteins
Smooth ER
site of lipid synthesis
Golgi apparatus
modifies and packages proteins
the movement of particles down their concentration gradient.
passive transport of water
A vesicle inside the cell fuses with the plasma membrane and releases its contents outside of the cell.
The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell
Active transport
Requires energy from the cell. Molecules move against their concentration gradient
Gametes are produced by
Normal human gametes carry __ chromosomes.
A diploid organism whose somatic cells each contain 32 chromosomes produces gametes containing ____ chromosomes.
Bacteria divide by
binary fission
What must happen before a cell can begin mitosis?
The chromosomes must be duplicated.
The centrosomes move away from each other and the nuclear envelope breaks up during which phase of mitosis?
Prophase (Centrosomes begin moving toward opposite poles and the nuclear envelope breaks up)
The chromosomes line up in the center of the cell during which phase of mitosis?
Metaphase (Chromosomes line up in the middle of the cell)
The sister chromatids separate and begin moving toward opposite poles of the cell during which phase of mitosis?
Anaphase (Sister chromatids separate and start their migration toward opposite poles)
The chromosomes arrivee at the poles and nuclear envelopes form during which phase of mitosis?
Telophase (The nuclear envelopes of the two new cells form)
At the end of the mitotic phase, the cytoplasm divides in a process called
Mitosis interphase
cells divide replicate their DNA
Mitosis prophase
microtubles form the mitotic spindle, and the nuclear envelope breaks up.
Mitosis metaphase
Chromosomes line up in the center of the cell.
Mitosis anaphase
sister chromatids separate and become full-fledged chromosomes that move to opposite poles
Mitosis telophase
Nuclear envelopes form, cytokinesis.
Nucleoli are present during
Cytokinesis often, but not always, accompanies
Chromosomes become visible during
Meiosis starts with a single diploid cell and produces
four haploid cells
A cell preparing to undergo meiosis duplicates its chromosomes during
interphase (Chromosomes duplicate)
During prophase I of meiosis
homologous chromosomes stick together in pairs.
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 (Segments of nonsister chromatids trade places, resulting in recombination)
Monohybrid cross
genetic cross involving parents that differ in a single character
gene alternate
Dominant allele
version of a gene that is expressed in the organism
Recessive allele
version of the gene that is not expressed in the organism
physical traits of an organism
genetic makeup of an organism
Mendel formulated his principles of inheritance based on
observations on the outcomes of breeding experiments. The underlying processes were unknown at the time.
Mendel observed that pair of alleles were separated or segregated in gametes and that they were rejoined in fertilization. We know that pairs of ___________ are segregated in _________ and then are rejoined through fertilization
homologous chromosomes....meiosis
As we now understand it, the Law of Independant Assortment applies
to pairs of genes that are on different chromosomes, but NOT to pairs of genes that are close together on the same chromosome.
How have Mendel's law fared as we have learned more about cell biology and processes such as meiosis?
Our new knowledge has helped to explain some of the exceptions to Mendel's laws of inheritance.
Which of these correctly illustrates the pairing of DNA and RNA nucleotides?
The direction of synthesis of RNA transcript is
The tRNA anticodon, GAC, is complementary to the mRNA codon with the sequence
The initiator tRNA attached at the ribosome's __ site
How do mutations affect an organism?
-They may cause the development of a disease-causing allele
-They may cause the development of a more beneficial allele
- They, in some cases, may have no noticeable affect
DNA replication occurs at an unbelievably fast rate. Once replication is complete, we can expect to find a ____ number of mistakes
A female that is planning to become pregnant is concerned about her exposure to environmental mutagens which may have caused DNA mutations. In order for these mutations to become heritable, they must affect
her egg cells
Which of the following would indicate a base pairing mutation in DNA?
G paired with a T
In a DNA double helix an adenine of one strand always pairs with a_______ of the complimentary strand, and a guanine of one strand always pairs with a _____ of the complementary strand.
Which of these is a difference between DNA and RNA?
DNA is double-stranded, whereas RNA is single-stranded
Which of these nitrogenous bases is found in DNA but not RNA?
RNA nucleotides contain______ than DNA nucleotides.
more oxygen
Which statement helps to explain how DNA stores hereditary information?
DNA contains four kinds of nitrogenous bases.
DNA and mRNA differ with respect to
the kind of sugar they contain.
Which of the following builds new strands of DNA?
DNA polymerases
Which statement about DNA replication is correct?
The leading strand is built continuously, and the lagging strand is built in pieces.
During DNA replication, which nucleotide will bind to an A nucleotide in the parental DNA?
The molecule that seals the gaps between the pieces of DNA in the lagging strand is
DNA ligase
Which statement about DNA replication is correct?
- Because the two strands of parental DNA run in opposite directions, the new strands must be made in different ways.
-The lagging strand is made of a series of pieces that must be joined together to make a continuous strand
-The two stands of parental DNA are separated during DNA replication
-DNA polymerase builds a new strand by adding DNA nucleotides one at a time.
Genes provide the information needed to produce ______ in the cell
How many enzymes are typically produced from a single gene?
The central dogma describes how the genes in the nucleus work to produce an organism's phenotype. Another way of putting it is that the central dogma follows the flow of information from _______.
DNA replication
A gene is a sequence of DNA nucleotide bases that codes for a single protein. Appromately how many nucleotide bases would be required to code for a protein chain that is 100 amino acids long?
tRNA molecules work to
translate mRNA to produce a specific amino acid sequence
A particular gene does not constantly churn out the same protein at all times in every cell. First,___ can allow one gene to produce several different proteins. Second, genes are constantly being turned on and off through the process of _______.
mRNA reprocessing...transcription
The genetic material of HIV consists of
single-stranded RNA
What is the function of reverse transcriptase?
It catalyzes the formation of DNA from an RNA template
What is the source of a viral envelope?
host cell membrane
What enzyme is responsible for the process seen here?
Reverse transcriptase
Double-stranded viral DNA is incorporated into a host cell as a
The process by which information encoded in DNA is converted to information encoded in RNA
What is a carcinogen?
Substances that cause cancer.
_______ is a carcinogen that promotes colon cancer.
When DNA from two sources is combined into one single piece of DNA, it is known as
Recombinant DNA
The RP13 gene of chromosome 17 codes for a protein
involved in eye development
The TP53 gene of chromosome 17 codes for a protein
involved in the regulation of the cell cycle
Which of these genes codes for a protein that plays a role in growth?
Which of these genes codes for a protein that plays a role in white blood cell function?
normal gene that, if mutated, can lead to cancer
gene that causes a cell to become cancerous
Tumor-suppresor gene
gene that encodes proteins that inhibit cell division. Such proteins normally help prevent cells from becoming cancerous
Growth factor
protein that promotes cell division. In excess, such a protein may lead to cancer