Which of the following things would be considered complex and organized?
Red blood cell in the human body
Living systems need energy to:
-Replace worn-out parts and build new parts.
-Help maintain a relatively constant internal environment
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.
Which of these refers to atoms with the same atomic number but different atomic masses?
These atoms are isotopes
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.
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.
A function of cholesterol that does not harm health is its role...
as a component of animal cell membranes.
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?
The two strands of a DNA double helix are held together by___ that form between pairs of nitrogenous bases.
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.
Fats vary with respect to the number of
-C atoms in the tains
- Double bonds in the tails
What do fats, steroids, and waxes have in common?
-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.
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 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.
It is difficult for molecules to pass through the phospholipid bilayer because
polar molecules attract one another
Which plant cell organelle converts chemical fuel into packets of chemical energy that can power the cell?
___ are found only in plant cells, but___ are found in both plant and animal cells.
Central vacuoles; ribosomes
One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by
What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?
In eukaryotic cells the first step in protein synthesis is the
transferring of information from DNA to messenger RNA
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
A diploid organism whose somatic cells each contain 32 chromosomes produces gametes containing ____ chromosomes.
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)
sister chromatids separate and become full-fledged chromosomes that move to opposite poles
A cell preparing to undergo meiosis duplicates its chromosomes during
interphase (Chromosomes duplicate)
The correct order of events during meiosis is
- telophase I
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)
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
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.
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
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 statement helps to explain how DNA stores hereditary information?
DNA contains four kinds of nitrogenous bases.
Which statement about DNA replication is correct?
The leading strand is built continuously, and the lagging strand is built in pieces.
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.
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 _______.
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?
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 _______.
What is the function of reverse transcriptase?
It catalyzes the formation of DNA from an RNA template
The process by which information encoded in DNA is converted to information encoded in RNA
gene that encodes proteins that inhibit cell division. Such proteins normally help prevent cells from becoming cancerous