Term
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Definition
The nitrogenous bases guanine and adenine are purines, and the
nitrogenous bases cytosine, thymine, and uracil are pyrimidines.
arginine, is an amino acid
and not a nitrogenous base. Amino acids are the building blocks for proteins. |
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Term
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Definition
unusual circulatory arrangements in the body in which there are two interconnected
capillary beds.
In non-portal circulation, blood travels from arteries to a capillary bed and back to a vein.
In portal systems, however, blood travels from an artery to a capillary bed, to a vein, to a second capillary bed,
and back to a second vein. The two most well-known portal systems in the human body are the hepatic portal
system and the hypothalamic portal system. |
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Term
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Definition
The contractile vacuole of Euglena removes excess water from the organism after it comes through the cell
membrane osmotically. In fresh water, the low osmotic pressure drives water inside the organism due to a
higher solute concentration with the Euglena. The organism must use energy (ATP) to force the water back out.
When this organism is transferred to salt water, the solute concentration is greater outside the cell, thus the
osmotic pressure is greater |
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Term
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Definition
Mitosis is cellular division that results in the formation of two daughter cells that are genetically identical to
each other and to the parent cell. The two daughter cells are also diploid (2n). meiosis results in a reduction of chromosome number from 2n to n. It is a process of cell division in
which two successive nuclear divisions produce four haploid gametes from one diploid germ cell. |
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Term
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Definition
| fertilization is the fusion of two haploid (n) gametes into one diploid (2n) zygote. |
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Term
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Definition
non-disjunction results from the failure of homologous chromosomes to
separate during meiosis and the resulting cells have chromosome numbers of n+1 or n–1. |
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Term
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Definition
The Golgi apparatus consists of a stack of membrane-enclosed sacs. The Golgi receives vesicles and their
contents from the ER, modifies them (e.g. glycosylation) and repackages them into vesicles, and distributes
them. |
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Term
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Definition
| mitochondria are involved in cellular respiration |
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Term
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Definition
| ER transports polypeptides around the cell and to the Golgi apparatus for packaging |
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Term
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Definition
| ribosome is the site of protein synthesis |
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Term
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Definition
lysosomes are membrane-bound organelles containing digestive enzymes, and typically have
a low pH. |
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Term
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Definition
The degree of genetic linkage is a measure of how far apart two genes are on the same chromosome. The
probability of a crossover and exchange occurring between two points is generally directly proportional to the
distance between the points. For example, pairs of genes that are far apart from each other on a chromosome
have a higher probability of being separated during crossover than pairs of genes that are located close to each
other. Thus, the frequency of genetic recombination between two genes is related to the distance between them.
Recombination frequencies can be used to construct a genetic map. One map unit is defined as a 1 percent
recombinant frequency. Recombination frequencies are roughly additive. |
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Term
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Definition
Disjunction is defined as the separation of maternal and paternal chromosomes during meiosis. Each tetrad
is separated into two halves. One of each pair of chromosomes, each containing two chromatids, is pulled to
opposite ends of the cell. Note that some of the maternal chromosomes can go to one end and some to the
other end. The distribution of homologues between the two resultant nuclei is random. |
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Term
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Definition
| Unfertilized eggs from the queen bee develop into male bees through parthenogenesis. |
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Term
| Tetrads are formed in this process |
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Definition
During prophase I of meiosis I, homologous chromosomes come together and intertwine in a process
called synapsis. Since at this stage each chromosome consists of two sister chromatids, each synaptic pair of
homologous chromosomes contains four chromatids, and is therefore often called a tetrad. |
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Term
| Fusion of the nuclei of two gametes |
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Definition
Fertilization is defined as the fusion of nuclei of two gametes to form a zygote capable of becoming an adult
organism. |
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Term
| May result in the formation of polar bodies |
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Definition
Oogenesis is a type of meiosis that produces eggs. Meiosis I of this process results in two daughter cells
known as the secondary oocyte and a small polar body. The polar body is formed by an unequal distribution of
cytoplasm during splitting of the primary oocyte. |
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Term
A form of asexual reproduction yielding progeny
without fertilization of the ova |
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Definition
Parthenogenesis is defined as the production of progeny without fertilization of the ova. Some insect
species such as the aphid utilize this reproduction method |
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Term
derived from the
mesoderm? |
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Definition
The ectodermal germ layers give rise to the epidermis of the skin and also the nervous system. The
endodermis, or endodermal germ layer, gives rise to the lining of the digestive system, its associated glands and
organs (such as the liver and pancreas), and the lungs. Most of the other organs and systems of the body are
mesodermal, including the excretory system, the reproductive system, the muscular and skeletal systems, and the circulatory system. Many of the human body tissues are derived from the mesoderm. |
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Term
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Definition
steroids and belong to a class of lipid-derived molecules with a characteristic ring structure. Steroid hormones
pass through the cell membrane with ease because they are lipid-soluble. |
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Term
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Definition
Carbohydrates, such as glucose and maltose, and proteins both yield 4 calories per gram consumed. Fats,
in contrast, are very high-energy, yielding 9 calories per gram consumed. |
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Term
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Definition
PGAL is generally considered the prime end-product of photosynthesis and it can be used as an immediate
food nutrient, combined and rearranged to form monosaccharide sugars, such as glucose, which can be
transported to other cells, or packaged for storage as insoluble polysaccharides such as starch. |
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Term
| During what stage of meiosis does crossing over occur? |
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Definition
During prophase I, the chromatin condenses into chromosomes, the spindle apparatus forms, and the
nucleoli and nuclear membrane disappear. Homologous chromosomes come together and intertwine in a
process called synapsis. Sometimes chromatids of homologous chromosomes break at corresponding points
and exchange equivalent pieces of DNA; this process is called crossing over. |
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Term
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Definition
homologous pairs align at the equatorial plane and each pair
attaches to a separate spindle fiber by its kinetochore. |
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Term
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Definition
the homologous pairs separate and are pulled to opposite poles
of the cell. This process is called disjunction and it accounts for a fundamental Mendelian law. |
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Term
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Definition
a nuclear membrane forms around each new nucleus. At this
point each chromosome still consist of sister chromatids joined at the centromere. The cell divides into two
daughter cells, each receiving a nucleus containing the haploid number of chromosomes. |
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Term
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Definition
| interkinesis is a short rest period between the two cell divisions of meiosis and during which the chromosomes partially uncoil |
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Term
| The blood group antigens are an example of |
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Definition
The blood group antigens are an example of codominance. Codominance occurs when multiple alleles
exist for a given gene, and more than one is dominant. When the genotype is heterozygous for codominant
alleles, the phenotype is the result of the expression of both alleles simultaneously. |
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Term
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Definition
| is the ability of a single gene to have multiple effects |
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Term
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Definition
Some progeny phenotypes are apparently blends of the parental phenotypes. This is
known as incomplete dominance. |
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Term
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Definition
is a phenomenon in which one gene alters the expression of another gene
that is independently inherited. |
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Term
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Definition
proportion of individuals who show the phenotype that is expected
from their genotype. One example of incomplete penetrance is a type of eye tumor called retinoblastoma, which
is due to a dominant allele. Not all individuals who inherit the allele develop the tumor. Furthermore, the severity
of the tumor varies among those individuals who show the retinoblastoma phenotype |
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Term
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Definition
such as hemophilia and color-blindness, are found on the X chromosome. In humans,
females have two X chromosomes and males have only one. As a result recessive genes that are carried on the
X chromosome will produce the recessive phenotypes whenever they occur in males, since no dominant allele is
present to mask them. The recessive phenotype will thus be much more frequently found in males |
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Term
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Definition
is a means of reproduction, while for multicellular organisms, it is a
method of growth, development, and replacement of worn-out cells.
process by which a cell doubles its organelles and
cytoplasm.
a cell replicates its DNA, then divides in two.
cell division can follow two different courses: mitosis and meiosis |
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Term
How many ATP are produced from 2 molecules of
glucose using only substrate level phosphorylation? |
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Definition
Substrate level phosphorylation occurs when ATP synthesis is directly coupled with theta degradation of
glucose without the participation of an intermediate molecule such as NAD+. Degradation of one glucose
molecule yields a net of 2 ATP from glycolysis and 1 ATP for each turn of the citric acid cycle. Thus a total of 4
ATP are produced by substrate level phosphorylation for one molecule of glucose. For two molecules, it would
be 8 ATP. |
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Term
| if you have 15% guanine, how much cytosine do you have? |
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Definition
If 15% are guanine, then another 15% must be cytosine. That leaves 70% to be adenine and thymine. One
half of the 70% is adenine (35%) and the other half is thymine (35%). |
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Term
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Definition
are the chief means of food storage in animals. They release more energy per gram weight than any
other class of biological compounds. They also provide insulation and protection against injury since they are a
major component of adipose tissue. |
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Term
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Definition
A quick and dirty method for analyzing pedigrees states that if a trait shows up in every generation and
shows no gender skewing, then it is probably an autosomal dominant trait.
If a trait skips generations and does not show gender skewing, it is probably an autosomal recessive. |
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Term
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Definition
| is one that results in cells that maintain the ability to develop into a complete organism. |
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Term
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Definition
results in cells whose future differentiation pathways
are determined at an early developmental stage. |
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Term
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Definition
begins when the morula develops a fluid-filled cavity called the
blastocoel, which by the fourth day becomes a hollow sphere of cells called the blastula. |
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Term
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Definition
Once implanted in the uterus, cell migrations transform the single cell layer of the
blastula into a three-layered structure called a gastrula. |
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Term
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Definition
An insertion or deletion of single nucleotide in the cell's DNA will cause a corresponding insertion or
deletion in the mRNA. Since mRNA is "read" by the ribosome three nucleotides at a time (3 nucleotides = a
codon), an addition or deletion will result in the shift in the codon reading frame, hence the term frameshift
mutation. |
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Term
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Definition
| when a nucleotide is replaced by an incorrect nucleotide. |
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Term
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Definition
the codon that results codes for the same amino acid, so the mutation has no effect, or is
"silent." This is because the genetic code is degenerate |
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Term
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Definition
| the resulting codon codes for a different amino acid (e.g. sickle cell anemia). |
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Term
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Definition
the resulting codon is a stop codon, and
translation is terminated prematurely. |
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Term
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Definition
are the antibodies that recognize the different blood types, and are so called because the
antibodies cause agglutination or clumping of blood. Agglutinogens are the antigens that determine blood type.
The agglutinogen is found on the surface of red blood cells, and there are two types involved. If a person has
the A agglutinogen they will make agglutinins to type B (anti-B). A type B person has the B agglutinogen and makes anti-A. A type AB person has both agglutinogens, so makes no agglutinins (otherwise that person will
coagulate their own blood). Type O blood has neither the A or B agglutinogen on the surface of the RBCs, but
has agglutinins to both type A and type B. Rh factor (named after the creature it was first studied in-the rhesus
monkey) is another RBC agglutinogen and is completely independent of the ABO types. |
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Term
| chromosomes go from single stranded to double stranded when? |
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Definition
| the replicate during the S (synthesis) phase of interphase. |
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Term
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Definition
Primary structure is the unique sequence of amino acids. Tertiary structure involves interactions between
various kinds of side chains of amino acids. Quaternary structure involves the interaction of two or more
polypeptides. Secondary structure is the repetitious twisting or folding of the polypeptide backbone; including
both α helices and β pleated sheets. |
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Term
| where did chloroplasts come from? |
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Definition
Chloroplasts are thought to have descended from free living prokaryotic autotrophs that first invaded cells
and over time developed a symbiotic relationship with the host cell. Further selection and evolution resulted in
the autotroph losing it's ability to live outside of the host cell and in time became another organelle. The fact that
chloroplasts contain their own DNA and ribosomes (which resemble prokaryotic ribosomes, not eukaryotic) and
replicate independently provide further evidence to this theory. Mitochondria are thought to have evolved from
free living prokaryotic heterotrophs, thus eliminating choices A and B. Red algae are eukaryotic autotrophs that
have chloroplasts similar to other algae, so they must have descended from the same evolutionary line as
discussed above. |
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Term
How many genetically different gametes can be formed
by a mouse that is genotypically AABbCc? (Assume no
linkage between these genes and that none are lethal.) |
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Definition
The gametes that can form from an AABbCc mouse are: ABC, ABc, AbC, and Abc. Therefore the correct
answer is four. Alternatively, using the formula 2n, where n = # of heterozygous genes, n = 2, and 22 = 4. |
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Term
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Definition
[image]
is defined as the use of energy to move a substance across a membrane against a
concentration gradient |
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Term
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Definition
[image]
involves carriers, channels, or direct diffusion through a membrane. |
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Term
| Which of the following cells does not have DNA? |
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Definition
A. Phagocyte
B. Epithelial cell
C. Erythrocyte
D. Paramecium
E. Sperm
All of the cells have genetic material with the exception of the erythrocyte, a biconcave disk-shaped cell that
contains hemoglobin and has no nucleus. |
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Term
Continuous muscle contraction causes a buildup of lactic
acid because |
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Definition
Continuous muscle contraction utilizes all the available oxygen, and causes the muscle fiber to depend on
anaerobic respiration for energy. NAD+ must be regenerated for glycolysis to continue in the absence of O2.
This is accomplished by reducing pyruvate into lactic acid and only produces two ATP per glucose. |
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Term
What is the major difference between prokaryotes and
eukaryotes? |
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Definition
Prokaryotes are unicellular organisms with a simple cell structure. They have an outer cell membrane but
do not contain any membrane-bound organelles. There is no true nucleus; the genetic material consists of a
single circular molecule of DNA concentrated in an area of the cell called the nucleoid region. They have a cell
wall, a cell membrane, cytoplasm, ribosomes (different from those found in eukaryotes), and sometimes flagella.
Eukaryotes are bounded by cell membranes and contain cytoplasm. Cytoplasm contains organelles suspended
in a semifluid medium called the cytosol. The genetic material consists of linear strands of DNA organized into
chromosomes and located within a membrane-enclosed organelle called the nucleus. |
|
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Term
| where would you find cristae? |
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Definition
Mitochondria are the sites of aerobic respiration within the cell and hence the suppliers of energy. Each
mitochondrion is bound by an outer and an inner phospholipid bilayer membrane. The outer membrane is
smooth and acts as a sieve, allowing molecules through on the basis of size. The area between the inner and
outer membranes is known as the intermembrane space. The inner membrane has many convolutions called
cristae and a high protein content that includes the proteins of the electron transport chain. The area bounded
by the inner membrane is known as the mitochondrial matrix and is the site of many of the reactions in cell
respiration. Mitochondria are different from the other organelles in that they are semiautonomous; that is, they
contain their own circular DNA and ribosomes, which enable them to produce some of their own proteins and to
self-replicate by binary fission. |
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Term
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Definition
The Hardy-Weinberg law states that gene ratios and allelic frequencies remain constant through the
generations in a nonevolving population. Four criteria must be met for this to occur: 1. Random mating; 2. a
large population; 3. no migration into or out of the population; and 4. a lack of mutation. If all four of these are
met, the gene frequencies will remain constant. Anytime all four of these are not met, the gene frequencies will
change and evolution may occur. |
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