Unit 1 The Study of Life
Assignment 1: Course Overview
No Definitions
Unit 1 The Study of Life
Assignment 2: What is Life?
cell the basic unit of life
DNA a giant molecule consisting of the sugar deoxyribose, phosphates, and
nitrogen bases; contains the coded genetic information
homeostasis the maintenance of a constant internal body environment by an
organism's body
metabolism all of the chemical reactions in the organism for maintenance of the
processes of life
organelle a small structure within the cell that serves specialized functions
Unit 1 The Study of Life
Assignment 3: Introduction Into Biology
ecology the study of living things' dependence on each other and their
environment; the relationship of an organism with its total environment
phenotypic cure the alteration of the phenotypic expression of a genetic defect
Unit 1 The Study of Life
Assignment 4: Scientific Inquiry
hypothesis an educated guess or rational explanation about a specific phenomenon
law a universal and absolute fact or truth about a specific action or
phenomenon
photosynthesis a process in green plants that involves the use of carbon dioxide and
water in the production of glucose and oxygen using the Sun's energy
science Body of factual knowledge that exists around the world, and the method
of study used to arrive at that knowledge
scientific method a recognized means of inquiry to provide scientific answers to questions
theory an explanation for a natural phenomenon that appears to be supported by
evidence gathered over a period of time
Unit 1 The Study of Life
Assignment 5: The Scientific Method
controlled experiment the testing of a hypothesis in duplicate with only one factor being
different
hypothesis an educated guess or rational explanation about a specific
phenomenon
scientific method a recognized means of inquiry to provide scientific answers to
questions
theory an explanation for a natural phenomenon that appears to be
supported by evidence gathered over a period of time
Unit 1 The Study of Life
Assignment 6: Laboratory Safety
eye wash station this is used when a chemical splash or gas fume has reached the eyes.
fire blanket a blanket used to smother small fires.
fire extinguisher used to put out small fires in the lab.
first aid kit kit used for any small cuts or injuries that occur in the lab.
lab shower the shower is used when a chemical spill has occurred on clothes or in
case of a fire.
ventilation hood a workstation that shields the user from any toxic or dangerous fumes
and vents the substance away.
Unit 1 The Study of Life
Assignment 7: Introduction to Taxonomy
class a taxonomic category containing a group of similar orders; between order
and division in plant classification; between order and phylum in animal classification
classification a system of distinguishing groups for purposes of identification; a means
or device for sorting into groups with similar characteristics
division in plant classification, a grouping of similar classes; between kingdom and
class in taxa
domain the largest taxonomic category
family a taxonomic category containing a group of similar genera; between the
taxa of order and genus
genus
a taxonomic category containing a group of similar species; between the taxa of family and species; the first name of the scientific name; (plural, genera)
kingdom a taxonomic category containing a group of similar phylums; between the
taxa of domain and phylum
order a taxonomic category containing a group of similar families; between the
taxa of class and family
phylum a grouping of similar classes; a taxonomic category between kingdom and
class; (plural, phyla)
species the smallest taxonomic category, containing only similar varieties of an
organism; the second word of the scientific name
taxon the categories used in classifying organisms (i.e., class, order); (plural,
taxa)
taxonomist a scientist who classifies organisms
taxonomy the science of the classification of organisms
Unit 1 The Study of Life
Assignment 8: Taxonomy: Classification and Naming
archaea also known as archaebacteria; prokaryotic organisms with
different structures than bacteria; believed to be the most primitive organisms, capable of inhabiting extreme environments
binomial nomenclature the two-name system of naming living things used in classification
eubacteria prokaryotic organisms including bacteria and cyanobacteria
eukaryote a cell that has a membrane-bound nucleus and/or organelles as its major
characteristic
morphology the form or appearance of an organism; the collection of physical
characteristics and the structure which make up an organism; a basis for
species definition
prokaryote a cell whose nucleus is not bound by a membrane
reproductive isolation the separation of populations of organisms by some type of barrier
to produce variations of species; no reproduction or exchange of genes occurs between the separated groups; a basis for species definition
Unit 1 The Study of Life
Assignment 9: Keys to Classification
characteristic feature that identifies and distinguishes one living thing from another
dichotomous key a two-choice sorting device used in taxonomy to identify taxa, genus
species, or common names of plant or animal specimens
key a sorting device made up of a system of choices, as used in taxonomy
systematics the study of classifying organisms according to their evolutionary
relationships
Unit 2 Biochemistry
Assignment 1: Life Chemistry
biochemistry the study of energy and matter within living organisms
Unit 2 Biochemistry
Assignment 2: Atoms, Elements, and Compounds
atom the smallest unit of an element that still retains the chemical properties of
the element
atomic mass the mass of an element; approximately equal to the number of protons
and neutrons in an atom's nucleus
atomic number the number of protons in the nucleus of the atom; also the number of
electrons around the nucleus
atomic weight the average relative mass of each element
compound a chemical substance composed of atoms of two or more elements
chemically bonded to one another
diatomic containing two atoms
electron a subatomic particle fundamental to all matter, existing in orbit around the
nucleus of an atom, and carrying a negative charge
elements substances made up of only one type of atom
molecule The smallest unit of a pure substance that consists of two or more atoms
held together by a chemical bond.
neutron a subatomic particle, fundamental to all matter except hydrogen, that
exists in the nucleus and has about the same mass as a proton (but carries no charge)
nucleus the positively charged center of an atom that contains both the protons
and neutrons of the atom
proton a subatomic particle fundamental to all matter, existing in the nucleus,
having a positive charge, and about equal in mass to a neutron
shell the path surrounding the nucleus of an atom in which electrons are
normally located
Unit 2 Biochemistry
Assignment 3: Chemical Bonds
anion a negatively charged ion; an atom that has gained an electron
cation a positively charged ion; an atom that has lost an electron
chemical bond combining of atoms through the interaction of their electrons in the
outermost orbit
chemical reaction when the atoms of elements or compounds interact to form at least one
new compound
covalent bond a chemical bond formed between two atoms through the sharing of
electrons
hydrogen bond an intermolecular force (attraction) occurring between a hydrogen atom
and fluorine, oxygen, and nitrogen atoms.
ion an electrically charged atom or group of atoms formed by the loss or gain
of electrons
ionic bond a bond formed by the electrical attraction between two oppositely charged
Ions
octet rule rule that states that an atom with an unfilled outer shell will interact with
other atoms to complete its shell
valence the number of electrons an element must gain or lose in order to complete
its outer electron shell
Unit 2 Biochemistry
Assignment 4: Chemical Reactions
activation energy the energy required to start a chemical reaction
adenosine triphosphate a molecule produced during glucose breakdown; serves as an
energy source for the cell
buffer a substance that will resist changes in pH within reasonable limits
chemical equilibrium when a reversible reaction is occurring in both directions at the
same rate (products and reactants do not change in concentration)
decomposition reaction a chemical reaction in which the compound is broken into its
constituent parts
exchange reaction a chemical reaction in which the substrates trade constituent parts
law of mass action the condition whereby the concentration of reactant product influences
the rate and net direction of a reversible chemical reaction
metabolism all of the chemical reactions in an organism required for maintenance of
the processes of life
pH a measure of the hydrogen ion concentration in a solution
reversible reaction a chemical reaction in which the reactants used to form the products can
also be formed from the products
synthesis reaction a chemical reaction in which two or more units are added together to form
a new compound
Unit 2 Biochemistry
Assignment 5: Chemistry of Water
adhesion molecular attraction of dissimilar molecules, usually due to hydrogen
bonding
cohesion molecular attraction of similar molecules, usually due to hydrogen
bonding
hydrogen bond a weak chemical bond formed when a hydrogen atom is shared by two
adjacent molecules
inorganic a chemical compound that doesn't contain carbon
organic a chemical compound that contains carbon
polar molecule a molecule that has partial positive and negative charges at each end
solute a substance that is dissolved in a liquid
solvent a liquid that acts to dissolve or suspend solutes
specific heat the amount of energy required to change 1 gram of substance by 1°C
Unit 2 Biochemistry
Assignment 6: Acids, Bases, and pH
alkaline a base solution; has a pH of more than 7
ionization the process that creates positive and negative ions
pH a measure of the hydrogen ion concentration in a solution
salt the compound formed by the ionic bonding of a cation and anion
Unit 2 Biochemistry
Assignment 7: Carbon of Life
carbohydrate a sugar or polymer of sugar; contains the elements carbon, hydrogen,
and oxygen
functional groups a group of atoms with distinct chemical properties
hydrolysis the breakdown of large molecules into smaller molecules with water being
a reactant
lipid a group of organic compounds including fats, steroids, and phospholipids
nucleic acid a sequence of sugars, phosphates, and nitrogenous organic bases—DNA
and RNA
polymer a chemical compound in which each molecule is made up of two or more
simpler molecules strung together
polymerization a reaction in which two or more molecules unite, forming a more complex
molecule
protein a large, complex organic molecule consisting of a large number of amino
acids linked together by peptide bonds
Unit 2 Biochemistry
Assignment 8: Carbohydrates and Lipids
carbohydrate a sugar or polymer of sugar; contains the elements carbon, hydrogen,
and oxygen
dehydration synthesis a bonding of subunits to form a polymer by the loss of
water
disaccharide a two-sugar polymer
enzyme a protein molecule which is specialized to speed up a specific chemical
reaction in biological systems
glucose a simple sugar (C 6H 12O 6) occurring in plant and animal tissues
hormone a chemical synthesized by an organism; aids in the control of a specific
function in the organism
hydrolysis the breakdown of large molecules into smaller molecules with water being
a reactant
lipid a group of organic compounds including fats, steroids, and phospholipids
macromolecules large molecules containing thousands of atoms and many functional
groups
monosaccharide the building block unit of carbohydrates; a simple sugar
polysaccharide a polymer of simple sugars (monosaccharides)
Unit 2 Biochemistry
Assignment 9: Proteins, Enzymes, and Nucleic Acids
amino acid the basic building block of proteins; contains a carboxyl group
(-COOH) and an amino group (-NH 2)
catalyst any substance that accelerates a chemical reaction without
being used up in the reaction
DNA (deoxyribonucleic acid) a complex molecule containing the
genetic code
enzyme a protein molecule that is specialized to speed up a specific
chemical reaction in biological systems
nucleic acid a sequence of sugars, phosphates, and nitrogenous organic
bases—DNA and RNA
protein a large, complex organic molecule consisting of a large
number of amino acids linked together by peptide bonds
RNA (ribonucleic acid) a nucleic acid that participates in the
synthesis of proteins
substrate a compound that is involved in a chemical reaction and is
chemically changed by the reaction
Unit 2 Biochemistry
Assignment 10: Nutrition
carbohydrates Organic compounds that contain carbon, hydrogen and oxygen
and are the main source of energy for the body.
enzymes Proteins that help drive the chemical reactions that occur in the body.
lipids Fats, oils, and waxes that are insoluble in water.
metabolism The conversion of the energy found in foods into a usable form of energy
for the body.
minerals Inorganic substances found in foods needed for growth, regulation and
Development.
proteins Organic compounds composed of amino acids that form the structure of
the body.
vitamins Organic substances found in foods that aid enzymes.
Unit 3 Cells
Assignment 1: Cell Theory
cell the basic building block of all forms of life
cell theory the idea of Schleiden and Schwann that the basic unit of life is the cell
and that all living organisms are composed of cells
organismal theory theory that states that the basic unit of life is the organism itself, which
may be divided into cells for efficiency
resolving power the ability to clearly distinguish between two objects
Unit 3 Cells
Assignment 2: Cell Overview
cell the basic building block of all forms of life
cell wall the rigid wall that surrounds the cell membrane of plant cells
chloroplast the tiny body that contains chlorophyll; part of the cell in which
photosynthesis takes place
cytoplasm the living substance of a cell, excluding the nucleus
eukaryote a cell that has a membrane-bound nucleus and/or organelles as its major
characteristic
membrane a protein and fat structure serving as a covering and enclosure for cells
nucleolus small, dark structure within the nucleus of a cell; thought to make r-RNA
to construct the ribosomes
nucleus the protoplasmic substance separate from the cytoplasm; the cell
headquarters or information center; location of DNA and RNA; contains
chromosomes and the nucleolus; (pl.nuclei)
organ a group of tissues working together as a unit for a particular purpose in
the body
organelle a small structure within the cell that serves specialized functions
prokaryote a cell whose nucleus is not bound by a membrane
protoplasm the organic substance making up the cells of all living things
specialization limiting a cell to a specific function
system a group of organs working together for a common purpose
tissue a group of cells working together to perform a particular task
vacuole a cell storage body that increases in size with age; included within, but not
a part of the cytoplasm; often stores water and poisonous by-products of
cell activities
virus differs from a cell and consists of a nucleic acid (RNA or DNA) in a protein
coat
Unit 3 Cells
Assignment 3: Cell Structures and Functions
cell wall the rigid wall that surrounds the cell membrane of plant cells
centriole a rod-shaped structure on the side of an animal cell nucleus;
thought to play a role in the formation of the spindle during cell division
chlorophyll a green pigment in plants that serves to trap the Sun's energy
for photosynthesis
chloroplast the tiny body that contains chlorophyll; part of the cell in which
photosynthesis takes place
cytokinesis the part of the cell division that causes the separation of the
cytoplasm
cytoplasm the living substance of a cell, excluding the nucleus
cytoskeleton protein fibers that provide support and shape for the cell
endoplasmic reticulum a series of tubes in the cytoplasm of a cell that
are believed to be used as channels for transporting molecules within the cell
enzyme a protein molecule that is specialized to speed up a specific
chemical reaction in biological systems
flagella whip-like cell extensions that give the cell motility
Golgi body a flattened sac within the cytoplasm of the cell; an extension of
the endoplasmic reticulum; involved in producing and
packaging secretions
lysosome packets within the cell cytoplasm that contain digestive
enzymes
mitochondria structures within the cell cytoplasm responsible for the
production of energy and the storage of energy in ATP
nucleolus small, dark structure within the nucleus of a cell; thought to
make r-RNA to construct the ribosomes
Unit 3 Cells
Assignment 3: Cell Structures and Functions (continued)
nucleus the protoplasmic substance separate from the cytoplasm; the
cell headquarters or information center; location of DNA and RNA; contains chromosomes and the nucleolus
organelle a small structure within the cell that serves specialized
functions
osmosis the diffusion of water across a semipermeable membrane
peroxisome packets within the cell cytoplasm that contain powerful
enzymes
plasma membrane the semipermeable membrane surrounding human and
animal cells; made of phospholipids and proteins
plastid tiny sacs in the cell that may either contain starch or oils as
stored food or a plant pigment
protoplasm the organic substance making up the cells of all living things
ribosome tiny, dot-like bodies in the cytoplasm or on the endoplasmic
reticulum; important in protein synthesis
spindle the fibers that direct the even distribution of chromosomes to
each daughter cell during nuclear division
vacuole a cell storage body that increases in size with age; included
within, but not a part of the cytoplasm; often stores water and poisonous by-products of cell activities
vesicle sacs containing protein produced by the endoplasmic
reticulum
Unit 3 Cells
Assignment 4: The Plasma Membrane
adenosine triphosphate the high energy chemical compound with three
phosphate groups that provides energy for all other cell activities; (ATP)
cellular respiration chemical reactions in plants and animals that break down food molecules
into energy (ATP)
diffusion movement of particles or molecules from higher concentration to lower
concentration
endocytosis when cells engulf or ingest substances
exocytosis when cells expel or get rid of substances from within
homeostasis the relatively constant state in the internal environment of an organism
hypertonic a solution that has a higher salt concentration than the salt concentration
inside the cells
hypotonic a solution that has a lower salt concentration than the salt concentration
inside the cells
isotonic a solution with the same salt concentration as the salt concentration
inside the cells
osmosis the diffusion of water across a semipermeable membrane
phagocytosis when cells eat other cells or large substances
phospholipid a molecule with polar and nonpolar ends that, along with protein, makes
up the plasma membrane
pinocytosis when cells eat small or dissolved substances
polar molecule a molecule that has partial positive and negative charges at each end
protein a large, complex organic molecule consisting of a large number of amino
acids linked together by peptide bonds
Unit 3 Cells
Assignment 5: Cell Regulation
cellular level a degree of organism complexity; either unicellular or colonial
homeostasis the relatively constant state in the internal environment of an organism
feedback loops self-regulation mechanisms that send information to appropriate
physiological systems so that appropriate adjustments can be made
negative feedback a control mechanism that inhibits or counteracts an earlier reaction
positive feedback a control mechanism that intensifies or enhances an earlier reaction
system level a degree of organism complexity; cells arranged into systems
Unit 4 Cell Energy
Assignment 1: Laws of Thermodynamics
entropy the energy lost to disorder
kinetic related to or possessing motion
metabolism all of the chemical reactions in an organism required for maintenance of
the processes of life
potential possible; ability to go into action or perform work
thermodynamics the study of energy and its transformations
Unit 4 Cell Energy
Assignment 2: Energy Transformations
activators chemical mechanisms that activate or start a reaction
dephosphorylation when a phosphate is removed from a molecule; when a phosphate from
ATP is removed to make ADP and a free phosphate molecule
inhibitors chemical mechanisms that prevent something from occurring
metabolic pathways a chain of enzyme reactions within cells that break down or build
molecules
metabolism all of the chemical reactions in an organism required for maintenance of
the processes of life
oxidation a chemical reaction in which oxygen is combined with another substance
phosphorylation when a phosphate is added to a molecule; when a phosphate is added to
ADP to make ATP
Unit 4 Cell Energy
Assignment 3: Photosynthesis: Energy Production in Plants
autotroph an organism that can make its own food
Calvin cycle the dark reaction process of photosynthesis that uses carbon dioxide for
the synthesis of carbohydrates
carotenoid pigment a pigment ranging in color from yellow to red; helpful in capturing the
Sun's light energy for use in photosynthesis
chlorophyll a green pigment in plants that serves to trap the Sun's energy for
photosynthesis
chloroplast the tiny body that contains chlorophyll; part of the cell in which
photosynthesis takes place
photosynthesis a process that involves the use of carbon dioxide and water in the
production of glucose and oxygen using the Sun's energy
radiation transfer of heat or energy through rays of various wavelengths
Unit 4 Cell Energy
Assignment 4: Cellular Respiration: Anaerobic Phase
aerobic occurring in the presence of oxygen
alcohol fermentation the stage of respiration that occurs in anaerobic conditions in less
complex organisms
anaerobic occurring in the absence of oxygen
glycolysis process that involves the first step in the chemical breakdown of glucose;
converting glucose to pyruvic acid
lactic acid fermentation the stage of respiration that occurs in anaerobic conditions in
animal cells
Unit 4 Cell Energy
Assignment 4: Cellular Respiration: Aerobic Phase
aerobic occurring in the presence of oxygen
anaerobic occurring in the absence of oxygen
assimilation cell activities associated with the utilization of food molecules and energy
in life processes
cellular respiration a series of chemical reactions that break down sugars and produce
energy
electron transport chain process that involves the third step in the chemical breakdown of
glucose; transferring electrons to form ATP
glycolysis process that involves the first step in the chemical breakdown of glucose;
converting glucose to pyruvic acid
Krebs cycle process that involves the second step in the chemical breakdown of
glucose; converting pyruvic acid into carbon dioxide
Unit 4 Cell Energy
Assignment 4: Energy Flow in Ecosystems
decomposers bacteria and fungi that break down dead matter
ecosystem the basic relationships that show how a community of plants, animals,
and bacteria live and grow and how these living things are dependent on
each other as well as the Sun, soil, and other nonliving parts of their
environment; a cycle of relationships
food chain line of plants and animals that shows the order in which organisms are
eaten
food web a diagram that shows the connections among food chains in an
ecosystem
primary consumer organisms that eat producers
secondary consumer organisms that eat primary consumers
tertiary consumer predator that eats secondary consumers
trophic level feeding level within an ecosystem
Unit 5 Cell Division and Reproduction
Assignment 1: Types of Reproduction
angiosperm flower-bearing plant
anisogamy the condition of having anisogametes—gametes similar in shape but
different in size
asexual reproduction the replication of a parent cell or organism, producing a genetically
identical offspring
cytokinesis the part of the cell division that causes the separation of the cytoplasm
fertilization the fusion of gametes to produce a new cell or zygote; often said to be
the union of egg and sperm
gametangium (pl. gametangia) an organ of lower plants, some protists and some
fungi, that produces gametes
gamete the reproductive cell in sexual reproduction—for example, the egg or
sperm
gonad gamete-producing organ in animals
gymnosperm cone-bearing plant; often called evergreen
isogamy the condition of having isogametes—gametes of the same size and shape
meiosis the process involving the division of the nucleus in a reproductive cell;
responsible for genetic recombination
mitosis the process involving the division of the nucleus of a body cell
oogamy the condition of having oogametes—gametes of different sizes and
shapes; usually have eggs and sperm
ovum (pl. ova) the egg cell; a female gamete
sexual reproduction the form of production of new individuals by two parents in which
the offspring obtains half of its hereditary information from each parent
sperm a small, flagellated male gamete that swims to the egg to fertilize it
Unit 5 Cell Division and Reproduction
Assignment 2: Fertilization
conjugation an act of fertilization involving the transfer of cell contents to another cell;
usually occurs in simpler organisms
diploid having chromosomes in homologous pairs
external fertilization a type of mating pattern in which eggs and sperm are released
into the water after the mating partners come near one another; occurs outside the body of the female
fertilization the fusion of gametes to produce a new cell or zygote; often said to be
the union of egg and sperm
haploid having a single, complete set of chromosomes, or one half of each pair of
homologous chromosomes
homologous chromosomes chromosomes that are the same in size and shape and
control the same characteristics; occur in pairs in higher animals and plants
internal fertilization a mating pattern in which the male and female come close together, the
male introduces the sperm into the body of the female, and fertilization occurs
pollination transfer of pollen from male to female cones in gymnosperms, or from
anther to stigma in flowering plants
zygote the result of fertilization in which two gametes have fused together; often
simply called a fertilized egg
Unit 5 Cell Division and Reproduction
Assignment 3: Cell Division: Fission
binary fission asexual reproduction in which a single cell divides into two with no
exchange of genetic material; reproduction method of bacteria
budding asexual reproduction involving the growth of a new individual from part of
an older organism; uneven distribution of cytoplasm that results in one
cell receiving most of the cell contents
colony a group of organisms attached to one another after undergoing asexual
reproduction from a common parent
cytokinesis the part of the cell division that causes the separation of the cytoplasm
fragmentation a phenomenon in which organisms break into two or more parts and then
each part grows into a new individual
mitosis the process involving the division of the nucleus of a body cell
multiple fission asexual reproduction in which a single cell undergoes many mitotic
divisions in the nucleus and a number of daughter cells are produced all at once
Unit 5 Cell Division and Reproduction
Assignment 4: Cell Division: Mitosis
anaphase the stage of mitosis in which the chromosomes move to opposite ends of
the cell
cell plate a structure that forms across the middle of a higher plant cell in telophase;
the beginning of a new cell wall which divides the two daughter cells from one another to finish mitosis
centriole forms the ends of the spindle fibers in the cell during mitosis; normally
found in animal cells
centromere part of a chromosome that attaches to the spindle apparatus during
mitosis or meiosis
chromatin material in the cell nucleus that carries hereditary information; made up of
DNA and various kinds of protein
cleavage furrow a structure that forms around animal cells in telophase; a constriction in
the middle of the parent cell that remains until the two halves of the cell
divide into two, new daughter cells to finish mitosis
daughter cell the cell produced as a result of cell division
interphase period between two periods of mitosis
metaphase the phase of mitosis in which the daughter chromosomes line up across
the middle of the cell
mitosis the process involving the division of the nucleus of a body cell
parent cell the cell that begins the process of cell division
prophase the first part of mitosis in which the chromosomes shorten and thicken,
the nucleolus breaks down, and the nuclear envelope disintegrates
sister chromatids two rod-like strands replicated by a chromosome during interphase;
becomes a daughter chromosome by the end of cell division
spindle apparatus a system of fibers stretching from one end of a mitotic cell to the other
telophase the phase of mitosis in which the daughter chromosomes have reached
opposite ends of the cell, the nuclear envelope and nucleolus reform, and
the process of cytokinesis begins
Unit 5 Cell Division and Reproduction
Assignment 5: Cell Division: Meiosis
anaphase I the stage on the first meiotic division in which sister chromatids of a
chromosome split and migrate to opposite poles
anaphase II the stage in the second meiotic division in which sister chromatids of a
chromosome split and migrate to opposite poles
crossing over a condition in which non-sister chromatids of homologous chromosomes
exchange genes
diploid having chromosomes in homologous pairs
haploid having a single, complete set of chromosomes, or one half of each pair of
homologous chromosomes
homologous pair pair of identical chromosomes (chromosomes that contain the same
genes) from each parent, which all organisms produced by sexual reproduction receive
interphase period between two periods of mitosis
meiosis the process involving the division of the nucleus in a reproductive cell; cell
division in which the daughter cells have fewer chromosomes than the parent cell; responsible for genetic recombination
metaphase I the stage in the first meiotic division in which the homologous
chromosomes line up as a pair, forming a tetrad of chromatids at the
equator of the cell
metaphase II the stage in the second meiotic division in which the chromatid pair lines
up at the equator of the cell
M phase a period in the life of the cell when it is conducting cell division
prophase I the stage in the first meiotic division in which the doubled chromosomes
become visible and the nuclear membrane disappears
prophase II the stage in the second meiotic division in which the chromatid pair
becomes visible and the nuclear membrane disappears
synapsis the meiotic process in prophase I in which the tetrads line up side-by-side;
initiates the crossing over process
telophase I the stage of the first meiotic division when the cell divides into two cells,
each containing one member of each pair of homologous chromosomes
telophase II the stage of the second meiotic division when the cell divides into two
haploid cells that become the gametes
tetrad during prophase I, when the two pairs of chromatids of the homologous
pair of chromosomes come together to form a four chromatid unit; time when crossing-over can occur
Unit 5 Cell Division and Reproduction
Assignment 6: Cycle and Regulation
G 0 phase period during the life of a cell when it has finished mitotic division
G 1 phase period during the life of a cell between the end of mitosis and the
synthesis of more genetic material for another mitotic division
G 2 phase period during interphase between the synthesis of new genetic material
and the beginning of mitosis
interphase period between two periods of mitosis
M phase a period in the life of the cell when it is conducting cell division
S phase the period of interphase when the genetic information is being duplicated
Unit 5 Cell Division and Reproduction
Assignment 7: Cell Differentiation
differentiation the maturation of a cell for a specific function
elongation in the maturation process of cells, the first step after production by a
meristem; a lengthening of the cell assisted by water intake in living
things; an organic catalyst
G 0 phase period during the life of a cell when it has finished mitotic division
meristem the youthful, undifferentiated cells of root and shoot tips and other plant
parts that produce new cells for growth in size and girth