The document provides definitions for various biological terms: 1. It defines key terms related to cellular processes like diffusion, photosynthesis, protein synthesis, and sexual reproduction. 2. It also defines broader biological concepts including biodiversity, the circulatory system, nutrition, and pH. 3. The document acts as a reference for scientific terms across multiple levels of biological organization from cells and organelles to whole organisms and ecosystems.

1. Absorption 2n
The diffusion of small molecules Diploid; the normal number of
into cell. chromosomes for the species.
In humans the 2n number is 46.
acid rain amino acid
The result of atmospheric moisture The basic building block of proteins.
in the air mixing with emissions They contain an amine group
containing oxides of sulfur and and a carboxyl group.
nitrogen

2. Amniocentesis Antibiotic
A procedure that removes amniotic A substance that kills bacteria.
fluid containing fetal cells for
analysis to determine the
presence of genetic defects.
Autotroph Bacteria
An organism that can use the A group of monerans, mostly
heterotrophs, that can have either a
energy from the sun or chemical
round, rod or spiral shape. Some
reactions to make organic are disease-producing; many are
nutrients from inorganic decomposers.
materials.

3. Benedict's solution biological control
A reagent used to test for simple The use of biological methods of
sugars. If the test is positive, the pest control such as species
solution turns brick red or green. specific sex lures or natural
parasites.
carbohydrate catalyst
An organic nutrient made of carbon, A chemical that speeds up the rate
hydrogen and oxygen and a of a chemical reaction but is not
primary fuel in cellular used up.
respiration

4. cell membrane cell wall
The semi-permeable outer The rigid porous structure that
boundary of the cell. It is made surrounds the cells of plants and
of lipids and protein. some microorganisms.
chromosome circulation
A structure found in the nucleus The transport of materials within a
that is made of DNA and cell or between parts of a
protein. It contains the multicellular organism.
hereditary information.

5. cleavage cloning
The first mitotic divisions of the The production of genetically
zygote. There is an increase in identically organisms.
the number of cells but a
decrease in size of the
individual cells.
codon competition
A sequence of three nitrogenous The struggle that results when
bases in the messenger RNA more than one species has the
sequence that are specific for same requirements for survival.
one amino acid.

6. consumer crossing-over
A heterotroph; an organism that The equal exchange of genetic
cannot make its own food and material by homologous
must ingest (eat) organic chromosomes during the
nutrients. synapsis of meiosis.
Cystic fibrosis (CF) cytoplasm
An inherited disease in which a The fluid found between the
defective gene causes the body to
nucleus and the cell membrane.
produce an abnormally thick mucus
that clogs the lungs and leads to
life-threatening lung infections.

7. Darwin deforestation
The scientist who developed the The removal or destruction of a
evolutionary theory of natural forest by cutting down or
selection. burning the trees without
replacing them.
denaturation Deoxygenated
Deoxygenated
A change in the structure of a protein State of blood when it is returning
molecule due to high temperatures to the heart via veins, except
or other factors. The change in
the pulmonary veins.
shape causes the protein to lose the
ability to function.

8. digestion disaccharide
The enzyme controlled process that A molecule made of two
changes large insoluble monosaccharides.
molecules into small soluble
molecules.
double helix ecology
The shape of the DNA molecule, The study of the interactions of
the spiral shape formed by the living things and their
parallel strands. environment.

9. endocrine system estrogen
The specialized ductless glands A hormone secreted by the ovaries
which secrete hormones that which aids in the control of the
are responsible for regulating menstrual cycle and promotes the
bodily activities. development of the female
secondary sexual characteristics.
extinction fallopian tubes / Oviduct
The destruction of all members of a The oviducts of placental
particular species. mammals. The tubes that carry
the egg from the ovary to the
uterus.

10. fatty acid feedback
An organic molecule that contains A mechanism that responds to
the carboxyl (-COOH) group change by causing a response.
attached to a carbon chain. It is
one of the building blocks of
lipids.
food chain Fungi
A series of organisms, starting with A kingdom which contains
a producer, through which food multicellular plantlike organisms
energy is passed in an that lack chlorophyl and so are
ecosystem. not photosynthetic.

11. gametes gastrulation
Monoploid sex cells produced in The process by which one side of
gonads by meiotic cell division. the blastula pushes in to form a
Sperm and egg. two-layered gastrula.
genetic engineering global warming
The process which transfers genes A condition that occurs when
to another organisms DNA carbon dioxide in the
resulting in recombinant DNA. atmosphere absorbs heat
radiated from the earth's
surface.

12. glucose growth
A monosaccharide that is the primary
An increase the size or the number
source of cellular energy in most
organisms. It is one of the basic of cells in an organism.
building blocks of polysaccharide
carbohydrates.
habitat heredity
The portion of the environment in The sum total of genetically
which an organism exists. inherited characteristics which
are passed from parents to
offspring.

13. heterotroph homeostasis
An organism that cannot make its The maintenance of a stable
own food and therefore must internal environment.
ingest (eat) organic nutrients.
hybrid hydrolysis
Heterozygous. The pair of genes An enzyme-controlled reaction in
for a trait are not alike, for which large insoluble molecules
example Tt. are broken down into small
soluble molecules when water is
added; digestion.

14. indicator internal fertilization
A substance that changes color to The fertilization of the egg inside
show that a particular chemical the body of the female.
is present or that a reaction has
occurred.
intestine iodine
A specialized section of the An element that is needed for the
alimentary canal where proper functioning of the thyroid.
digestion and absorption takes
place.

15. large intestine leukemia
A section of the digestive tube A type of cancer which produced
where water is reabsorbed from large numbers of non-functional
the undigestable material. white blood cells.
limiting factor lymph
A nonliving, physical factor that The intercellular fluid (ICF) found in
limits the type of organisms that the lymphatic vessels.
can exist in a particular
ecosystem.

16. menstrual cycle mesoderm
The hormone-controlled cycle The germ layer located between
during which the egg matures the endoderm and the
and is released, and the uterine ectoderm.
lining prepares to receive it.
metabolic wastes microorganism
The wastes produced as a result of Any organism that is so small that it
metabolism, including carbon can only be seen by using a
dioxide, water, nitrogenous microscope.
wastes and salts.

17. mitosis, mitotic cell division Monera
Cell division which results in two A kingdom which contains simple
cells each containing the diploid organisms that lack an
(2n) number of chromosomes. organized nucleus (prokaryotic),
such as blue green algae and
bacteria.
multicellular mutation
Composed of many cells. A change in the genetic material.

18. natural selection nephron
Darwin's evolutionary theory that states that
there are variations in organisms that will The functional unit of the human
make some organisms better fitted for kidney. These microscopic
survival than others. Those organisms structures filter wastes from the
survive, reproduce and pass those
variations on to their offspring.
blood.
nervous system neurotramsmitter
A system which allows an organism A chemical released into the
to respond to stimuli; the neuron synapse by the terminal
is the basic unit. branches of neurons. It
stimulates impulses in the next
neuron.

19. optimum organelle
The best range that an organism A structure found in the cell that
can function in. performs a specific function.
passive transport phagocytosis
Diffusion. The movement of The process by which the a cell
molecules from an area of high flows around matter and engulf
concentration to low it in a vacuole.
concentration without the use of
energy.

20. pioneer organisms / species pituitary gland
The first organisms to live in an The "Master Gland" located in the
area. brain. It secretes numerous
hormones that affect other
endocrine glands.
plasma membrane polar bodies
The cell membrane. The semi- The small daughter cells produced
permeable outer boundary of as the egg is formed by meiotic
the cell. cell divisions.

21. polypeptide protein
A large protein composed of many An organic compound made of
amino acids joined by peptide amino acids.
bonds.
punctuated equilibrium receptor molecule
A theory of evolution which suggests A molecule that is very specific in
that species have long periods of its action because of its shape.
stability interrupted by brief periods
Its shape allows it to recognize
of significant change during which
new species are formed.
a specific stimulus and initiate a
response to it.

22. RNA (ribonucleic acid) root hairs
A nucleic acid composed of a Hairlike extensions of epidermal
phosphate, ribose and one of root cells which increase the
four nitrogenous bases; surface area for absorption.
adenine, uracil, cytosine or
guanine.
semen sex cells
A mixture of sperm and fluids that The gametes, sperm and egg
is ejaculated through the urethra
in males.

23. simple sugars small intestine
Monosaccharides such as glucose, A long coiled tube that is the site of
galactose and fructose. most of the chemical digestion
and absorption that takes place
in the digestive tract.
sperm synapse
The male monoploid (n) gamete, The gap between communicating
sex cell. neurons. Neurotransmitters
cross this gap and trigger the
next impulse in the neuron.

24. theory transpiration
A hypothesis that has been tested Loss of water vapor through the
many times to verify its stomates of the leaf.
accuracy.
ulcers uracil
Open sores in the interior walls of A nitrogenous base found in RNA.
the digestive tract.

25. urinary system variation
The system involved in the A trait found in an individual that is
production and excretion of different from the typical trait
urine. It includes the kidneys, found in members of that
ureters, bladder and urethra. species.
virus zygote
A disease-causing organism The fertilized egg. First cell after
consisting of a protein coat fertilization to be diploid (2n)
surrounding DNA or RNA.

26. active transport alveoli
A process that uses energy to The respiratory surface of the
transport materials from an area human lung. Gas exchange
of low concentration to high takes place between its thin
concentration. That is against moist membranes and the
the concentration gradient. capillaries of the bloodstream.
antibody bile
A protein produced by lymphocytes, A secretion of the liver that
which reacts with a specific emulsifies fats. It is stored in the
foreign substance, or antigen, gall bladder.
and deactivates it.

27. biodiversity cancer
Differences and variety in the A disease characterized by the
organisms and their roles in an rapid mitotic division of
ecosystem. abnormal or non-functional
cells.
carrying capacity cellular respiration
The maximum number of The enzyme controlled process in
organisms that an ecosystem which energy is released from
can support without food and converted into a form
deteriorating. that the cell can use.

28. chromotography circulatory system
A technique which is used to The system used to distribute
separate and analyze materials in an organism.
chemicals.
TRANSPORT
climax community dehydration synthesis
The mature, stable, community that The process by which two small
is the final stage of ecological molecules are joined to form a
succession. larger molecule as water is
removed.

29. dendrite differentiation
Branches of a nerve cell that carry The processes that causes the
impulses from receptors to the cells of an organism to develop
nerve cell body. into speccialized tissues and
organs. The cells get their
different jobs.
Down's Syndrome embryo
A genetic disorder caused by non- An organism in the early stages of
disjunction of chromosome 21 in development.
gamete formation, resulting in
an individual having three 21st
chromosomes.

30. endoderm enzyme
The innermost layer of cells in a A proteins that speeds up the rate
simple animal. The innermost of biochemical reactions. An
primary germ layer in an organic catalyst.
embryo.
excretory system extracellular
The system of organs used to get Outside the cell.
rid of metabolic wastes.

31. fertilization enzyme
The fusion of two monoploid A proteins that speeds up the rate
gametes (sperm and egg) to of biochemical reactions. An
produce a diploid zygote. organic catalyst.
excretory system fluid mosaic model
The system of organs used to get A model of the cell membrane
rid of metabolic wastes. which suggests that the
membrane is primarily
composed of proteins and lipids.

32. gametogenesis gel electrophoresis
Meiotic cell division in a gonad A method used to separate DNA
which produces monoploid fragments on the basis of their
gametes. size.
Golgi body hormone
A cytoplasmic organelle composed A secretion that is released directly
of flattened membranes. It into the bloodstream by an
synthesizes, packages and endocrine gland.
secretes cellular products.

33. kidney life functions
The principle excretory organ of the The activities that a living thing
urinary system. must carry out to remain alive.
Lugol's iodine lysosome
A stain that indicates the presence A small, saclike organelle that
of starch by turning from rust contains hydrolytic enzymes.
color to blue-black. The center of cellular digestion.

34. meiosis, meiotic cell division menstruation
Cell division in gonads which separates
The periodic shedding of the
the pairs of homologous
chromosomes and results in 4 uterine lining.
gametes each having the monoploid
(n) number of chromosomes.
messenger RNA negative feedback system
An RNA molecule with a specific An endocrine control mechanism
code for a polypeptide. This that responds to increased
code is determined by the levels of one hormone by
sequence of bases of the DNA decreasing the level of another.
molecule in the nucleus.

35. nucleotide nucleotide nutrition
The basic unit of nucleic acids. It The taking in and processing of
consists of a 5-carbon sugar food to make it usable.
bonded to a phosphate and a
nitrogenous base.
organ ozone
A group of tissues that carry out the Another form of oxygen having the
same function. formula O3.

36. pancreas peptide bond
An organ which produces both The bond forms between two amino
digestive enzymes and acids as a result of dehydration
hormones. It is both an synthesis.
endocrine and an exocrine
gland.
pH photosynthesis
A scale that measures the acidity or The process by which green plants
basicity of a solution. (autotrophs) convert light energy
to chemical bond energy stored
in organic nutrients.

37. protein synthesis sexual reproduction
The making of a protein from amino A form of reproduction in which two
acids by matching the anticodon gametes fuse to form a new
of the transfer RNA to the codon individual.
of the messenger RNA.
starch stomach
A carbohydrate composed of many A thick-walled, muscular,
glucose molecules; a expandable sac in the digestive
polysaccharide. system where food is
temporarily stored and protein
digestion begins.

38. succession synthesis
The replacement of one type of A chemical process in which small
community by another until the molecules are joined make large
stable climax community, which molecules.
remains until it is destroyed by
some catastrophe.
undifferentiated tissue vaccine
Cells that are unspecialized. They A serum that is injected into the
can develop into specialized bloodstream or taken orally,
providing immunity from a specific
tissues or organs.
disease. It contains weakened or
dead disease causing-organisms.
This stimulates the immune system
to produce antibodies that will result
in developing immunity to the
specific disease.

39. aerobic respiration ancestor
Respiration that uses molecular One from whom an organism is
oxygen. It produces 36 ATP as descended. For example,
one glucose molecule is parents, grandparents and
oxidized to carbon dioxide and great-grandparents.
water.
antigen blastula
A foreign substance that causes The hollow-ball stage in the
the immune system to respond development of the embryo.
by producing antibodies.

40. budding carbon dioxide
Asexual reproduction by mitotic cell CO2 An inorganic clear colorless
division which results in two gas released a 2 s an end
identical organisms of unequal product of respiration.
size.
cell theory central nervous system
The theory that states: The brain and the spinal cord.
Cells are the structural units in living things.
Cells are the functional units in living things.
New cells arise from preexisting cells.

41. cilia, cillium community
Short hair-like organelles on the All the plant and animal populations
surface of some cells. They are in a given area.
capable of movement and are
used by some protists for
locomotion.
decomposers dependent variable
Organisms of decay which convert The experimental variable that changes as a
result of the manipulation of the
organic compounds into independent variable. For example, the
inorganic compounds. change in height due to differences in
sunlight. The dependent variable is
always plotted on the y-axis.

42. diabetes diffusion
A disorder caused by insufficient The movement of molecules from
production of insulin resulting in an area of high concentration to
high blood sugar levels. low concentration without the
use of energy. .
digestive system DNA (deoxyribonucleic acid)
The specialized organs that act on The nucleic acid that stores the
nutrients as they are digested hereditary information, that is,
and absorbed by an organism. the genetic material.

43. ectoderm endocrine glands
The outermost layer of cells in a Ductless glands which produce
simple animal. The outermost hormones that are secreted
primary germ layer in an directly into the bloodstream.
embryo.
digestive system endoplasmic reticulum
The specialized organs that act on A system of membrane enclosed,
nutrients as they are digested fluid filled canals that form a
and absorbed by an organism. network within the cytoplasm of
the cell. Sometimes ribosomes
are attached to it.

44. external fertilization fertilized egg
Fertilization that takes place outside An egg that has fused with a sperm
of the mothers body. cell to form a 2n zygote.
food webs guard cells
A series of interconnecting food Specialized cells that are found on
chains in an ecosystem. the lower epidermis of leaves.
They contain chloroplasts and
control the openingof the
stomates.

45. immune system independent variable
All the bodily structures involved in The experimental variable that a
producing antibodies. scientist manipulates in order to
cause a change in the
dependent variable. For
insulin liver
A hormone produced by the Islands A large multi-purpose organ that
of Langerhans in the pancreas. produces bile, removes toxins
It lowers blood sugar levels. from the blood, deaminates
excess amino acids and
produces urea.

46. lung n
An organ found in vertebrate Letter to represent Monoploid;
animals that is used for having only one chromosome
breathing and exchanging from each of the homologous
gases between the blood and pairs.
the atmosphere.
niche nucleic acid
An organisms particular role in the An organic compound composed of
community. a phosphate, a 5-carbon sugar
and a nitrogenous base. DNA or
RNA.

47. nucleus organ system
In the cell, a large membrane A group of organs that work
enclosed organelle that contains together to carry out the major
the chromosomes. functions of organisms. Ex. the
digestive system.
oviduct receptor
A tube in which carries the egg A sense organ. A specialized
away from the ovary. structure of the nervous system
that is sensitive to a certain kind
of stimulus.

48. ribosome sickle cell anemia
The organelle that is the site of A recessive genetic disease in which
protein synthesis in the cell. the hemoglobin is abnormal and the
red blood cells have an abnormal
shape. It is found most frequently in
individuals of African descent
system tissue
A group of organs that work A group of cells that carry out the
together to carry out a specific same function.
life function.

49. transport ureter
The movement of materials from The tube which carries urine from
place to place. the kidney to the urinary
bladder.
urinary bladder villi
The organ which temporarily stores Finger-like projections in the lining
urine from the kidneys. of the small intestine that
increase the surface area for
absorption.