HOMEOSTASIS- a process in which an organism keeps
its internal conditions within tolerable ranges;
equilibrium
Stimulus response feedback model:
1. STIMULUS- produces the change
2. RECEPTOR- detects the change
3. CONTROL CENTER- determines the
appropriate response
4. EFFECTOR- organ, glands, tissue, that
adjusts the amount of output that produces
a desired effect
5. RESPONSE- outcome of the adjustment
NEGATIVE FEEDBACK MECHANISM- allows the internal
condition of the body to go back to its normal state by
inhibiting/ removing the stimulus
POSTITIVE FEEDBACK MECHANISM- increase in the
concentration; enhance the original stimulus
DNA – DEOXYRIBONUCLEIC ACID
Used in different things such as:
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Growth
Development
Reproduction
BACTERIA- single celled
PROKARYOTIC
prokaryotic cell is a simple, single-celled (unicellular)
organism that lacks a nucleus, or any other membranebound organelle.
 have a cell wall made of peptidoglycan,
comprised of sugars and amino acids, and
many have a polysaccharide capsule
 the cell wall acts as an extra layer of
protection, helps the cell maintain its shape,
and prevents dehydration. The capsule enables
the cell to attach to surfaces in its
environment.
 cells range in diameter from 0.1–5.0 µm
has a true nucleus (meaning its DNA is surrounded by a
membrane), and has other membrane-bound organelles
that allow for compartmentalization of functions.
Eukaryotic cells tend to be 10 to 100 times the size of
prokaryotic cells.
Archaeans(cousins of eukaryotic)
Protist- simplest eukaryotes
Fungi
Animals
Plants
HOW CELLS REPRODUCE
GEORGE AND MARGARET GREY- cultures human cells
1951
HeLa- human cell to be experimented on test tube
(Henrietta Lacks)
CELL CYCLE- series of events from the time a cell forms
until its cytoplasm divides
1. INTERPHASE
o G1, the first interval(gap) of cell growth
o S, DNA REPLICATION
o G2, cell prepares to divide
Mitosis – nuclear division mechanism that maintains the
chromosome number
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Prophase- the duplicated chromosomes moves
to the opposite side of the nucleus
Metaphase- chromosomes aligned midway
between the spindle poles
Anaphase- moves toward opposite poles
Telophase- chromosomes reach the poles and
decondense.
(picture)
NEOPLASM- accumulation of abnormally dividing cells
GROTH FACTOR- molecule that stimulates mitosis
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EPIDERMAL GROWTH FACTOR (EGF) –
stimulates cell to enter mitosis by binding to a
receptor on the cell’s plasma membrane
EUKARYOTIC:
membrane-bound nucleus and other membrane-bound
compartments or sacs, called organelles, which have
specialized functions
TUMOR – neoplasm that forms a lump
ONCOGENE- gene that has the potential to
transform a normal cell into a tumor cell
PROTO- ONCOGENE- gene that can become
oncogene
CANCER- disease that occurs when a neoplasm
physically and metabolically disrupts body tissues
METASTASIS- process in where cancer cells spread
from one part of the body to another
NATURAL SELECTION
GREGOR MENDEL- Father of genetic
Locus- location of a gene on a chromosome
Heterozygous- 2 different allele of a gene
Genotype- particular set of gene carried by an indi
Phenotype- individual’s observable traits
Hybrid- offspring of a cross between two
individuals that breed true for different forms of
trait: heterozygous individual
Homozygous- IDENTICAL ALLELE
DOMINANT
RECESSIVE- masked by a dominant allele
LAWS OF INHERITANCE:
MENDEL’S LAW OF SEGREGATION
 An individual has a pair of each allele
LAW OF INDEPENDENT ASSORTMENT
 States that allele segregate independently
LAW OF DOMINANCE
 Codominance- mix; both traits are mix up
in the offspring
 Incomplete dominance- both allele
contributes to the phenotype
PHTOSYNTHESIS
 Chlorophyll a absorbs violet and red light ,
so it appears green to us
HOW CELLS RELEASE ENERGY
Glycolysis- set of reaction in which glucose or another
sugar is broken down to two pyruvate for a net yield of
two ATP
Pyruvate- three carbon end
Atp-is the molecule that fuels life. It is where our cells
get the energy needed to perform their tasks.
 Unlike glucose, glucose-6-phosphate does not
pass through glucose transporter in the plasma
membrane, so its trapped inside the cell.
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