Facts you need to know to pass the Living Environment
Regents Exam
1.
2.
3.
4.
5.
The ability of an organism to maintain internal stability is known as homeostasis.
Metabolism is the sum of all the chemical reactions that occur within the cells of an organism.
Organic molecules contain both carbon and hydrogen.
Cells  tissue  organs  organs systems  organisms (increasing complexity)
Organelle is a structure within a cell that carries out a life (specific) functions.
a. Vacuoles store food, water, waste, enzymes, secretions, etc.
b. Ribosome: site of protein synthesis
c. Mitochondria change glucose and oxygen into stored energy (ATP) site of aerobic
respiration, "Powerhouse of the Cell"
d. Chloroplasts contain chlorophyll, site of photosynthesis, and convert sunlight energy
into glucose molecules, a stored form of energy
e. Nucleus: membrane bound structure that contains DNA, control center for the cells life
functions, chromosomes (made up of genes) are found here
f. Cell membrane double lipid layer: selectively permeable, sites for active transport of
large molecules and diffusion of smaller molecules
6. Cell Membrane
a. Separates the contents of the cell form the outside environment
b. Controls the transport of materials into and out of the cell
c. Recognizes and responds to chemical signals, has receptors for recognition
7. Diffusion movement of molecules from areas of high concentration to areas of low
concentration without using energy (ATP)
8. Active Transport moving a molecule from low concentration to a high concentration with
energy –(ATP)
9. Hydrolysis breaking large molecules down into smaller molecules with addition of water
a. Proteins are broken down into amino acids.
b. Starches are broken down into simple sugars (glucose)
c. Disaccharides are broken down into monosaccharides (glucose)
d. Fats (lipids) are broken down in to 3 fatty acids and a glycerol
10.Chemicals produced in the endocrine glands are hormones and chemicals produced by nerve
cells are neurotransmitters. Both are responsible for communication between cells
11.Aerobic Respiration uses oxygen to break down food (into glucose) to release energy.
12.Transport involves the movement of materials inside the cell as well as the movement
between parts of a multicellular organism.
13.Excretion is the removal of all waste produced by the cells of the body.
14.Nervous and endocrine systems control the coordination of many of the body's activities.
15.Failure to maintain homeostasis can result in disease (illness) or death.
16.Photosynthesis-Storing energy: Sunlight energy is converted into chemical bond energy in
the form of glucose, it occurs in the chloroplast
17.Respiration - Releasing energy: Glucose molecules and oxygen, with enzymes acting as a
catalyst, break down the chemical bonds and release the energy held in those bonds. The
energy is stored in a usable form called ATP. Cellular respiration occurs in the
MITOCHODRIA.
18.Enzymes are special proteins that affect the rate of chemical reactions.
19.Catalysts are any substances that can affect the rate of a chemical reaction without being
changed or used up during the reaction.
20.Enzyme reaction rates are affected by:
a. Shape - is specific to each enzyme substrate complex
b. Temperature - changes the molecule's shape and slows down or stops the chemical
reaction.
c. The pH must be correct or the reaction will slow or stop.
21.Dynamic Equilibrium - a steady state – homeostasis, the function of any body system is how the
body system maintains homeostasis.
22.Positive feedback - a change prompts a greater response. Example: a woman giving birth
23.Negative feedback - When glucose levels are above normal the pancreas secretes insulin. This
hormone prompts glucose to move from the blood into body cells, resulting in a lower glucose level
in the blood. (Another hormone secreted by the pancreas works in the opposite way. When the
glucose level in the blood is too low, this hormone prompts the release of glucose stored in the liver)
25.Illness (disease) is any condition that prevents the body from working as it should. (homeostasis
NOT maintained)
26.Cancer: certain genetic mutations in a cell can result in uncontrolled cell division.
27.Immune system is the body's primary defense against disease-causing pathogens.
28.Protein (antigen) on a molecule found on the outer surfaces of cells that the immune system
recognizes as either part of the body or an outside invader.
29.Antibody is a protein that either attacks the invaders or marks them for killing.
30.Vaccines are made using weakened, killed or parts of pathogens. Produces antibodies.
31.Heredity is the passing of genetic information from one generation to the next through
reproduction.
32.The hereditary information DNA is organized in the form of genes located on chromosomes in
the nucleus of each cell.
33.Differences between asexual and sexual reproduction:
Asexual reproduction
Sexual reproduction
Mitosis
Meiosis
One parent
Two parents
Identical genetically to parent
Genetic variation from parents
Ex: budding, binary fission
Ex: conjugation, fertilization
Organisms: hydra, ameba
Organisms: spirogyra, mammals
34.Identical genetic copies are known as clones.
35.DNA is made of a sugar, a phosphate and a nitrogen base.
36.Bases are A, T, G, C A is paired with T. G is paired with C.
37. Any alteration of the DNA sequence is a mutation which changes the normal message carried by
the gene.
a. Substitution a change base(s) a section of DNA sequence (GACGAG)
b. Deletion a removal of a section of DNA
c. Addition adding a section of DNA
d. Inversion a reversal of a section of DNA
38. RNA molecules are for protein synthesis. They determine the sequence of amino acids.
39. RNA has the nitrogen base uracil(U) instead of thymine (T)
40.An organism's environment can affect the way that some genes are expressed. Ex: Himalayan
Rabbit, Arctic Fox
41.Genetic Engineering is a technology that humans use to alter the genetic instructions in
organisms.
42.Biotechnology – fruit, veggies, cheese, bread: examples of genetic engineering to improve food
43.Selective Breeding is a process that produces domestic animals and new varieties of plants with
traits that are desirable by breeding organisms with desired traits
44.Gene splicing is adding genes to the DNA code artificially. EX: moving a human insulinproducing gene into a bacterial cell-the bacterium and its entire offspring will produce human
insulin. This provides a way to produce large quantities of a hormone at low cost.
45.Species is a group of closely related organisms that share certain characteristics and can produce
fertile (can reproduce) offspring through reproduction.
46.Differences between mitosis and meiosis
Mitotic division
Meiotic division
Asexual
Sexual
One cell division
Two cell divisions
Number of functioning cells - 2
Male 4 cells, Female 1 functioning
cells
Genetic makeup diploid (same as
Genetic makeup monoploid (half that
parent) (2n)
of the parent) (n)
Function: growth and repair, binary
Function: sexual reproduction
fission, budding
47.Gametes unite to form a fertilized egg or zygote, if the gametes each have 23 chromosomes, the
zygote will have 46 chromosomes (2n)
49.Differentiation is the process that transforms developing cells into specialized cells with different
structures and functions.
50.Female reproductive: progesterone-estrogen (hormones)-ovaries-uterus-placenta-egg (ID on
diagram with function)
51.Male-testosterone (hormone)-sperm
52.Reproductive technology
a. Artificial insemination: introduction of the sperm to the uterus of the woman with a
syringe.
b. Hormone therapy: patient takes hormones to correct reproductive sterility
c. Ultrasound: sound waves are used to bounce off the fetus in utero to capture and image of
the baby.
d. In vitro fertilization: sperm and egg are mixed together in a petri dish for fertilization
outside the woman's body then introduced to uterus after fertilization
53.Evolution the process by which organisms have changed overtime. Simplesingle
celledcomplex single celledsimple multicellular complex multicellular
54.Geologic time is based on the fossil record and radioactive dating
55.Natural selection is when nature chooses who will survive based on the best adapted to the
environment. "Survival of the fittest"
56.Overproduction is an increase in the population of a specific species beyond the normal limits
57.Struggle for survival nature selects those plants and animals whose genetic makeup creates those
that are most fit/best adapted
58.Variation: genetic differences in the population of one species can be caused by mutations
59.Any trait that helps an organism survive and reproduce under a given set of environmental
conditions is said to have adaptive value/genetic value/reproductive value
60.The failure to adapt to a changing environment may result in the extinction or death of a species
61.Extinction is the disappearance of an entire species and can occur if the environment changes
63.Ecology is the study of how organisms interact with the living and nonliving things
64.Biotic factors: plants, animals (living)
65.Biotic factors: water, soil, temperature, sun, and minerals (nonliving)
66.Habitat: where a species lives
67.Population: all the organisms of a species that live in the same area.
68.Community: all the different populations in an area
69.Biomes (collectively,biosphere): all of earth's ecosystems
70.Competition is the struggle for limited resources among organisms
71.Factors in the environment that limit the size of populations are known as limiting factors. EX:
water, food, shelter
72.The number of organisms of any species that an ecosystem can support is referred to as its
carrying capacity
73.Predators kill/eat other organisms, prey is what they kill for food
74.Niche: the role that each species plays in an ecosystem.
75.Autotrophs are plants, producers (make their own food from sunlight, water and carbon dioxide,
through photosynthesis), base of food/energy pyramid
76.Heterotrophs are consumers and obtain their food from the environment.
77. Herbivore eats plants
Carnivore eats meat.
Omnivore eats both meat and plants.
Produces are at the base of the food chain, food web, energy pyramid and consumers,
(herbivores, carnivores, omnivores) are above
Decomposers are bacteria and fungi that break down dead organisms and return their
compounds to the earth/ Scavengers eat already dead animals
Parasites live off host and do harm.
78.Differences between a food chain and a food web:
Food Chain
Food Web
Simple diagram that links one
More complex, has more connections
organism to another to show their
in the diagram with more animals
relationship
and the inter-dependent relationships
79.What is the main source of energy on the earth? SUN
80.On an energy pyramid where is the most abundant energy located? BOTTOM
81.Biodiversity is a measurement of the degree to which species vary within an ecosystem.
82.As biodiversity increases, stability of an ecosystem increases.
83.Ecological succession plants develop and change an area to a stable climax community.
84.Renewable resources-sunlight, wood Nonrenewable--oil, minerals
85.Preserving our resources:
a. Reduce-decrease pollution, choose recycled packaging
b. Reuse-use again, paper bags that are recycled material, fiber fill for jackets made from
plastic bottles
c. Recycle-cans, paper, plastic
86.Pollution a harmful change in the chemical makeup of the air, water or soil.
87.Natural processes in Ecosystems:
a. Maintaining atmospheric quality-plants recycle carbon dioxide and produce oxygen
b. Soil formation-lichens break down rock into soil (succession)
c. Water cycle-evaporation, condensation, precipitation
d. Carbon cycle-plants do photosynthesis to turn carbon dioxide into glucose.
e. Nitrogen cycle-plants incorporate nitrogen-bearing minerals into their cells to make
proteins, which we can eat. Later decomposers will break down the dead to return the
nitrogen to the soil.
f. Flow of energy-energy passed through the environment but it is used not recycled, it is
lost.
88. Human activities and the loss of diversity:
a. Direct harvesting-cutting down trees for commercial use
b. Land use-farming on land that was once forest habitat
c. Habitat destruction-removal of trees means lack of habitat for animals
d. Imported species (invasive species or exotic species) gypsy moth caterpillar was released
in NY and destroyed millions of acres of natural forest.
e. Cutting trees (logging)
f. Burning the rainforest (slash and burn agriculture)
g. Building- cities and farms
h. Diverting water- dams on rivers keeps water from its natural path
89.Impact of technology and industrialization.
a. Industrialization increases pollution of air and water, uses more energy, water and fossil
and nuclear fuels
b. Water pollution from sewage wastes from homes and factories, animal wastes
c. Toxic wastes-DDT, PCB
d. Thermal pollution heat is released into the environment killing off plants or animals
e. Air pollution burning fossil fuels, smoke or other gases such as carbon dioxide, carbon
monoxide and sulfur dioxide
a. Acid rain - sulfur dioxide mixes with water in the air to produce sulfurous acid, which
falls as acid rain
b. Smog - smoke and fog
f.Global warming-green house gases such as carbon dioxide keep in the heat instead of
allowing it to radiate out into space
g. Ozone depletion caused by the increased use of certain aerosol sprays that will break down
ozone faster than the atmosphere can replace it making a hole in the ozone layer over
Antarctica and thinner layer over the earth