Transcript HB Unit 1 Foundations of Biology

Unit 1: Foundations of Biology
Section 1: The World of Biology
Section 2: Themes in Biology
Section 3: The Study of Biology
Section 4: Tools and Techniques
Section 1: The World of Biology
Biology= study of life.
7 characteristics of life
include:
1. Organization and
presence of cells
2. Response to stimuli
3. Homeostasis
4. Metabolism
5. Growth and
development
6. Reproduction
7. Change through time
Organization and Cells
• Organization= a degree of
order.
• Cell= smallest unit of life.
• Unicellular= organisms
made up of one cell.
• Multicellular= organisms
made up of more than one
cell.
• Tissues= groups of cells that
have similar abilities.
• Organs= structures that
carry out specialized jobs.
Response to Stimuli
• Stimulus= change in
environment.
• Response= reaction
of an organism to a
stimulus.
Homeostasis
• Homeostasis= the
maintanence of a
stable internal
environment.
Metabolism
• Metabolism= sum of
all chemical reactions
necessary for life such
as repair, movement
and growth.
Growth and Development
• Growth results from
the division and
enlargement of cells.
*cell division=
formation of two cells
from one
• Development is the
process by which
organisms become
more complex.
Reproduction
• Reproduction= production
of new organisms; transmits
hereditary information to
offspring.
• Asexual reproduction
involves a single individual.
• Sexual reproduction
involves two individuals.
* only trait of life not
essential for the survival of
the individual.
Change Through Time
• Evolution= ability of
populations of
organisms to change
over a long period of
time.
*important for survival
in the face of changing
environmental
conditions.
Section 2: Themes in Biology
The 3 Unifying themes
found throughout Biology:
1. Diversity and unity of
life:
All life is connected by
the genetic code;
diversity results from
descent through
modification.
-there are 3 major
domains of organisms:
Bacteria, Archaea and
Eukarya
Themes in Biology (cont’d)
2. Interdependence of
organisms:
All organisms interact with
each other and with their
nonliving environment.
-ecology= study of
organisms within their
ecosystems.
-ecosystem= communities
of organisms and their
physical environments.
Section 3: Themes of Biology (cont’d)
3. Evolution of Life
Populations of organisms
change over time in the
process of evolution.
-natural selection= organisms
with certain traits are better
able to survive and reproduce
-adaptation= trait that
improves an individual’s ability
to survive and reproduce.
Section 3: The Study of Biology
The scientific method is used to learn about the
natural world; it includes the following steps:
1. Making observations
2. Asking questions
3. Forming a hypothesis; making a prediction
4. Testing the hypothesis through experimentation
5. Collecting and analyzing data from experiment
6. Drawing conclusion(s) from data
7. Communicating data to peers or public
The Study of Biology (cont’d)
• Only 1 question is investigated at a time.
• Controlled experiments compare an experimental
group (independent/tested variable) to a control
group (no tested variable).
*dependent variable= variable that is measured
quantitatively (numbers)
• Experiments can only disprove an hypothesis
• Inference= conclusion drawn from facts and
previous data, not on direct observation
• Theory= set of related hypotheses; used to explain a
large amount of data.
Communicating Ideas
May include presenting via:
• Scientific journals
• Scientific symposia
Must be:
• Peer reviewed
• Based on actual experimentation
• Free of bias
In a scientific experiment, how many independent
variables should be tested at the same time?
A. none
B. one
C. two
D. three or more
Adam experiments with anole lizards that can change color,
depending on their environment. Adam places a green
anole lizard on a brown background and a brown anole
lizard on a green background. Adam knows that the brown
lizard should turn green and the green lizard should turn
brown, but neither of the lizards changed color. What may
have caused Adam’s results?
A. Their color changing may be affected by something else
besides the background color, such as fear or temperature.
B. They may have to move to the new background on their
own rather than being placed there.
C. They may need more time in which to change color.
D. The colors of the background may not have been
appropriate for these lizards.
A. Their color changing may be affected by
something else besides the background color, such
as fear or temperature.
Unit 1: Chemistry of Life
Section 1: Matter and Substance
Section 2: Water and Solutions
Section 3: Carbon Compounds
Section 4: Energy and Metabolism
• Atom: smallest unit
of matter that
maintains chemical
properties of
element
• Electron (e-): charge
• Proton: + charge
• Neutron: neutral
charge
Atoms
+ +
+ +
+
+
Elements
•
•
•
element: cannot be
separated or broken
down into simpler
substances by chemical
means
stable elements have
the same number of
protons and electrons
isotopes: atoms of the
same element with
different number of
neutrons
Bonding
Goal of Atoms: 8 electrons in
outer (valence) electron
shell
•
•
covalent bond: occur
between elements that are
close together on the
periodic table; form
molecules
ionic bond: occur between
metals and nonmetals; form
compounds
Polarity
•
•
•
Polar molecules have
their charges
distributed unequally.
Polar molecules can
dissolve polar
molecules
Nonpolar molecules
can dissolve nonpolar
molecules (why water
dissolves so many
things)
Properties of Water
1) Floats as a solid (ice)
•
keeps rivers, ponds, oceans from
freezing solid
2) Absorbs and retains heat
•
•
Keeps the temperature of large bodies of water from changing
too fast.
Helps us maintain our internal temperature (homeostasis)
3) Water molecules stick to each other =cohesion
4) Attraction force between water and other substances =adhesion
Solutions
•
•
•
•
solution: two or more
substances evenly
dispersed within each
other
acid: solution with more
hydronium (H3O+) ions
than hydroxide ions
base: solution with more
hydroxide (OH-) ions
than hydronium ions
buffers help prevent
changes in pH
Composition of Living Matter
Matter= anything that takes up space and has
mass (including living things)
4 basic elements found in all life= carbon,
hydrogen, oxygen and nitrogen
Lipids
Proteins
Nucleic Acids
Carbohydrates
Lipids
•
•
uses: long term
energy storage,
building block for cell
membrane.
ex: fats, waxes,
steroids
Proteins
• uses: structure, support,
communication, chemical
reactions
• made of amino acids
• ability of a protein to
function depends on its
shape
• Ex.s: enzymes,
hormones.
Enzymes
• enzymes: proteins that act as
catalysts (speed up chemical
reactions)
• substrate: the reactant that
combines with the enzyme
• active site:
special shape on
the enzyme that allows the
substrate to fit on the enzyme
• Lock and key/induced fit:
model describing enzyme
behavior
Nucleic Acids
• Uses: store and transmit
genetic info; store energy
• DNA: deoxyribonucleic acid;
contains genetic info; made
up of nucleotide units.
• RNA: ribonucleic acid;
important in protein synthesis
(creation)
• ATP: adenosine triphosphate;
main energy unit for cells
Carbohydrates
•
•
uses: provides cell
with nutrients for
quick burn energy;
building block for
chiton and cellulose;
ID’s specific cells.
ex: sugar, starch,
fiber
Energy
• energy: ability to move or
change matter
• Conservation of Mass:
matter is neither created
nor destroyed
• Conservation of Energy:
the total amount of energy
in the universe does not
change
Chemical Reactions
•
•
•
•
reactants: beginning participants in a
chemical reaction
products: formed in a chemical
reaction
activation energy: minimum energy
needed to start a chemical reaction
alignment: atoms must be correctly
aligned for a reaction to occur
ACTIVATION ENERGY and ALIGNMENT MUST
be present for a reaction to occur.