Download Biology – The Living Environment

Biology – The Living Environment
December 18, 2008
Mid-Term Review
A. Scientific Method – (Refer to Chapter 1, Biology the Study of Life) Pay attention to p. 17, the scientific
method.
1. Make an observation – Something makes you ask “why?”
2. Hypothesis – Form a tentative explanation for the phenomenon that you observe. The explanation
that you propose has to be testable by a controlled experiment.
3. Experiment – collect data from your experiment.
4. Analyze your data and draw conclusions based on your results. Decide whether the hypothesis was
supported or rejected. If necessary, revise your hypothesis and redesign your experiment.
5. Repeat the process. If successful, over time your hypothesis may become a theory if it is repeatable
over and over in a laboratory or real world setting. If sustained over long periods of time, theories can
become scientific law. Theories are our best guesses to explain the world around us.
B. Data – The data that you collect will be either qualitative or quantitative in nature.
Qualitative data is descriptive in nature, tending towards observable phenomena such as color, the way
an organism moves, or another observation that is not easy to quantify.
Quantitative data is data that is expressible in a numeric format, such as the femur bone from the John
Doe corpse found in the dumpster is 22 inches (56 cm) long.
(Sections A & B address information you should have learned in Chapter 1)
C. C is for Chemistry – Chapter 6
Matter is anything that has mass and takes up space.
Mass is a measurement of the amount of matter present in a sample. Mass differs from weight because
weight is the measured effect of gravity on mass. On earth a 100 kg mass will weigh 100 kg. On the
moon a 100 kg mass will weigh 16.6 kg.
Atoms are the fundamental building blocks of matter. That is to say that matter is composed of atoms.
In chemistry, atoms can be represented by symbols. For example an oxygen atom is represented by the
symbol O, carbon by the symbol C, nitrogen by the symbol N, and iron by the symbol Fe.
Atoms are composed of a nucleus, which contains positively charged protons and neutral neutrons.
Orbiting the nucleus are the negatively charge electrons. These three represent the best understood and
chemically important sub-atomic particles. Other sub-atomic particles exist, but their role in chemical
reactions is not well understood. The three sub-atomic particles are represented by the following
symbols:
Proton – p+
Neutron – n0
Electron – eAtoms differ from one and other by the number of protons found in the nucleus of the atom. The
different number of protons creates different elements, each with their own unique chemical and
physical properties. In all there are 115 known and synthesized elements. 91 elements are naturally
occurring.
Elements are arranged in the periodic table by increasing atomic number. The atomic number tells you
the number of protons in an element. Because the charge on an atom must be neutral, the atomic
number also tells you the number of electrons in an atom. Nearly the entire mass of an atom exists in
the nucleus due to the fact that p+ and n0 have approximately the same mass while an electron as 1/1840
the mass of a proton or neutron.
atomic mass of an atom = number of protons + number of neutrons in an atom
Number of neutrons = Atomic mass (rounded off) – atomic number
While all atoms of the same element have the same number of protons, atoms may contain differing
numbers of neutrons. Atoms of the same element that differ in the number of neutrons are known as
isotopes. The atomic mass represents a weighted average of the isotopes.
If you look at the periodic table of elements, you may see something that looks like the following:
Copper
29
Cu
63.546(3)
Copper is the element’s name. 29 is the atomic number which gives you the number of protons and
electrons in the element. Cu is the symbol associated with the element, and 63.546 is the atomic mass of
the element, given in amu (atomic mass units).
Compounds are substances that are made up of two or more different elements.
Organic compounds (pages 157-163) are compounds that contain both hydrogen (H) and carbon (C).
Organic compounds will also contain other elements such as oxygen (O) and nitrogen (N).
Type of Compound
Carbohydrate
Building Blocks
simple sugars
Used primarily for….
energy & energy storage
Lipids
glycerol & fatty acids
energy storage and insulation
Protein
amino acids
structural components of cells,
energy, communication
Remember that enzymes are organic catalysts that control the rate (speed up or slow down) chemical
reactions in a cell. Pay attention to the last paragraph on p. 161 that discusses what affects the activity
rate of enzymes.
D. Energy in a cell – Photosynthesis and Respiration
Understand and know the word and skeleton equations for photosynthesis (p. 225) and respiration (from
class and review notes). Pay particular attention to table 9.1 on p 237.
E. Cell Structure and Function (Chapter 7)
Know cellular organelles (both structure and function), particularly as detailed in section 7.3. Know
what Robert Hooke and Anton Van Leuwenhoek did in the context of their contributions to the cell
theory.
F. Ecology – Chapter 2.
Be able to explain the difference between a food web and a food chain.
Be able to draw a trophic pyramid and demonstrate an understanding of what types of organisms are
present at each level.
Understand how and why nutrients cycle through the environment (p. 48), you can expect to have to
draw a diagram that shows how materials cycle through the environment (53-57)
Understand what a symbiotic relationship is and the three different types that are recognized (44-45)
Be able to clearly explain the difference between abiotic and biotic factors (p.37)
G. Communities and Biomes – Chapter 3
Understand the concepts of primary and secondary succession. p. 67-68
H. Population Biology – Chapter 4
Understand the concept of a carrying capacity.
Pay attention to the diagram on p. 94
General Knowledge:
There will be a regent’s type graphing exercise on the midterm exam.