Living Environment

169 Pages·2015·12.34 MB·English

Living Environment

Notes

Mrs. J. Frydberg
Living Environment Notes
© 2015 J. Frydberg

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Table of Contents

Notes

Chapter 1 – The Science of Biology 5
Chapter 18 – Classification 11
Chapter 2 – The Chemistry of Life 15
Chapter 7 – Cell Structure and Function 24
Chapter 8 – Photosynthesis 35
Chapter 9 – Cellular Respiration 40
Chapter 10 – Cell Growth and Division 45
Chapter 35 – Nervous System 49
Chapter 36 – Skeletal, Muscular, and Integumentary Systems 57
Chapter 37 – Circulatory and Respiratory Systems 63
Chapter 38 – Digestive and Excretory Systems 72
Chapter 39 – Endocrine and Reproductive Systems 81
Chapter 40 – Immune System and Disease 92
Chapter 11 – Introduction to Genetics 99
Chapter 12 – DNA and RNA 105
Chapter 13 – Genetic Engineering 115
Chapter 14 – The Human Genome 120
Chapter 15 – Darwin’s Theory of Evolution 125
Chapter 16 – Evolution of Populations 130
Chapter 17 – The History of Life 135
Chapter 3 – The Biosphere 143
Chapter 4 – Ecosystems and Communities 151
Chapter 5 – Populations 160
Chapter 6 – Humans in the Biosphere 163

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Chapter 1 – The Science of Biology

1-1 What is Science?

Biology – the study of life. It is the science that seeks to understand the living world.

 The goal of science is to investigate and understand the natural world, to explain events in
the natural world, and to use those explanations to make useful predictions.

Science is an organized way of using evidence to learn about the natural world.
Observation is the process of gathering information about events or processes in a careful,
orderly way. Data is the information gathered from observations. An inference is a logical
interpretation based on prior knowledge or experience. A hypothesis is a proposed scientific
explanation for a set of observations. A hypothesis must be in the form of a statement, not in
the form of a question.

 Whenever possible, a hypothesis should be tested by an experiment in which only one
variable is changed at a time. All other variables should be kept unchanged, or controlled.

1-2 How Scientists Work

Designing an Experiment:
 Identify the problem to be solved by asking a question
 Form a hypothesis (educated guess) – must be in the form of a statement
 Set up a controlled experiment – the independent variable is the one that is
manipulated or changed; the dependent variable is what we observe changing in
response to the manipulated variable
 Record and analyze results – collect observations and data
 Draw a conclusion – use data to evaluate the hypothesis and make a conclusion

Repeating Investigations
It is necessary to repeat experiments/investigations to show the results are the same
each time and ensure the results are reliable. Experiments should have a large sample size to
increase precision.
Example: Redi’s experiment on spontaneous generation (life from nonliving). In
1668, Francesco Redi challenged the idea of spontaneous generation using jars with meat
(uncovered, covered, and with a gauze covering). It showed that maggots appeared on the
meat when uncovered but not on meat when covered.

Redi’s experiment:

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In the 1700s, John Needham challenged Redi’s work, claiming spontaneous
generation could occur under the right conditions. He boiled gravy to kill microorganisms
but days later the gravy was filled with microorganisms. Lazzaro Spallanzani read about
both expriements and showed microorganisms will not grow in boiled gravy when the flask
is sealed but will grow when the flask is open. Many scientists argued his experiment was
unfair because no air = no life.
In the 1800s, Louis Pasteur used a curved neck flask to prove Spallanzani was
correct. He boiled a broth which remained free of microorganisms for a year; once the
curved neck was broken off the flask, microorganisms began to grow in the broth.
A hypothesis can be considered a theory if it is well supported by observations and
data from many investigations.

Pasteur’s experiment:

 In science, the word theory applies to a well-tested explanation that unifies a broad range
of observations.

1-3 Studying Life

Characteristics of Living Things
Describing what makes something alive is not easy. No single characteristic is
enough and many nonliving things share traits with living things.

 Living things share the following characteristics:
 Made of units called cells (unicellular and multicellular)
 Reproduce (sexual and asexual)
 Genetic code (DNA – deoxyribonucleic acid)
 Grow and develop
 Obtain and use materials and energy (metabolism)
 Respond to the environment (stimulus)
 Maintain stable internal environment (homeostasis)
 As a group, change over time (evolution)
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Some properties of life:

Unicellular means single-celled. Multicellular means many-celled. Sexual
reproduction involves cells from two different parents uniting to produce the new organism.
Asexual reproduction involves only one parent. Metabolism is the combination of chemical
reactions through which an organism builds up or breaks down materials as it carries out its
life processes; it is all the activities an organism must perform to sustain life. A stimulus is a
signal to which an organism responds. Homeostasis is the process by which organisms
maintain a constant internal environment. Evolution is the ability of a group of organisms to
change over time.

Branches of Biology
Various branches exist: zoologists – animals, botanists – plants, paleontologists –
ancient life. Some fields focus on living systems at different levels of organization:
 Biosphere – any part of earth where life can exist
 Ecosystem – community and the nonliving environment
 Community – populations that live together in an area
 Population – group of same species in an area
 Organism – individual
 Groups of cells – tissues, organs, and organ systems
 Cells – basic units of life
 Molecules – groups of atoms; smallest unit of compounds

 Some of the levels at which life can be studied include molecules, cells, organisms,
populations of a single kind of organism, communities of different organisms in an area, and
the biosphere. At all these levels, smaller living systems are found within larger systems.
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Levels of organization:

8 Life Functions/Processes
1. Regulation – maintains homeostasis; control and coordination of all life processes
2. Nutrition – take materials from environment and change them to useful forms for
growth and repair; includes ingestion, digestion, and egestion
3. Transport – substances move into, are distributed within, and move out of cells
4. Respiration – releasing chemical energy stored in nutrients
5. Synthesis – building complex substances from smaller ones
6. Growth – increase in organism size due to increase in cell size and/or cell number
7. Excretion – removal of metabolic wastes (CO2, water, salt, and nitrogen compounds)
from chemical reactions
8. Reproduction – new individuals are made; this is the only life function that is NOT
needed for the survival of the individual (but is necessary for survival of the species)

1-4 Tools and Procedures

Common Measurement System
Scientists need a common system of measurement in order to replicate each other’s
experiments. The metric system is a decimal system of measurements whose units are absed
on certain physical standards and are scaled on multiples of 10. Length = meter, mass =
gram, volume = liter, temperature = Celsius.

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Metric conversion chart:

 Most scientists use the metric system when collecting data and performing experiments.

Microscopes
Microscopes are devices that produce magnified images of structures that are too
small to see with the unaided eye.

 Light microscopes produce magnified images by focusing visible light rays. Electron
microscopes produce magnified images by focusing beams of electrons.
Parts of a compound light microscope:

The compound light microscope allows light to pass through the specimen and uses
two lenses to form an image (magnification of about 1000 times). The electron microscope
uses beams of electrons to produce an image that is usually 1000 times better than the light
microscope.

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Size range of cells and microscopy:

Lab Techniques
A cell culture is a group of cells grown in a nutrient solution. Cell fractionation is
used to separate different cell parts. Cells are broken by a special blender, added to liquid in
a tube, and then placed in a centrifuge which spins to separate the cell parts by density.

Cell fractionation:

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