Biology and You-Chapter 1. I. Themes of Biology. A. Living Organisms have certain characteristics in common. 1. Biology is the study of life. B. Seven Themes Unify the science of Biology 1. Cellular structure and function= cells.
A. Living Organisms have certain characteristics in common.
1. Biology is the study of life.
1. Cellular structure and function= cells.
a. All living things are composed of one or more cells.
b. Cells are highly organized, tiny structures with thin membranes.
a. Reproduction is the process by which organisms make more of their own kind from one generation to the next.
a. Living organisms perform many different chemical reactions in order to obtain and use energy to run the processes of life.
b. Metabolism is the sum of all the chemical reactions carries out in an organism.
a. All living organism must maintain a stable internal environment in order to function properly.
b. The maintenance of stable internal conditions in spite of changes in the external environment is called homeostasis.
a. All living things are able to pass on their characteristics to their offspring through genes that are passed from parent to offspring each generation.
c. A change in the DNA of a gene is called a mutation.
a. Change in the inherited traits of species over time is called evolution.
b. A species is a group of genetically similar organisms that can produce fertile offspring.
c. Organisms with favorable genes are more likely to survive and reproduce natural selection.
a. A biological community is a group of interacting organisms.
b. Ecology is the science that studies the interactions of living organisms with one another and with the nonliving part of their environment.
A. Living in harmony with our environment
1. In 1999, the world’s human population was passed 6 billion people!
2. Humans are seriously harming other creatures that share our planet.
1. As the population continues to grow, the demand for food is going to strain our ability to feed all the people.
2. Genetic engineers are transplanting beneficial plants genes into other plants to create crops that are more resistant to insects and microorganisms.
1. AIDS- Acquired Immune Deficiency Syndrome.
3. Cystic Fibrosis
A. Shared observations help to solve scientific puzzles
1. Observation is the act of noting or perceiving objects or events using the senses.
C. Asking questions
1. Observations of the natural world often raise questions.
1. A hypothesis is an explanation that might be true- a statement that can be tested by additional observations or experimentation.
2. A prediction is the expected outcome of a test, assuming the hypothesis is correct.
1. An experiment (a planned procedure to test a hypothesis) must be performed.
2. A control group is a group in an experiment that receives no experimental treatment.
4. The variable that is measured in an experiment is called the dependent variable.
1. Once data are collected and analyzed, a conclusion is made as to whether the data support the hypothesis.
2. Further analysis is conducted to determine any problems in the experiment.
1. Once a scientist completes an experiment he/she will write up a report and print it in a science journal.
1. A theory is a set of related hypotheses that have been tested and confirmed many times by many scientists.
3. To the public, theory may imply a lack of knowledge, a guess.