Chapter “1” General Biology Review Power Point Biology is the study of “LIFE” All living things are composed of “CELLS” All cells have the same basic “STRUCTURE” All cells are surrounded by thin coverings called cell membranes Some organisms are SINGLE-CELLED while others are MULTICELLULAR SINGLE-CELLED = composed of only one cell. Ex. Sand dollar; paramecium, ameoba MULTICELLED = composed of more than one cell ex. Humans, lice, dogs, trees

Energy is the ability to cause change The energy that drives metabolism comes from “FOOD” Animals must consumer or get their food from another source. They are called HETEROTROPHS/CONSUMERS Plants make their own food. They are called PRODUCERS/AUTOTROPHS Energy flows=sun to plants to plant eaters to meat eaters

Energy that is used by living organbisms originates from the “SUN” All living things maintain a balance within their cells and the environment through a process of “homeostasis” As a characteristic of all living things, homeostasis relates most directly to the biological theme of “STABILITY”

Homeostasis means “maintaining a stable internal environment” Homeostasis is the maintenance of constant internal conditions in spite of changes in the environment.

The characteristics that are considered distinct properties of all living things are as follows: 1. Being either unicellular or Multicellular 2. Using energy 3. Reproduction (produce offspring) 4. Pass on genetic information to offspring. 5. Responding to the environment 6. Ability to grow and develop 7. Homeostasis

REPRODUCTION =Process of making more of their own kind; All living things can reproduce Reproduction ensures the ongoing success of all species METABOLISM = Sum of all chemical reactions carried out in an Chemical reactions : metabolism:: Cells: organism (chemical reactions make up metabolism as cells make up an organism) SPECIES = Group of genetically similar organisms that can produce fertile offspring.

HEREDITY is the passing on of traits from parents to offspring Molecules of DNA inside cells encode information to direct their growth and development All livings things have DNA in their cells DNA codes for the production of proteins An animal’s traits are determined by its GENES

Gene therapy =The process of replacing a defective gene with a healthy gene Genetic engineers are transplanting plant DNA into other plants to create crops that are resistant to herbicides. This should allow genetically engineered crops to be better resistant to insecticides. Thereby cutting down on the need for insecticides Genetic engineers are trying to create plants that are more nutritionally balanced. Gene therapy is being used to manage CYSTIC FIBROSIS

Cystic Fibrosis = produces sticky mucus in the passages of the lungs. CANCER = uncontrolled cell growth HIV = virus that destroys the immune system, causing AIDS ECOLOGY = Study of the interactions of living organisms with one another and with the nonliving part of their environment

NOT a series of rigidly defined steps SCIENTIFIC METHOD NOT a series of rigidly defined steps GENERAL ORDER Observations Define the Problem (Questions) Hypothesis Predictions Controlled Testing Collect and Analyze data Conclusion

OBSERVATION Noticing something different. Ex. A scientist noticed that the number of salamanders in a pond were declining. This is an observation.

HYPOTHESIS Testable possible explanation; educated guess or a suggestion Never be proven true; you may either reject or accept the hypothesis Reject = not supported by the data

EXPERIMENTATION Two major groups Control Group = NO CHANGE/No experimental treatment Experimental Group= Single variable. It is the group that receives some type of treatment

EXPERIMENT Cont… Experimenting is used to test a hypothesis It is a planned procedure Two variables = Dependent & Independent The variable that is being measured = dependent INDEPENDENT Variable =The variable that you manipulate/change

The control group and the experimental group are not identical. A scientific theory = is not absolutely certain, it is changeable and may be revised as new evidence is presented

Possible Short Answer Questions Toads that live in hot , dry regions bury themselves in the soil during the day. How might this be important to the toads? Explain why it is difficult for a scientist to develop a vaccine that is effective against HIV?

Toads must maintain homeostasis a constant internal environment in order to function properly. Burying themselves in the soil is a way to keep their body temperature from rising too high and to keep their bodies from drying out.

It is difficult to develop a vaccine because the virus changes (mutates) very quickly. Thus scientists do not have a stable target to make the vaccine against