“Biology: The Science of Life”

Objectives To give a general understanding of the life science terminology. To recognize characteristics of organisms. To learn why we study biology.

What is Biology? Biology is the study of life!

Why do we study biology? To learn about the different types of living things around us To learn how each species fits into the pattern of life To appreciate the diversity of life

What kinds of questions can biology answer? What? (What are some features of this living thing?) Why? (Why does this living thing possess such features?) How? (How do these structures work?)

How are we connected to other living things? Living things don’t exist in isolation; they depend upon other living things Living things interact in a variety of ways and reasons (food, protection, etc.)

List 3 different types of work that biologist do. They work in a variety of environments Laboratories (bacteria, DNA, disease) In the field (artic, deep-sea studies, etc.) Radio tracking (tigers)

What is Life? Sometimes not so easy to recognize; biologists have formulated a list of characteristics by which we recognize living things. Anything that possesses all characteristics of life is an organism.

4 Characteristics of Living Things 1. Living things are organized – show an orderly structure; have specialized parts that perform particular functions -is when all structures & functions of an organism come together to form an orderly living system (humans – cell, body systems, etc.)

2.Living things reproduce- reproduction is not essential for the survival of an individual organism; however, it is essential for the continuation of an organism’s species (species – a group of similar-looking organisms that can interbreed & produce)

3. Living things change during their lives: Growth: increase in the amt. of living material & the formation of new structures (conception, 2, 4, 8-cells, etc.) Development: all of the changes that take place during the life of an organism (maturity level, puberty)

4. Living things adjust to their surroundings: (example: our bodies adjust to heat or cold; going down to the beach, moving up north; however, it is a slow process)

4. continued Any condition in the environment that requires an organism to adjust is known as a stimulus- ex. weather. A reaction to a stimulus is called a response- you adjust or die stimulus – it’s raining, response – get an umbrella

4. continued Any structure, behavior, or internal process that enables an organism to respond to stimuli & better survive in an environment is known as an adaptation. For example: many nocturnal animals possess large eyes for efficient vision at night; bats have radar, camels (feet, eyelashes, hump)

4. continued An organism must respond to stimuli from its internal environment also. Factors such as infection & external temp. can cause changes in body temp., quantities of water, nutrients, etc. Such changes can disrupt proper functioning.

4. continued Adjustments to internal stimuli help organisms maintain a steady internal environment An example is human sweating: Stimulus: It’s hot outside Response: You sweat and your face gets flushed which cools the body & helps your body maintain proper internal temperature

4. continued The regulation of an organism’s internal environment to maintain conditions suitable for life is called homeostasis (to maintain balance)

5 Parts of an Experiment

Parts of an experiment Independent variable – What you control in an experiment. The setup of an experiment. What is the difference in the groups? Dependent variable – The results. Your results are dependent on the set up of the independent variable. What has to be measured? Constants - anything in an experiment that remains the same throughout. What stays the same throughout the experiment?

Groups in an experiment Control Group – the group with normal conditions. The group nothing is being done too. Only 1. Not always present. Experimental Group – The group with different conditions. The group that is being tested. Can be more than 1

The Strange Case of BeriBeri In 1887 a strange nerve disease attacked the people in the Dutch East Indies. The disease was beriberi. Symptoms of the disease included weakness and loss of appetite, victims often died of heart failure. Scientists thought the disease might be caused by bacteria. They injected chickens with bacteria from the blood of patients with beriberi. The injected chickens became sick. However, so did a group of chickens that were not injected with bacteria. One of the scientists, Dr. Eijkman, noticed something. Before the experiment, all the chickens had eaten whole-grain rice, but during the experiment, the chickens were fed polished rice. Dr. Eijkman researched this interesting case. He found that polished rice lacked thiamine, a vitamin necessary for good health. 1.State the Problem. 2.What was the hypothesis? 3.How was the hypothesis tested? 4.Should the hypothesis be supported or rejected based on the experiment? 5.What should be the new hypothesis?

How Penicillin Was Discovered In 1928, Sir Alexander Fleming was studying Staphylococcus bacteria growing in culture dishes. He noticed that a mold called Penicillium was also growing in some of the dishes. A clear area existed around the mold because all the bacteria that had grown in this area had died. In the culture dishes without the mold, no clear areas were present. Fleming hypothesized that the mold must be producing a chemical that killed the bacteria. He decided to isolate this substance and test it to see if it would kill bacteria. Fleming transferred the mold to a nutrient broth solution. This solution contained all the materials the mold needed to grow. After the mold grew, he removed it from the nutrient broth. Fleming then added the nutrient broth in which the mold had grown to a culture of bacteria. He observed that the bacteria died. 1.Identify the problem. 2.What was Fleming's hypothesis? 3.How was the hypothesis tested? 4.Should the hypothesis be supported or rejected based on the experiment? 5.This experiment led to the development of what major medical advancement?

Scientific Method The scientific method is an organized, logical approach used to solve a problem or answer a question. The scientific method is a list of steps that are not set in stone but rather used as a guide for solving problems or answering questions.

Steps of the Scientific Method 1.State the Problem or Question –Before the problem or question can be stated you must do something first… Make an observation – –Observations use all or some of the senses (sight, taste, feel, hearing, or smell) to gather information. –Observations lead to questions and help identify problems. –In your research you will focus on only one question that you came up with in your observations.

Steps of the Scientific Method 2.Gather Information –Research background information to determine what is already known 3.Generate a Hypothesis –A hypothesis is a possible answer to a question or problem. –A hypothesis must be in the form of a testable statement. Example: –Correct – The amount of sunlight a plant is exposed to will affect how tall the plant will grow. –Incorrect – Maybe the height of a plant has something to do with the amount of sunlight.

Steps of the Scientific Method 4.Test the Hypothesis –A hypothesis must be tested to see if it is valid –Data collected during the experiment will either support or reject the hypothesis. –A hypothesis is tested using a controlled experiment.

Steps of the Scientific Method –A controlled experiment has the following: Constants – Variables that are kept the same during the experiment in both the experimental group and the control group. –Example: Type of plant, soil used, size of pot… Independent Variable – The variable that is purposely changed in the experiment. –Example: The amount of sunlight a plant receives. Dependent Variable – The variable that changes due to the value of the independent variable. –Example: The size of the plant. Experiment must be repeated more than once to make sure the results are valid.

Steps of the Scientific Method 5.Collect & Analyze Data –During the experiment data is collected. –After the experiment, data is organized and analyzed. Create graphs Identify patterns & trends

Steps of the Scientific Method 6.State a Conclusion –Did the data collected support the hypothesis? 7.Share results/findings –May generate a new question

THE END