The Science of Biology biology the study of

The Science of Biology • biology, the study of life. • Means learning about the different types of living things around you; including humans. • allows to understand the natural environment form it’s core.

• biology will teach you how humans function and how we fit in with the rest of the world. • will also help you gain knowledge to help sustain the planet.

Biologists study the interactions of life • living things do not exist in isolation; they are all functioning parts in the delicate balance of nature. • Living things interact with environment, other living and nonliving things.

Characteristics of Life • can use to recognize things as living. • Only alive if has ALL characteristics. • Living thing = organism.

Characteristics of Living Things All living things: • have an orderly structure • produce offspring • grow and develop • adjust to changes in the environment

Reproduction • reproduction, the production of offspring. • essential for the continuation of a species: . • A species is a group of organisms that can interbreed and produce fertile offspring.

Living things change during their lives • Growth: increase in the amount of living material, formation of new structures. • different parts grow at different rates. • Development: All of the changes that take place during the life of an organism.

Living things adjust to their surroundings • Environment: includes the air, water, weather, temperature, & other organisms in area. • Stimulus: Anything in an organism’s external or internal environment that causes the organism to react. • Response: A reaction to a stimulus.

Living things adjust to their surroundings • Homeostasis: Regulation of an organism’s internal environment to maintain conditions suitable for its survival • Energy: Used by all organisms. • Living things reproduce, grow, develop, respond to stimuli, and maintain homeostasis by using energy.

Living things adapt and evolve • Adaptation: Any structure, behavior, or internal process that enables an organism to better survive. • are inherited from previous generations. • Evolution: The gradual change in a species through adaptations over time.

Question 1 How does society benefit from the study of biology?

Benefits include advances in medical treatments and disease prevention, learning more about how the human body functions, increasing knowledge of human relationships and better understanding of how to sustain the web of life on Earth.

Question 2 What is the origin of the term "biology"?

"Biology" comes from two Greek words, "bios" meaning life, and "logos" meaning study. Biology is the study of life.

Question 3 What are some characteristics of living things?

All living things have an orderly structure, produce offspring, grow and develop, and adjust to changes in the environment. Sometimes nonliving things have one or more of these characteristics, but unless something has all of them it is not considered to be a living thing. These plants are called Lithops from the Greek lithos, meaning “stone. ” Although they don’t appear to be so, Lithops are just as alive as elephants. Both species possess all of the characteristics of life.

Question 4 A group of organisms that can interbreed and produce fertile offspring is a(n) _____. A. organization B. species C. environment D. niche

The answer is B, species.

Question 5 What is the importance of homeostasis?

Homeostasis is the regulation of an organism's internal environment to maintain conditions suitable for survival. An example is the adjustment an organism makes in the amount of water in its cells; without the ability to make such adjustments, organisms die.

Question 6 Which of the following is an example of an adaptation? A. the gradual change in a species over time B. changing only one condition at a time during an experiment C. possessing large eyes for efficient night vision D. all the changes that take place during the lifetime of an organism

The answer is C. A structure, behavior or internal process that enables an organism to respond to environmental factors and live to reproduce is an adaptation. Evolution is the gradual change of a species over time and occurs through adaptations.

The methods biologists use • The common steps that biologists and other scientists use to gather information and answer questions are collectively known as scientific methods. • Starts with identifying a problem to solve by observing something.

The methods biologists use • A hypothesis is an explanation for a question or a problem that can be formally tested. • not a random guess. • test a hypothesis by conducting experiment. • The results help one draw a conclusion about original hypothesis.

Experimenting • experiment is an investigation that tests a hypothesis by collecting information under • controlled Think pair share: What things in the picture conditions. might show controlled conditions?

a controlled experiment • Some experiments involve two groups: ● Experimental Group ● Control Group. • control: group in which all conditions are kept the same and there is no Independent Variable. • experimental group: test group, where all conditions are the same except for the condition being tested.

Designing an experiment • In a controlled experiment, only one condition is changed at a time. • The condition that is changed is the independent variable • Termed b/c it’s only variable that affects the outcome.

• the scientist observes or measures a secondition that results from the change (the I. V. ) • This condition is the dependent variable because any changes in it depend on changes in the independent variable.

• not all investigations are controlled. • An investigation which has no control, is the type of biological investigation most often used in field work. Mice Year Snakes Mice born died 1960 Think Pair Share: Could 1970 you still draw a conclusion 1980 or form a hypothesis from 1990 data like this gathered from 2000 2001 the field? . 2 1000 200 10 800 30 400 500 15 600 550 14 620 600 15 640 580

Using tools • variety of tools used to obtain information. • Common tools include beakers, test tubes, hot plates, petri dishes, thermometers, balances, metric rulers, and graduated cylinders.

Using tools • More complex tools include microscopes, centrifuges, radiation detectors, spectrophotomet ers, DNA analyzers, and

Maintaining safety • Safety must be considered during investigations. Sharp Object Safety This symbol appears when a danger of cuts or punctures caused by the use of sharp objects exists. Clothing Protection Safety This symbol appears when substances used could stain or burn clothing. Eye Safety This symbol appears when a danger to the eyes exists. Safety goggles should be worn when this symbol appears. Chemical Safety This symbol appears when chemicals used can cause burns or are poisonous if absorbed through the skin.

Gathering Data • data: Information obtained from investigations. • Often in numerical form.

Drawing Conclusions Review data to come to a conclusion: • Was the hypothesis supported by the data? • Was it not supported? • Are more data needed? • Are there more questions to investigate?

Reporting results • Results and conclusions are reported in scientific journals, where they are available for examination by other scientists. to estimate the population of geese in Northern Wisconsin, ecologists marked 10 geese and then released them back into the population. Over a 6 year period, geese were trapped and their numbers recorded. Year 1980 1981 1982 1983 1984 1985 Geese Trapped 10 15 12 8 5 10 Number with Mark 1 1 1 0 2 1

Verify results • After data is published, other scientists can try to verify or disprove the results by repeating the procedure. • When a hypothesis is supported by data from many investigations, it is considered valid and is generally accepted by the scientific community.

Theories vs law • If a hypothesis is supported by many separate investigations, usually over a long period of time, it becomes a theory. • theory: explanation of a natural phenomenon supported by a LOT of evidence from many investigations.

Theories vs law • also facts of nature, called laws or principles, that are generally known to be true. • Law of Gravity • Laws of Thermodynamics • Principle of Density

Question 1 What is the difference between a hypothesis and an observation?

A hypothesis is an explanation for a question or problem and can be formally tested. An observation is something that has been noticed, often generating questions that lead to the formation of a hypothesis.

Question 2 A scientist conducts an experiment to test the effect of light on plant growth. In each experiment, three plants of the same variety are each given 10 m. L of water. One plant is exposed to full sunlight for 8 hours, one is exposed to full sunlight for 4 hours, and one plant is kept in a dark room. Plant height is measured after two weeks. What is the independent variable in this experiment?

Question 2 What is the independent variable in this experiment? A. soil volume B. amount of sunlight C. plant height D. amount of water

The answer is B. The independent variable is the condition that is changed. In this case, the amount of sunlight is changed for each plant. Plant heights are measured results of the experiment, so plant height is the dependent variable.

Question 3 Which of the following is the group in an experiment in which all conditions are kept the same? A. standard B. independent variable C. experimental D. control

The answer is D. Conditions are kept the same in the control group. The experimental group is the test group.

Question 4 Compare the terms "theory" and "principle".

A theory is an explanation of a natural phenomenon that is supported by a large body of scientific evidence. A principle is a fact of nature, generally known to be true, such as the law of gravity.