Text: Biology: The Study of Life Biology from the Greek words bios, meaning “life,” logos, meaning “study”; Biology is the study of life.
Biologists study the Diversity of Life • Through your study of biology, you will come to appreciate the great diversity of life on Earth and the way all living organisms fit into the dynamic pattern of life on our planet.
The Science of Biology • One of the most general principles in biology is that living things do not exist in isolation; they are all functioning parts in the delicate balance of nature. • Life on Earth includes not only the common organisms you notice every day, but also distinctive life forms that have unusual behaviors.
Biologists study the interactions of life Living things interact with their environment and depend upon other living and nonliving things to aid their survival • the study of biology must include the investigation of living interactions. • The study of one living thing always involves the study of the others with which it interacts.
Biologists study problems and propose solutions • The study of biology will teach you how humans function and how we fit in with the rest of the natural world. • It will also equip you with the knowledge you need to help sustain this planet’s web of life.
Characteristics of Living Things • Biologists have formulated a list of characteristics by which we can recognize living things. • Only when something has all of them can it then be considered living.
Characteristics of Living Things • Anything that possesses all of the characteristics of life is known as an organism.
Characteristics of Living Things All living things: • have an orderly structure • produce offspring • grow and develop • adjust to changes in the environment
Living things are organized • When biologists search for signs of life, one of the first things they look for is structure. That’s because they know that all living things show an orderly structure, or organization. • Whether an organism is made up of one cell or billions of cells, all of its parts function together in an orderly, living system.
How are living things like? • Any living thing is called an organism. • Organisms vary in size—from the microscopic bacteria in mud puddles to gigantic oak trees— and are found just about everywhere
Living things make more living things • Reproduction is not essential for the survival of an individual organism, but it is essential for the continuation of the organism’s species. • One of the most obvious of all the characteristics of life is reproduction, the production of offspring.
Species • A species is a group of organisms that can interbreed and produce fertile offspring in nature • Horse • Donkey • Mule • sterile
Species? Fertile Offspring? • Rama the camashares the limelight with three others of his species: conceived through artificial insemination: llamas were inseminated with camel semen. • father lion + mother tiger = ligerfather tiger + mother lion = tigon • Liger’s, genetically, lean toward gigantism. Tigon’s lean toward dwarfism.
Living things change during their lives Development- • Growth results in an increase in the amount of living material and the formation of new structures. All organisms grow, with different parts of the organism growing at different rates. • All of the changes that take place during the life of an organism are known as its development • Think about some of the structural changes your body has already undergone since you were born. • All life begins as a single cell. • As cells multiply, each organism grows and develops and begins to take on the characteristics that identify it as a member of a particular species. • Moth metamorphosis- http://www.youtube.com/watch?v=atOSro3_W7c
Living Things Grow and Develop • The length of time an organism is expected to live is its life span. • Some organisms have a short life span, Others have a much longer life span. • Some bristlecone pine trees have been alive for more than 4,600 years!
Living things adjust to their surroundings • Organisms live in a constant interface with their surroundings, or environment, which includes the air, water, weather, temperature, any other organisms in the area, and many other factors. • Stimulus- Anything in an organism’s external or internal environment that causes the organism to react • A reaction to a stimulus is a response.
Living Things Respond to stimuli that occur inside them. • Homeostasis is a trait of all living things. • Regulation of an organism’s internal environment to maintain conditions suitable for its survival is called homeostasis. • Living things reproduce themselves, grow and develop, respond to external stimuli, and maintain homeostasis by using energy. • Homeostasis Thermoregulation Video • http://wn.com/homeostasis?upload_time=all_time&orderby=published#/images
Energy is the ability to cause change. • Living things reproduce themselves, grow and develop, respond to external stimuli, and maintain homeostasis by using energy. • Organisms get their energy from food. Plants make their own food, • Animals, fungi, and other organisms get their food from plants or from organisms that consume plants.
Living Things Use Energy • You and most other organisms can’t use the energy of sunlight directly. • Instead, you take in and use food as a source of energy. • The energy used by most organisms comes either directly or indirectly from the Sun. • Plants and some other organisms use the Sun’s energy, carbon dioxide, and water to make food. • Organisms that do not get energy directly from the Sun must take in oxygen in order to release the energy in foods.
Living things adapt and evolve • Any structure, behavior, or internal process that enables an organism to respond to environmental factors and live to produce offspring is called an adaptation. • Adaptations are inherited • The gradual change in a species through adaptations over time is evolution.
Living things adjust to their surroundings • Organisms live in a constant • interface with their surroundings, or environment. • These include air, water, weather, temperature, and any other organisms in the area. The fox responds to the presence of a rabbit by quietly moving toward it, then pouncing. Trees adjust to cold, dry winter weather by losing their leaves. Trees that drop their leaves in the fall conserve water and avoid freezing during winter
What do living things need? • To survive, all living things need a place to live and raw materials. The raw materials that they require and the exact place where they live can vary. • All living things need a place to live, water, and food source to survive.
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 Lithopsfrom the Greek lithos, meaning “stone.” Although they don’t appear to be so, Lithopsare 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
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.
Section Objectives: • Compare different scientific methods. • Differentiate among hypothesis, theory, and principle.
Scientific HypothesisScience welcomes test to determine if a hypotheis is correct Testable explanation May help establish a theory If it can’t be tested, it isn’t based on science Often leads to new knowledge Many experiments can be done to support it and it is still a hypothesis If one experiment disproves it, it must be re-evaluated based on the new information. The new information must be considered and the hypothesis, law or principle must be changed to include the new knowledge gained
What if an experiment does not support a hypothesis? • Glass is fragile • http://www.youtube.com/watch?v=6V2eCFsDkK0 • http://www.youtube.com/watch?v=Pdy2_vi0FfM&feature=related • A scientist must be prepared to change or abandon an idea. • Feather Hammer Drop on Moon.click picture • Ex. Aristotle believed heavy objects fell faster than lighter NASA
A theory EXPLAINS how things function or occur a view that helps to explain many different phenomena A hypothesis that is supported by repeated experimentation All information supports the idea. Ex. Cell Theory & Atomic Theory Mermaid Theory- water evolution? http://www.youtube.com/watch?v=GdGBcS0avAU&feature=related
Scientific Theories Must be refined based on new information as it becomes available Atomic theory 1. solid ball 2. ball with electrons stuck to outside 3. electrons in fixed levels 4. electron cloud
A law • A law is a statement which is believed to be fact BUT offers no explanation • Ex. Newton’s 3rd Law- For every action there is an equal and opposite reaction
Scientific Methods • Scientific methods are used by scientists to answer questions and solve problems. • The development of the cell theory, illustrates how the methods of science work. • In 1665, Robert Hooke first observed cells in cork. He made the drawing shown. • The knowledge obtained when scientists answer one question often generates other questions or proves useful in solving other problems
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. • Scientific methods usually begin with scientists identifying a problem to solve by observing the world around them.
Scientific Method • 1. Recognize a problem • 2. Form a Testable idea (hypothesis) • 3. Predict consequences of a hypothesis • 4. Perform experiments to test predictions • 5. Formulate the simplest general rule that organizes the 3 main ingredients: Hypothesis, prediction, and experimental outcomes
The methods biologists use • A hypothesis is an explanation for a question • or a problem that can be formally tested. • A hypothesis is not a random guess • Eventually, the scientist may test a hypothesis by conducting an experiment. • The results of the experiment will help the scientist draw a conclusion about whether or not the hypothesis is correct.
Experimenting • To a scientist, an experiment is an investigation that tests a hypothesis by the process of collecting information under controlled conditions.
What is a controlled experiment? • Some experiments involve two groups: the control group and the experimental group. • The control is the group in which all conditions are kept the same. • In a controlled experiment, only one condition is changed at a time. • The experimental group is the test group, in which all conditions are kept the same except for the single condition being tested.
Designing an experiment • The condition in an experiment that is changed is the independent variable, because it is the only variable that affects the outcome of the experiment • While changing the independent variable, the scientist observes or measures a second condition that results from the change. • This condition is the dependent variable, because any changes in it depend on changes made to the independent variable.
Designing an experiment • Controlled experiments are most often used in laboratory settings. • However, not all investigations are controlled. • An investigation which has no control, may involve biological investigation, most often used in field work.
No control • An investigation which has no control, is the type of biological investigation most often used in fieldwork. • The design of the procedure that is selected depends on what other investigators have done and what information the biologist hopes to gain. • Sometimes, a biologist will design a second investigation even while a first one is being conducted, to answer the question. In the future health care workers may be able to GP software to input and track the geographic locations of patients who've contracted deadly, communicable diseases. Then, if an epidemic pattern began to emerge, doctors could go straight to the source and administer antivirals or vaccines before the killer gets out of control.
Not all investigations are controlled. • Suppose you were on a group of islands in the Pacific that is the only nesting area for a large seabird known as a waved albatross. • Watching the nesting birds, you observe that the female leaves the nest when her mate flies back from a foraging trip. • The birds take turns sitting on the eggs or caring for the chicks, often for two weeks at a time. • You might hypothesize that the birds fly around the island, or that they fly to some distant location, in search of food. • To test these hypotheses, you might attach a satellite transmitter to some of the birds and record their travels.