Studying Life Chapter 1.3

What is “Biology” Biology is the science that seeks to understand the living world “The study of life and how they interact”

Interactions With each other With other animals With people

Characteristics of Life What is life? What is needed to “be alive”?? How can you classify all living things? What must they do or have the ability to do?

Living things share the following eight characteristics: Living things are made up of units called cells Living things reproduce Living things are based on a universal genetic code Living things grow and develop Living things obtain and use materials and energy Living things respond to their environment Living things maintain a stable internal environment Taken as a group, living things change over time

1. Made up of Cells Small units that make up life A Cell is a collection of living matter enclosed by a barrier that separates the cell from its surroundings Can be unicellular (made up of only one cell) or multicellular (made up of many cells)

2. Reproduction Must be able to produce new organisms Can be done using: Sexual Reproduction where two parent cells unite to form offspring or Asexual Reproduction where the new organism has a single parent

3. Based on a Genetic Code Offspring usually resemble their parents Inherit these traits in the reproduction process Passed on through DNA using their genetic code to produce the offspring

4. Growth and Development All living things grow during at least part of their lives For many organisms, development includes periods of rapid and dramatic change

5. Need Materials and Energy Organisms need materials to stay alive The combination of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes is called metabolism

6. Response to the environment Organisms detect and respond to stimuli from their environment A Stimulus is a signal to which an organism responds Can be external (from the environment like light or temperature) or it can be internal (from inside the organism like sugar levels in the blood)

7. Maintaining Internal Balance Things are always changing around us but we need to maintain a constant set of conditions Homeostasis is maintaining a fairly constant set of internal conditions, such as temperature, water content, salinity, and pH Think about sweating and shivering… think about the “Homeostasis of the Eye Lab” that we did

8. As a group, we change over time Organisms will always grow and change over time to make the best of their surroundings and conditions Species will evolve to be better suited for their climates, food selection, and availability of other necessary resources (water, mating patterns, habitat, etc.)

Midway “checkpoint” questions Lets discuss and answer the following questions: Describe 5 characteristics of life Compare sexual and asexual reproduction What biological process includes chemical reactions that break down materials? What is homeostasis? Give two examples of homeostasis and explain how the organism maintains this “happy balance”

Branches of Biology Living things come in many different shapes, sizes, and habits Living systems also range in size from groups of molecules that make up structures inside cells to the collections of organisms that make up the biosphere. No single biologist could study this diverse

What CAN we study?? Molecules Cells Organisms Populations of a single kind of organism Communities of different organisms in an area The biosphere (the part of the earth that contains all ecosystems **REALLY, we can study the smallest thing all the way up to the largest groups

Copy the Following Table in Your Notes Levels of Organization Biosphere Ecosystem Community Population Organism Groups of Cells Cells Molecules Groups of atoms; smallest unit of most chemical compounds Increasing in Size

Copy the Following Table in Your Notes Levels of Organization Biosphere Ecosystem Community Population Organism Groups of Cells Cells Smallest functional Units of life Molecules Groups of atoms; smallest unit of most chemical compounds Increasing in Size

Copy the Following Table in Your Notes Levels of Organization Biosphere Ecosystem Community Population Organism Groups of Cells Tissues, organs, and organ systems Cells Smallest functional Units of life Molecules Groups of atoms; smallest unit of most chemical compounds Increasing in Size

Copy the Following Table in Your Notes Levels of Organization Biosphere Ecosystem Community Population Organism Individual living things Groups of Cells Tissues, organs, and organ systems Cells Smallest functional Units of life Molecules Groups of atoms; smallest unit of most chemical compounds Increasing in Size

Copy the Following Table in Your Notes Levels of Organization Biosphere Ecosystem Community Population Group of organisms of one type that live in the same area Organism Individual living things Groups of Cells Tissues, organs, and organ systems Cells Smallest functional Units of life Molecules Groups of atoms; smallest unit of most chemical compounds Increasing in Size

Copy the Following Table in Your Notes Levels of Organization Biosphere Ecosystem Community Populations that live together in a defined area Population Group of organisms of one type that live in the same area Organism Individual living things Groups of Cells Tissues, organs, and organ systems Cells Smallest functional Units of life Molecules Groups of atoms; smallest unit of most chemical compounds Increasing in Size

Copy the Following Table in Your Notes Levels of Organization Biosphere Ecosystem Community and its nonliving surroundings Community Populations that live together in a defined area Population Group of organisms of one type that live in the same area Organism Individual living things Groups of Cells Tissues, organs, and organ systems Cells Smallest functional Units of life Molecules Groups of atoms; smallest unit of most chemical compounds Increasing in Size

Copy the Following Table in Your Notes Levels of Organization Biosphere The part of earth that contains all ecosystems Ecosystem Community and its nonliving surroundings Community Populations that live together in a defined area Population Group of organisms of one type that live in the same area Organism Individual living things Groups of Cells Tissues, organs, and organ systems Cells Smallest functional Units of life Molecules Groups of atoms; smallest unit of most chemical compounds Increasing in Size

Biology in Everyday Life In this class, you will see that more than any other area of study, biology touches your life every day In fact, its hard to think of anything you do that is not affected by it Biology can help people understand that humans are capable of predicting and trying to control their future and the future of the planet

What do we NOW know?? 1. Describe the AT LEAST 5 of the 8 characteristics of life

What do we NOW know?? 2. What topics might biologists study at the “community” level of organization? 3. How about at the “groups of cells” level?

What do we NOW know?? 4. What is the difference between “asexual reproduction” and “sexual reproduction”? 5. What is homeostasis? Give two examples of how homeostasis is maintained.

What do we NOW know?? 6. What biological process includes the chemical reactions that break down materials??

Test Thursday!! Keep Studying!