Characteristics of Living Things Chapter 1-Book A

Initial Questions What do plants have in common with dogs? What do bacteria have in common with fish What people have in common with SLIME MOLD?

Living things have cells

Cells A cell is the smallest unit that can perform all life processes Cells are covered by a membrane and have DNA and cytoplasm Most cells cannot be seen with the naked eye

Cell functions Some organisms are made up of TRILLIONS of cells Different types of cells have different functions For instance….nerve cells transport signals and muscle cells are specialized for movement! In organisms with one cell, different parts of the cell performs different functions (in a paramecium, part of the cell will eat, for example)

STIMULUS Stimulus: anything that causes a reaction or change in an organism or any part of an organism ALL organisms have the ability to sense change in their environment, and to respond to that change How do pupils respond to light? Stimuli (plural) can be light, chemicals, gravity, sounds, hunger, or ANYTHING that causes an organism to respond in some way

Example of Stimulus in Nature

Brainpop Video on the Venus Fly Trap http://www.brainpop.com/science/diversityoflife/carnivorousplants/

Homeostasis Organisms must maintain a stable internal environment….. For instance, what is the average human body temperature? Homeostasis is the maintenance of a constant internal state in a changing environment

Brainpop video on homeostasis http://www.brainpop.com/health/endocrinesystem/homeostasis/

Responding to External Changes What happens when you get hot? Why? What happens when you get cold? Why? Whether you’re sweating or shivering, your body is trying to return itself to normal temperature Animals control their temperature by moving from one environment to the other

Living things reproduce Organisms make other organisms similar to themselves Sexual reproduction-reproduction in which the sex cells from two parents unite, producing offspring that share traits from both parents

Asexual Reproduction Asexual reproduction: reproduction that does not involve the union of sex cells and in which on parent produces offspring identical to itself Many invertebrates are asexual, as do single celled organisms

Brainpop Video on Asexual Reproduction http://www.brainpop.com/science/reproductionandheredity/asexualreproduction/

Living Things have DNA DNA-stands for deoxyribonucleic acid Controls the structure and function of the cell When organisms reproduce, they pass copies of their DNA to their offspring (therefore offspring’s DNA resembles their parent’s DNA) Passing of traits from one generation to the next is call HEREDITY

Living things use energy Organisms use energy to carry out all life activities (making food, breathing, walking) METABOLISM: the sum of all chemical processes that occur in an organism

Living things grow and develop ALL living things grow Single-celled organisms: the cell gets larger and divides, making other organisms In other organisms, the number of cells grow, and the organism gets bigger Animals/humans also develop as they go through different life stages