Chapter 1.3 NOTES: Studying Life

Biology – study of life bio = life -ology = study of

CHARACTERISTICS of LIVING THINGS: 1. living things are made of cells Cell- collection of living matter enclosed by a barrier that separates the cell from its Unicellular = one cell Multicellular = many cells

CHARACTERISTICS of LIVING THINGS: 2. living things reproduce Sexual reproduction- process by which two cells from different parents unite to produce the first cell of a new organism Asexual reproduction- process by which a single parent reproduces itself

Binary fission in bacteria Reproduction Asexual Reproduction Binary fission in bacteria Budding in yeasts Sexual Reproduction

CHARACTERISTICS of LIVING THINGS: 3. living things use DNA for reproduction

CHARACTERISTICS of LIVING THINGS: 4. living things grow and develop Growth = getting larger Development = changing shape and structure Differentiation- cells look different and perform different functions

CHARACTERISTICS of LIVING THINGS: 5. living things use energy Metabolism- set of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes

CHARACTERISTICS of LIVING THINGS: 6. living things respond to their environment Stimulus and response are involved it this. stimulus response

CHARACTERISTICS of LIVING THINGS: 7. living things maintain a stable internal environment (homeostasis) Homeostasis is a mechanism that keeps the inner environment stable no matter the conditions outside. For example, when it’s very hot outside, we humans will drink more water, take off some clothes, and look for a cooler place. We do all this to keep the temperature stable inside our bodies.

CHARACTERISTICS of LIVING THINGS: Homeostasis can be applied to: -body temperature (hot or cold) -sugar level in blood (full or hungry) -water level in body (too much or not enough) -other body systems…

CHARACTERISTICS of LIVING THINGS: 8. as a group, living things change over time Evolve- to change in the body

1-3 Section Assessment: 1. Describe 5 characteristics of living things.

2. Compare sexual and asexual reproduction.

3. What biological process includes chemical reactions that break down materials?

4. What happens to an organism if its homeostasis is disrupted and not restored?

5. Critical Thinking: Try to think of a nonliving thing that satisfies each characteristic of living thing. Does any nonliving thing have all the characteristics of life?