University:
Missouri State University
Course:
BIO 121 | General Biology I
Academic year:

2021
Views:

424

Pages:

12
Author:

Alexa Livingston

Characteristics of Life Chapter 1, Section 3 Biology = the study of life What does it mean to be alive??? • There are 8 characteristics of life . . . – No single characteristic is enough to describe a living thing . . . – They must have all eight. 8 Characteristics of Life 1. Living things are made up cells. 2. Living things reproduce. 3. Living things are based on a universal genetic code (DNA). 4. Living things grow and develop. 8 Characteristics of Life (cont.) 5. Living things obtain and use materials and energy. 6. Living things respond to their environment. 7. Living things maintain a stable internal environment. (homeostasis) 8. Taken as a group, living things change over time. 1—Made up of cells They can be either unicellular or multicellular. Picture of a Cell ***Unicellular = made up of ONE cell Picture of a unicellular organism. ***Multi-cellular = made up of MORE than one cell Picture of multicellular organisms 2—Reproduction There are 2 types of reproduction: 1. Asexual ***asexual = reproduction that requires ONE parent 2. Sexual ***sexual = reproduction that requires TWO parents 3—Based on a genetic code ***DNA = DNA is the genetic code found in every cell. DNA is inherited from parents and controls your traits. 4—Grow and Develop **All living things grow and develop during at least part of their life. ***Think about it . . . Do you look the same as when you were born???? 5—Need for materials and energy **Living things need a constant supply of materials and energy. **Metabolism = the process of using those materials. 6—Response to the environment **Organisms detect and respond to STIMULI (or signals) from their environment. **Internal stimuli = signal comes from inside the organism **External stimuli = signal comes from outside the organism 7—Maintaining internal balance Despite changing conditions around them, organism must keep their internal conditions stable/balanced. **Homeostasis = the process of keeping the internal environment stable/balance/constant 8—Change over time Over hundreds, thousands, and millions of years, organisms have the potential to change = evolution