Laboratory SafetyMiss Sabia

Lab Safety Rules

0See handout from yesterday0Check out this rap

UNIT 1: CHARACTERISTICS OF LIVING THINGSMiss Sabia

8A-Living Environment Regents

What is Biology?

0Biology is the science that seeks to understand the living world.

How can we define “life”?

Characteristics of Living Things

0Made up of units called cells0Can reproduce

0Are based upon a universal genetic code0Can grow and develop

0Obtain and use nutrients and energy0Respond to their environment

0Maintain a stable internal environment0Change over time (as a group)

Made of Cells

0Cell: collection of matter enclosed by a barrier that separates the cell from its surroundings0Unicellular: made of one cell0Multicellular: made of more than one cell

Reproduction

0Produce new organisms0Sexual reproduction: cells from 2

different parents unite to form offspring (meiosis)0Asexual reproduction: offspring has as

single parent (mitosis)

Universal Genetic Code

0Asexual reproduction—offspring and parent have same traits

0Sexual reproduction—offspring differ from parents in some ways

0Genetic code=DNA0All living organisms follow this code0Determines your inherited traits

Growth and Development

0Can lead to an increase in size, a change in form, or an increase in #

Obtain Nutrients and Energy

0Metabolism: (sum of an organism’s life processes)0 The combination of chemical reactions through which

an organism builds up or breaks down materials as it carries out its life processes

0Autotrophs: obtain energy directly from sunlight0 photosynthesis

0Heterotrophs: obtain energy by consuming other organisms 0 respiration

Respond to Environment

0Detect and respond to stimuli from their environment0Stimuli: a signal to which an organism responds

0 i.e. switching classes when the bell rings,0 pulling hand off a hot stove,0 asking for a mint when you hear a computer restart

0Stimuli may be internal or external0 Internal—regulating blood sugar0 External—seeds germinating when soil is moist

Maintain a stable internal environment

0Homeostasis: process by which organisms maintain a stable internal environment

0Usually involves feedback mechanisms0 Such as the blood sugar example0 sweating0 Think of a thermostat

Maintain a stable internal environment

0This is the Regulation in RRREGENTS0Body systems included:

0 Endocrine system—hormones0 Nervous system—uses nerve cells

Concept Map

0Work in groups to connect the words into a web that all stems from “Biology”

Quick Lab0Materials: hand lens, unknown objects (dry), same objects

soaked in water0Procedure: 01. Examine the dry unknown object in jar A. Record your

observations.02. Predict what you expect to see when the same object is

soaked in water03. Examine the object that has been soaking in water for a

period of time in jar C. Record your observations. Wash your hands.

0Conclusion: Which of these objects were alive?

15 minutes

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Viruses, Bacteria, Prions, Ribosomes, and Cells

0Read the brief passage about each of these, and characterize each as living or non-living.

(15-20 minutes)