CP Biology Unit 1: The Nature of Life Chapter 1: Characteristics of Life

All living things share the same traits of life Big Idea #1 1. Made of one or more cells a. cell – basic unit of life b. unicellular organisms – bacteria, amoeba, etc. c. multicellular organisms – cells specialize

Unicelled organisms

2. Have DNA molecule carries instructions for all life functions Heredity – cells copy DNA and pass it to offspring “Universal” code – same for all organisms A C T G = letters in DNA code

Combining DNA from two organisms Examples – human insulin drought resistance GM (genetically modified) foods

Genetically Modified Corn Bacteria – toxin kills worm Gene for toxin put into corn Worm eats corn gene makes toxin  toxin kills worm Why not hurt humans? Concentration too small

DNA is unique to an individual DNA “fingerprint” - a pattern of stripes/bands - different for everyone - depends on order of ACTG

3. Obtain and Use Energy a. Food – for energy and raw materials b. Producers – use sunlight to make food c. Consumers – find food in environment

4. Exchange with the Environment Big Idea #2 Materials cycle Living things take in light, food, water, air - For energy, materials for growth and repair Remove wastes, die, decompose All forms of life depend on each other and on physical environment Biotic and abiotic

Chemicals CYCLE Energy does NOT cycle Environment  producers  consumers  decomposers  back to environment Energy does NOT cycle Sun  producers  other organisms. Energy is used to sustain life, some lost as heat.

a. Grow – increase in size 5. Grow and Develop a. Grow – increase in size Organisms have characteristic size and shape New cells start small, get bigger - to a point: Cells reach maximum size, then divide in two For organism to grow bigger – make more cells

b. Develop – change while maturing Multicelled begin as a single cell Cells copy and specialize (differentiate) Form many different kinds of cells Organisms change as they grow older Egg  embryo  young  adult

Bones grow longer with maturity

Stem Cells Can become different kinds of cells Depends on organism’s need, chemical signals from their environment

Big Idea #3 Simple-to-Complex 6. Are organized Big Idea #3 Simple-to-Complex Cells and organisms – different parts do specific functions

Levels of Organization in Multicelled a. Cells - made of molecules, made of different kinds of atoms b. Cells differentiate  specialized cells c. Different kinds of cells form tissues Different kinds of tissues form organs Organs work together to form organ systems Body systems work together to keep the entire organism alive.

Skin Tissue Many kinds of cells work together

Cells  tissues  organs  organ systems  organism Cells: muscle, blood, lining, gland Tissues: muscle, blood, linings, glands Organs: mouth, throat, stomach, intestine Organ system: digestive

Organization in the Environment Organism – individual living thing, makes up a: Population – group of one species living in an area. These make up a: Community – collection of living things in a particular area. These make up an: Ecosystem - collection of living and nonliving things in a particular area. All these make up the: Biosphere – layer on earth that supports life

Make new cells or new organism 7. Reproduce Make new cells or new organism New cells – for growth, repair New organism – continues the species

Reproduce By cell division Asexual – one parent - identical offspring Sexual – two parents - offspring gets genes from both parents - must be same species

Is mule a species? Species – look similar and can interbreed to form fertile offspring Mule Parents – horse and donkey Hybrid - offspring from two closely-related species - cannot reproduce  NOT a species

8. Respond to environment a. Stimulus - causes a reaction b. Response - reaction to a stimulus c. Internal or external stimuli d. Must keep homeostasis (constant internal conditions)

9. Evolve Big Idea #4 Species can slowly change over time to better fit an environment Individual organisms DO NOT evolve Earliest life 3.5 billion years ago

1.Evolution - Unifying Theory in Biology Common Origin a. all organisms descended from ancient early life forms b. changed over time into many different kinds c. modern organisms – many different kinds but show similarities in life processes, molecules, DNA

2. Unity and Diversity Life is unified – by evolution - all living things do same life functions - same chemical make-up and processes  shared ancestor Living things are diverse – by evolution - special features for different environments

3. Structure and Function “Form follows function” Features evolve to perform a function better Different environments need different kinds of adaptations

Are viruses alive? NOT part of living kingdoms LACK MOST traits of life, have only 3: Have DNA and protein Organized, recognizable size and shape Can evolve BETWEEN living and nonliving

Big Ideas in Biology All life forms share common traits – DNA, made of cells, do same life traits Living things interact with each other and with the environment (food chain, cycling) Life proceeds from simple to complex - levels of organization in organism, in environment Evolution explains unity and diversity a. Unity - All life forms share common traits - cells, DNA, life functions b. Diversity - Life evolves to suit its environment – form and function

Life Processes How do living things stay alive? All life processes work to maintain homeostasis Metabolism – all the chemical processes an organism performs

Maintain Homeostasis Consistent, stable internal conditions External changes Temperature, light, sound, motion Internal changes pH, salt, water, ions, nutrients, wastes Cells/organisms respond to changes Must restore balance quickly to survive

1. Cellular Respiration Break down food molecules for energy NOT digestion, NOT “breathing” Aerobic or anaerobic

Autotrophs (producers) 2. Nutrition Get or make food; process it for cells to use Nutrients – for energy, raw materials Autotrophs (producers) a. Make their own food b. Photosynthesis c. Base for all food chains d. Plants, algae, some bacteria

Autotrophs make food for other organisms Plants make food from small compounds in the environment. Use sunlight energy Autotrophs make food for other organisms

2. Heterotrophs (consumers) a. Take in food from environment b. Digest – break large molecules down 3. Saprobes (decomposers) a. break down wastes, dead organisms b. recycle nutrient molecules

Digestive System Breaks down food into molecules small enough to enter cells Nutrients and water absorbed by cells Liver, pancreas, and others make enzymes

3. Transport Move materials in a cell or organism Cross cell membranes Spread throughout cell Deliver needed materials, remove wastes Multicellular – need way to transport throughout organism

Animals have a circulatory system - heart, blood vessels Plants have transport tissue (veins)

Remove chemical wastes 4. Excretion Remove chemical wastes Out of cell or organism  environment Wastes are toxic Animals have excretory system Kidneys, skin, lungs Plants have pores in leaves, stems

Excretory System in Humans Kidneys – filter blood Liver – detoxify wastes Lungs – exhale CO2 Skin - sweat

Make any needed substance 5. Synthesis Make any needed substance Use molecules from food or environment Use energy from cellular respiration Example: make muscle tissue from protein

6. Reproduction Continue the species by making new organisms

7. Grow and Develop Increase in size and mature

Control rate and kinds of chemical reactions 8. Regulation Control rate and kinds of chemical reactions Respond to stimuli Keep homeostasis Unicelled, Plants – chemical messages Animals – nerves and chemicals

Nervous system Endocrine system Electric signals along nerves Fast but short-live Endocrine system Hormones sent into blood stream Cause response only in specific tissue Slower, but last longer Example: adrenaline, growth hormone

The Process of Science Evidence: can be observed or measured 1. Discovery science - tries to describe nature 2. Experimental science - tries to explain nature - hypothesis – possible answer/ solution - can be tested Question  hypothesis  data  confirmation

Independent or Dependent? Variables – affect outcome Controlled Experiment – change ONE variable Independent variable – the one you change “Manipulated” Dependent variable – depends on the independent variable “Responding”