Biology 1 What is Biology Biology is the

Biology 1

What is Biology? • Biology is the study of all living things • Living things are called organisms • Organisms include bacteria, protists, fungi, plants, & animals 2

All Living Things Share Common Characteristics 1. Basic Unit is the Cell 2. They Reproduce 3. All Based On Universal Genetic Code (DNA) 4. Grow & Develop 3

Common Characteristics 5. Obtain & Use Materials & Energy 6. Respond To Their Environment 7. Maintain A Stable Internal Environment 8. AS A GROUP, Living Things Evolve, That Is They Change Over Time 4

Characteristics of Organisms 5

All Organisms are made of Cells 6

Facts About Cells • Cells are the smallest living unit of an organism • All cells contain living material called cytoplasm • All cells are surrounded by a cell membrane that controls what enters & leaves the cell 7

More Cell Facts • Cells are complex & highly organized • Cells have parts called organelles that do different jobs e. g. Chloroplasts in plants make sugars 8

More Cell Facts • The simplest cells are called Prokaryotes • These cells DO NOT have a nucleus or membrane-bound organelles • Bacteria are examples 9

More Cell Facts • More complex cells are called Eukaryotes • These cells DO have a nucleus and membranebound organelles • Plants, animals, protists, & fungi are examples 10

Organisms are Grouped by their Number of Cells • Unicellular Organisms – Living Organism Made Up Of One Cell • Multicellular Organisms – Living Organism Made Up Of Many, Specialized Cells 11

Organisms Reproduce to Pass on their Genetic Traits 12

Two Types of Reproduction • Sexual Reproduction • • • Involves 2 parents Egg fertilized by sperm to make a ZYGOTE Offspring DIFFERENT from parents 13

Two Types of Reproduction • Asexual Reproduction • • • Involves a single organism or cell Cell divides Offspring IDENTICAL to parent 14

Cells Have a Genetic Code 15

Genetic Code • DNA (deoxyribose nucleic acid) carries the genetic code for all organisms • All organisms contain DNA • DNA codes for the proteins that make up cells & do all the work 16

Organisms Grow & Develop 17

Growth & Development • Organisms grow by producing MORE CELLS & by cell ENLARGEMENT • Organisms develop as they mature into an adult organism 18

Cells Require Food & Energy 19

Food Requirements • Autotrophs can make their own food • Photoautotrophs use sunlight to make food (photosynthesis) • Chemoautotrophs use chemicals such as iron & sulfur as their energy 20

Food Requirements • Heterotrophs can NOT make their own food • They must consume other organisms • Herbivores eat plants • Carnivores eat meat • Omnivores eat plants & animals 21

Metabolism • Sum of all the chemical reactions in an organism • All require energy • Sunlight is the ultimate energy for life on Earth 22

Metabolism • Cellular Respiration – Cells releasing the chemical energy stored in foods 6 O 2 + C 6 H 12 O 6 6 CO 2 + 6 H 2 O 23

Organisms Respond to Stimuli • Organisms Respond to stimuli (Temperature, Water, Food Supplies, etc. ) In Order To Survive & Reproduce 24

Homeostasis • Keeping The Internal Environment (Homeostasis) Of The Cell or Organism Within The Ranges Required For Life • Stable internal conditions of p. H, temperature, water balance, etc. 25

Living Things Evolve • Groups Of Organisms (Not Individuals) Change Over Time In Order To Survive Within Changing Environments. • Fossil records show changes in groups of organisms 26