Themes of Biology (Characteristics of Life)

Ms. Day/ Honors BiologyLecture #19/3/2014

Themes of Biology MythsMyths

All livings things must:1. Eat2. Sleep3. Breathe4. Move

NOT NECESSARILY NOT NECESSARILY TRUE!!!TRUE!!!

Themes of BiologyThemes of Biology• Also known as “Characteristics of

Life”

• All living things called organismsorganisms have all these themes at least one time in their lives.

• OrganismOrganism = a single living thing• Species Species = a group of the same

living things (organisms) living in the same place at the same time

Themes of Biology Themes of Biology (Characteristics of Life)(Characteristics of Life)

1. Organization• All living things are made up of 1 or more cells.• Cell= life’s basic unit of structure and function

Organisms are either:1. Unicellular = made up of 1 cell• EXAMPLE: Bacteria• NOT very organized or structured

• Multicellular = made up of 2 or more cells• EXAMPLE: Plants, animals or people• VERY organized and structured (cells tissue organ system organism)

2. Reproduction2. ReproductionAll living things need to make more of

themselves so they do not go EXTINCT!

ReproduceReproduce = to make more of a particular group of organism

3. Inheritance All living things need to be able to pass down DNA (genes) to their offspringoffspring (“babies”).

Heredity = the passing down of genes from 1 generation to the nextGenetics = the study of heredity

DNADNA (Deoxyribonucleic Acid) = genetic material

GeneGene = a piece of DNA which codes for a protein or mRNA that gives an organism a characteristic

4. Interaction 4. Interaction with with EnvironmentEnvironmentAll living things need to be able to

respond to their environment (called “responding to stimuli”).

InterdependenceInterdependence = when living things depend or are affected by other organisms and their environment

• Example: • People take in oxygen and release carbon

dioxide. Plants take in carbon dioxide and release oxygen.

• They are interdependent on one another!

5. Energy5. EnergyAll living things need energy called ATPATP

(aadenosine ttripphosphate). – energy molecule in organisms

Organisms are either:• Producers Producers = they make their own food for

energy (Example: bacteria, plants, some algae)

• Also called autotrophs (“self feeders”)Also called autotrophs (“self feeders”)

• ConsumersConsumers = they eat other organisms for energy (Example= animals and people)

• Also called heterotrophs (“other feeders”)Also called heterotrophs (“other feeders”)

Organisms use metabolism to make ATP. Organisms use metabolism to make ATP. • Metabolism Metabolism = all the chemical processes in a

cell, including making ATP (energy)• EXAMPLE: When cells change nutrients into chemical EXAMPLE: When cells change nutrients into chemical

energy (ATP)energy (ATP)

6. Regulation6. RegulationAll living things need to regulate their

functions.

Organisms use homeostasishomeostasis to do this.

HomeostasisHomeostasis = maintaining a balance between internal and external conditions

• EXAMPLES:

– Shivering – Sweating– Pupil of an eye dilating – Panting (dogs)

7. Adaptation and Evolution7. Adaptation and EvolutionAll living things need to be able to

change over time in order to survive better.

AdaptationAdaptation = when speciesspecies change genetically over a SHORTSHORT period of time in order to better survive and reproduce in their environment

• EXAMPLE: Rabbits that are faster runners.

EvolutionEvolution = when living organisms adapt and genetically change over a LONG period of time.

• EXAMPLE: All life on Earth shares a common ancestor.