Characteristics of Life: Study of Life (Chapter 1)

Unit I: Organization of Life – Cell Structure & Function

Organization

Living things are made up of one or more cells – the basic unit of life

Ex. Cells from tissues, tissues form organs

Energy Use (Metabolism)

They obtain and use energy to grow, repair, and maintain life processes (10% from each animal)

Ex. Plants use sunlight for photosynthesis; humans eat food for energy

Homeostasis

They maintain a stable internal environment despite external changes

Ex. Humans regulate body temperature

Growth & Development

They increase in size and undergo changes during their life cycle

Ex. A caterpillar grows and develops into a butterfly

Reproduction

They produce new organisms, either sexually or asexually

Ex. Bacteria divide; animals reproduce sexually

Response to Stimuli

They react to changes in their environment

Ex. Plants bend toward light; humans pull away from heat

Adaptation and Evolution

Over generations, populations change to better survive in their environment

Ex. Polar bears evolved thick fur for cold climates

Atom

The smallest unit of matter

Ex. Carbon, oxygen

Molecule

Two or more atoms bonded together

Ex. Water, DNA

Organelle

Specialized structures within cells perform specialized function

Ex. Nucleus, chloroplast

Cell

Basic unit of life, carrying out life process

Ex. Nerve cell, Muscle cell

Tissue

Groups of similar cells performing a shared function

Ex. Muscle tissue, nervous tissue

Organ

Structures composed of multiple tissues

Ex. Lungs, Heart

Organ System

Groups of organs working together 

Ex. Digestive system 

Organism

Single living individual made up of organ systems

Ex. Human, trees

Population

Group of organisms of the same species living in the same area

Ex. Herd of deer

Community

All the populations of different species living together in one area

Ex. Deer, trees, birds

Ecosystem

Community plus its nonliving environment (soil, water, air)

Ex. Coral reef, Forest ecosystem

Biosphere

All ecosystems on Earth (Life zone)

Ex. Earth

Unity

Comes from shared ancestry

Ex. The forelimbs of humans, cats, whales, and bats have the same bone arrangement

Diversity

Comes from evolutionary changes over time

Ex. Polar bears developed thick fur and fat layers to survive in cold climates, while brown bears adapted to forests.

Three Domains of Life

Bacteria, Archaea, Eukarya

Bacteria

(Prokaryotic) - No Nucleus, True Bacteria

Archaea

(Prokaryotic) - No Nucleus, Like Eukarya in genetics and biochemistry

Eukarya

(Eukaryotic) - Nucleus, complex cells on organelles

Another name Eukaryote: Animalia, Plantae, Fungi

Heterotrophs

Energy from other organisms

Ex. Carnivores, Omnivores

Autotrophs

Convert light chemical energy (Photosynthesis = ATP Adenosine Triphosphate)

Ex. Herbivores, Omnivores

Matter

Non-living (abiotic) or from other living organisms

Food chain (Simple)

Representation of energy and matter move throughout living organisms

Food Web (Complex: Realistic)

Matter & Energy throughout the environment

Genus

Shared by closely related species

Specific epithet

Word combined with Genus for species

Ex. Eschrichtius Robustus (Gray Whale)

Viruses (About it)

Tiny (20nm)

Protein shell

DNA or RNA

Replicate ONLY inside living cells

Viruses (Cont.)

No Energy/Matter

No Reproduce outside cell

No response to stimuli in their environment