Introduction to biology

INTRODUCTION TO BIOLOGY

BIOLOGY Bios-: greek for life -logy: study of A biologist uses the scientific method to study

living things Biology is the study of life

Zoology Botany Microbiology Ecology Marine Biology Genetics Cell biology Anatomy and physiology Paleontology

SO….WHAT MAKES SOMETHING “LIVING”? Made up of cells Reproduce Genetic code Growth and development Obtain and use materials (resources)

and energy Respond to their environment Maintain a stable internal environment As a group, they change over time

MADE UP OF CELLS Cell

Collection of living matter enclosed by a barrier Smallest structural unit of all living things Prokaryotic cells

Cell without a nucleus, DNA is in cytoplasm Eukaryotic Cells

Cell with a nucleus that contains the genetic material (DNA) Unicellular

“uni-” means one Organism that is made of one cell Example: bacteria Prokaryotic cells

Multi-cellular “multi-” means many Contain hundreds, thousands, even trillions of cells Many cells work together to make the living organism function Cells vary in size, shape and function Example: plants and animals

ABILITY TO REPRODUCE Asexual reproduction

Organism has single parent Genetically identical to parent Splits in half

Sexual reproduction Cells from two different parents unite to

form new organism Increases genetic variety and survival of

species

BASED ON A GENETIC CODE DNA nucleic acid that carries all the

information about the organism All living organisms have DNA, the “blue

prints” of life

GROWTH AND DEVELOPMENT Growth means increase in

size, such as certain bacteria

Development refers to cells dividing to

Includes periods of rapid growth and dramatic change

Sometimes different stages (think caterpillar)

During development, cells multiply and are assigned specific functions and roles within the multi-cellular organism…DIFFERENTIATION

OBTAIN AND USE MATERIALS AND ENERGY

Obtain energy by taking in resources

Plants-sunlight Lizard-insects

Metabolism Combination of chemical

reactions through which an organism builds up or breaks down materials to carry out life processes

RESPOND TO THEIR ENVIRONMENT Stimulus

A signal to which an organism responds External Stimuli

From environment outside organism Example- water in soil stimulates

germination Internal Stimuli

Comes from inside an organisms body Low sugar levels in blood will stimulate

you to feel hungry

MAINTAIN A STABLE INTERNAL ENVIRONMENT Homeostasis When organisms maintain a stable

internal environment that is different from the external environment

Examples: shivering and sweating

AS A GROUP, THEY CHANGE OVER TIME Evolution

Process of change When a group of organisms change over time Could occur over hundreds or millions of years

Adaptation An inherited trait that’s helps an organisms ability

to survive and reproduce in a particular environment

Over a short period of time Natural selection

The most beneficial traits for a specific group of organisms is passed on

Organisms that have that specific trait will live longer and produce more offspring than those who do not have it

The mechanism by which evolution occurs

LEVELS OF ORGANIZATION Molecular Cellular Groups of Cells Organism Population Community Ecosystem Biosphere

LEVELS OF ORGANIZATION

Molecular DNA/RNA and other molecules

Cellular Different cells

Groups of Cells (cellstissuesorgansorgan systemsorganism)

Organism A single species

Population A group of the same species

Community Many different groups of species and how they interact with

each other in a specific area Ecosystem

All the living and nonliving interactions in an area

Biosphere How all the different parts (biomes) of Earth come together Bio- means life Sphere- earth Life is found on land, in air, and in water “living Earth”

Life’s Diversity of Species Plants and animals…is there only one

type? Species

A distinct life form Biologists have identified more than one

million species There are various estimates to the actual amount

New species are discovered daily 5000 sp. of bacteria, 8600 sp. of birds,

30,000 sp. of fishes, 100,000 sp. of fungi, 280,000 sp. of plants and 1 million different species of….

INSECTS

Domains Broadest category of classification Three main domains

Domain Archea: unicellular prokary. That live in extreme environments

(very hot or very cold, extremely acidic or basic)) Domain Bacteria: All other unicellular prokary. Domain Eukarya: Organism made up of eukary. Cells

Includes 4 kingdoms: Protists, Fungi, Plants, Animals

Classification How do we organize all these species? We categorize all the different species in to

broader categories From broadest to most specific: Domain, Kingdom, Phylum, Class, Order, Family,

Genus, Species (Linnaean System of Classification)

Binomial nomenclature BREAK UP THE WORD…

BI-TWO, NOMIAL-NAME, NOMENCLATURE-NAMING SYSTEM

This is how we identify a species The African lion is called Panthera leo

What’s the genus? Panthera

What is the species? Panthera leo (you say both genus and species)