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What Is Biology?• The study of living things.
Biologists Study?• Characteristics• Classifications• Interactions between organisms• Health & Disease
Levels of Organization(Place in Order from Smallest to Largest)
Tissues Cells
Organs Atoms
Molecules Organ Systems
Characteristics of Living Things
1. Made Up of Cells2. Reproduction3. Based on a Genetic Code 4. Growth and Development5. Need for Materials and Energy6. Response to the Environment7. Maintaining Internal Balance8. Adapt & Evolve
1. Living Things are made up of Cells.
✓ Cells are basic unit of life✓ CELL: Collection of living material
enclosed within a barrier
✓ Unicellular: one cell✓ Multicellular: many cells
2. Living Things Reproduce: ✓produce offspring which resemble parents
2 Types:
Asexual reproduction: only 1 parent
Sexual reproduction: 2 parents
Asexual
Sexual
From Dog To DNA…………1. A dog is made up of more than a million cells.
2. Each cell contains a nucleus containing chromosomes.
3. The cell’s Nucleus
4. A Chromosome
5. DNA molecule folds to form a chromosome
6. DNA is made of 2 strands.
A Cell
4. Living things Grow and Develop✓ GROWTH: increase in size & shape
✓ DEVELOPMENT: mature over time
✓ Living things have a Lifespan
Growth
DevelopmentGrowth
5. Living Things Use & Need Energy Energy comes from food, used to maintain body
• AUTOTROPH: produce own food
• HETEROTROPH: must consume food
•DECOMPOSER: breaks down dead material for food
6. Living things respond to their surroundings
✓ React to a stimulus a signal or change causing an organism to respond.
- The change could be internal or external.
✓ A response is a reaction caused by an action.
7. Living things maintain a Stable Internal Environment✓ HOMEOSTASIS or DYNAMIC EQUILIBRIUM
Examples: sweating, panting, shivering, etc.
HomeostasisHow Does Your Body Bring You Back To Normal?
& Why?
✓Perspiration
✓ Shivering
✓ Regurgitation
To stay cool & prevent overheating
To stay warm
Get rid of harmful wastes
HomeostasisIf you think about it, your body works the same way. Most
people maintain a constant body temperature around 98.6 degrees. That is your homeostasis. When facing conditions such as heavy exercise or hot weather, your body has numerous mechanisms to keep your temperature at homeostasis. Sweat is produced from glands in the dermis. As the water in the sweat changes from liquid to gas (evaporation), heat is lost allowing you to feel cooler. Your face gets red and flushed. This is due to the dilation of blood vessels which brings heat to the surface of your skin where it is lost to the environment.
8. Living things Adapt & Evolve ✓ Adapt to changes in the environment
✓ Change to better survive in environment
✓ Changes take place over a long period of time & involve the entire species.
Adaptation✓ A Cactus with horns
✓ A Camel’s Hump
✓ A Camel’s webbed feet, long eye lashes, & nostrils that close
To reduce water loss & protect from herbivores
To store fat & live off it when food & water are scarce
Prevent sinking in the sand & prevent sand from entering eyes, nose
Life Processes: Terms1. Nutrition
– taking materials & changing to a usable form (used for energy, growth, repair and maintenance)
➢ Digestion – large insoluble molecules changed into small soluble molecule by enzymes.➢ Ingestion – to consume (take in) a substance➢Nutrient- a substance taken in for energy
2 TypesAutotrophs – make their own food
Heterotrophs – get their food
2. Transport– Substances enter and leave cells (movement
of stuff within organism)– A system in larger multicellular organismExample: Circulatory System (arteries/veins)
3. Cellular Respiration for Energy– Cells burn food (glucose) for fuel (chemical
energy)– Energy is stored in molecules called ATP– All cells continuously undergo this process
called cellular respiration in the MITOCHONDRIA
2 Types
• Aerobic Respiration
organisms use O2 to break food to make carbon dioxide & water.
• Anaerobic Respiration No O2 used to break
down food.
4. Synthesis– Simple substances combined (build) to form
more complex substances
(Needed for growth and repair)
5. Growth- More cells & bigger cells- Humans start as 1 cell & grow and
develop into an organism of about 50 trillion cells.
Examples:Unicellular- increase cell sizeMulticellular- go through growth
called development
6. Excretion– Removal of wastes from the body
4 Types of excretion: urination defecation exhaling sweating
7. Regulation
– All the activities that help maintain homeostasis
– Regulation occurs by nerve impulses (nervous system) & the release of chemical hormones (endocrine system)
– Needed to respond to the internal & external environment
8. Reproduction– Produce new organisms of their own
kind
Two types:
• Asexual – 1 parent with identical offspring
•Sexual – 2 parents with offspring not identical
10. Metabolism
• All the Chemical Reactions that occur in every cell to maintain normal functioning.
• The building & breaking down of complex substances.
• The continuous release of energy.
Is A Virus Living?
Viruses have……..• No Growth• No Metabolism • No Reproduction (uses a host for
reproduction)
What Do You Think Now?