Each week's lecture notes will be posted on this page. Homework will be on a seperate page.
Characteristics of Living Things
I. What is Life Science?
- the scientific study of areas of science that deal with living things
- anatomy- study of parts of the body
- physiology- study of how the whole body functions
- zoology- study of animals
- microbiology- study of viruses and very small living things
- ecology- study of the way living things interact with their environment
- Importance of Science
- Affects your life in many ways
a. medicinal; creams for acne, operations, cures for cancer
b. foods; plants, yogurts, cheeses
II. What are living things?
- living things
- Six Characteristics of living things
- Cells; the basic unit of structure and functions, called the building block of life.
- energy; the ability to do work or cause change
a. sunlight is considered a source of energy,
i. plants use it to make food
ii. animals get energy from sun by eating plants or animals that have eaten plants.
- Features; help organism adapt to their surroundings.
a. chameleons change color to help blend into environment
- Response; reaction to change in surroundings
a. jumping when you hear a car honk
- Change or development during their lifetime
- production of organisms of their own kind
a. pine trees
- Matter, everything around you is made up of matter, matter is any substance that has mass
a. substances can be broken down into simpler substances called elements
b. most living things are made up of: carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus.
- Compounds occur when two or more atoms from different elements join.
a. most compounds in living things are called organic compounds/
b. four main types of organic compounds found in all organisms
a. carbohydrates, made up of carbon, hydrogen and oxygen. Examples of these are sugars and starches.
i. Lipids, or fats made up mainly of carbon and hydrogen
ii. Proteins, made up of carbon, hydrogen, oxygen, and nitrogen. They are used to repair bodies.
iii. Nucleic acids; a combination of sugars, nitrogen, and other elements. These acids help contain important information about the organism, like how it is suppose to grow or develop.
- What are the needs of organisms?
1. Energy; needed for growth. Energy comes from foods we eat. Autotrophs make their own food. (plants) heterotrophs can not make their own food. (humans)
- Water. 2/3 of your body is made up of water. Needed to grow plants. Most chemical changes in living things need water in order to take place.
- Air; oxygen is needed by most living things to change food into energy.
a air is a mixture of gases
b. carbon dioxide is used by plants to make food also.
- Temperature: organisms need the proper temperature to live.
a. most organisms wouldn’t survive if it weren’t for homeostasis, the process of keeping conditions inside an organism constant, no matter what the conditions on the outside are.
b. Cold blooded animals must change their surroundings to change their body temperature.
c. Warm blooded animals have constant body temperature.
- Living space; all organisms need a place to live.
a. Living space must provide food, shelter, air, and water.
b. Must also be the proper temperature.
c. Organisms will compete for the resources in their living space.
- How do organisms use energy?
- Life Processes; the things an organism must do to stay alive.
- Ingestion and digestion
a. nutrients are needed from food. You ingest food by taking it into your body. Plants make their own food so they ingest nutrients from the soil.
b. Digestion is changing the food into a usable form.
3. Cellular Respiration; cell uses food in the form of sugar, which takes a sugar
molecule and breaks it apart. This process releases energy and carbon dioxide and water are produced. These are called by products.
- Excretion: the process of getting rid of waste products formed during life processes.
a. digestion form waste products
b. cellular respiration also forms waste productsc.
- Transport ; The moving of nutrients and waste products.
- How do organisms respond to change?
- Stimulus and Response: a change that causes a response
a. normally slower in plants than in animals
- Behavior: the way in which an organism responds to stimuli.
- Animal behavior;
a. Migration (seasonal movement)
b. hibernation (sleeplike state)
- Where do organisms come from?
1. All organisms come from other organisms of the same kind.
a. Spontaneous generation, things came from non living things. NO
b. Redi’s Experiment used meat and found that maggots laid eggs to produce worms
c. Pasteur’s Experiment used broth in a flask. Boiled it to kill all microorganisms, tipped flask to allow microorganism in in order to prove that spontaneous generation couldn’t happen.
- How do organisms make more of their own kind?
- Reproduction; the process of organisms producing new organisms.
- Asexual reproduction requires only one parent, each offspring is an exact copy of the parent.
a. fission; the simplest form of reproduction, parent organism splits in two. Bacteria reproduces by fission
b. budding; grown to a new organism by the parent the splits from the parent. Yeasts and some coral are reproduced by budding
- Sexual reproduction; two parents needed, new organism develops from joined cells. Off spring have some features from each parent or may not have features of either parent.