BIOLOGY The Study of Life Organisms = Biology studies a number of topics CELL STRUCTURE AND Cells are the basic units of life – Unicellular = one cell, multicellular> one cell Differentiation = cells become different from each other : Blood cells Skin cells No differentiation in organisms.

Stability & Homeostasis Homeostasis is a. Organisms need to have stability In,, pH, etc. Reproduction & Inheritance Producing new organisms + =

In reproduction information is passed on using information from DNA DNA is a map  with that code for Proteins  Reproduction may be sexual in which genes are, or asexual (parent & offspring have the same genes.) Evolution – organisms best adapted to their environment (Natural Selection) This occurs gradually (1000s of years)

Biggest influence on environment = ! Example: destroying rainforests Lowers, increases, destroys, animals die, some become. Organisms interact and effect each other’s survival. Matter, Energy & Organization To maintain homeostasis, organisms need ! Stability of an environment effects in it.

 Plants (photosynthesis)  Food energy Plants are (make their own food) Animals are (eat other things) Chemicals in food are broken down  Metabolism = total of chemical processes Living things are more than nonliving things.

CHARACTERISTICS OF LIFE 1.All living things are made of. Humans have about trillion cells. 2. All have (cell parts & groups of cells have particular functions.) Levels: cells, tissues, organs, 3. All living things use (in metabolism to grow, organize, & reproduce. SOME plants are heterotrophic) 4. All have – work to regulate H 2 O, temperature, etc.

5. Living things by cell enlargement & division. Division: 1 cell  2 cells Development: cell grows & differentiates 6. Living things. (not every individual) EX. Organization: skin (epithelial) cells make Epithelial tissue that make the organ (skin) that is part of your system.

Scientific Measurement Metrics It is. It is more widely used. Length =, Mass =, Volume = liters, Temp. = degrees Celcius, Time = Density = m/v (g/l or g/cm 3 ), D of water? Kilo = = k, Hecto = 100 = h, deca = = da Deci = 1/10 = d, centi = 1/100 = c, milli = 1/1000= m, = 1/ = μ

L (larger) to S (smaller) moves decimal to the right Try these : 15 m = ? dm (dm is smaller, “.” goes right) 5000 ml = ? l 22 mg = ? kg Answers: 150 dm 5 l kg

Scientific Method 1. Observing – recognizing the Ex – Zaire, Africa – unknown disease 2. Questioning – Ex. How is the disease transmitted? Do all the victims die? 3. Collecting Data ( step) – data is all the information gathered to answer a question. There are different ways to collect data. Observing – using senses – ( ) Measuring – quantitative ( of deaths)

Sampling – using small sample to represent the (they must be large & ) Ex. Hundreds of blood samples – found virus Organizing – using graphs, charts, etc. to show data. Ex. Chart of first to last infected person 4. Hypothesizing – suggest a possible explanation. This can be tested and is never ABSOLUTELY true. Ex. The virus ( ) in the blood caused the disease.

5. Predicting – stating what you the results will be. 6. Experimenting – the hypothesis by gathering data under controlled conditions. 7. Analyzing Data – determining if the information gathered is and if it supports the hypothesis & looking for possible error. 8. Concluding – explaining results – may use a model (verbal, visual, or.)

Inference is a way of concluding – based on but not direct observations (see smoke, suppose fire.) If all you have done is correct you may now have a – broad, comprehensive statement thought to be true, based on many tests. Experimental procedure is. The best experiment is a controlled experiment.

The experiment should have a (with constant conditions for comparison) and an (with the variable you are testing.) Ex. Healthly people who lived in Zaire of similar age and overall condition as the sick people The thing you control in an experiment is the variable (x axis) The thing that results from your actions is the variable (y axis)

In the Zaire disease, they experimented by taking the from infected people and injecting it into monkey kidney cells to see if it would kill the cells. Blood from healthy people was injected too. This was the group. Set up an experiment to show if hot water helps daisies grow better. List all the steps and show your control and experimental groups.

Scientists share information at meetings, in. Scientists us the SI ( ) system of measurement. (easier, universal) One of the instruments scientists use is the. Microscopes produce an enlarged image of an object. They and keep a clear picture (good resolution.) Magnification = eyepiece lens x objective lens. Ex. 10x x 40x = x

Light microscopes only have good resolution to about 2000x As magnification ↑ ↓ Electron microscopes illuminate with and can magnify higher. Ex. TEM (transmission electron microscope) gives a good internal image up to x. SEM (scanning) gives good 3D image to x. But for both, specimen must be.