What is Science?

The goal of science: is to investigate and understand the natural

world, to explain events and use those explanations to make predictions.

 

1. Observation – gather info in an orderly way.

2. Collect data Quantitative – numbers Qualitative – descriptive

3. Data allows us to make inferences – interpreting our data using our prior knowledge.

4. Hypothesis – An explanation for a set of observations. “educated guess” 

Designing an experiment Ask a question Form a hypothesis (prediction & reason) Set up a controlled experiment

manipulated – variable that is changed responding – variable that reacts to the

change controlled – variables (need 2) that stay the

same Record and Analyze Results Draw a conclusion Publish/Repeat experiment

Validity – Something you do in the experimental procedure to get accurate data.

Reliability – Repeating an experiment

Constraint – a problem you encounter while designing a solution to a scenario.

Limitation – an explanation of your solution to the scenario -

When evidence from numerous investigations builds up a hypothesis may become so well supported that we call it a theory.

Theory – WELL TESTED explanation that unifies or explains a broad range of observations.

  Example: Why are marsupials (kangaroo) only

found in Australia? Both the theory of plate tectonics and the theory of evolution work together to answer this question. 

Characteristics of Living Things

1. Living things are made up of cells.

Animal Cells – Cheek cells

Plant cells - Elodea

2. Living things reproduce.

Sexual – 2 different cells unite

Asexual – single parent, cell divides in half (bacteria)

3. Living things are based on a universal genetic code. D.N.A.

4. Living things grow and develop.

differentiation – where cells look different and perform different functions.

Nerve cell

Skin cell

5.Living things obtain and use materials and energy.

Metabolism – the building up or breaking down materials to carry out life processes.

6. Living things respond to their environment. Stimulus – a signal to which an organism

responds.Examples: Temperature, Light

Low blood glucose in animals = hunger

7. Living things maintain a stable internal environment.

Homeostasis – the ability to keep internal conditions constant.

8.Living things, taken as a group, change over time.

Evolution – change over time.

Different branches of Biology study living systems at different levels of organization

Metric system – based on the number 10.

100 cm = 1 meter 10 cm =____ meter 12 mm = ____ centimeters

Which one doesn’t belong?

Light – magnify by focusing visible light Electron – magnify by focusing beams of

electrons. Require a vacuum to operate so they can only look at preserved specimens.

2 Types

1. SEM – Scanning (external detail)

2. TEM – Transmission (internal detail)

A-D Scanning Electron Microscope E Transmission Electron Microscope

F Light Microscope

Can you identify which type of microscope took pictures A-F?

Laboratory Techniques Cell culture – take a single cell,

add a nutrient solution and grow more cells….

Cell fractionation – this technique is used when you want to study one part of a cell so you have to separate the cell parts.

Steps blend cells add liquid put in centrifuge tube and spin cell parts will separate by density