Chapter 2 The Science of Biology

What is Science? Science is derived from a Latin verb meaning “to know.”

Inquiry What is inquiry? A- People ask questions about what they observe in nature and actively seek answers. Ex. Houseplants grow toward a light source. If we rotate the plant will its direction of growth still go toward light source? What direction would the plant grow In the dark?

Observation and Data The questions that drive scientific inquiry are based on observations. Observation- Use of senses (vision or hearing) to gather information. Data- Recorded observations.

Quantitative vs Qualitative Data Quantitative: Collecting data with numbers. Ex. Measurements. Qualitative: Writing with descriptions instead of measurements. Pictures and drawings. Ex. Jane Goodall spent decades recording her observations of chimpanzee behavior in the jungle.

Quantitative vs Qualitative? 1. The lion woke up at sunrise everyday and cleaned his paws. This lion mated with the females lions. A. Qualitative

Quantitative vs Qualitative? 2. There were 7 ant hills in the grass. The alligator grew 1 inch every week. A. Quantitative

Inference Inference- A logical conclusion based on observations and prior knowledge. Ex. What can you infer if you hear a doorbell ring? A. When a doorbell rings you infer that someone is at the door.

Observation: Four place setting No drinking cups Empty plates Infer: Four people Food is somewhere hidden Drinks will be from cans

What can you observe from this graph? Girls start out taller than boys Boys eventually are taller than girls

2.2 Hypothesis “The Scientific Method” Hypothesis- Is a suggested answer to a well-defined scientific question or an explanation on trial.

Scientific Method

Scenario It’s late at night and you hear thunder and rain. Wind begins to pick up and you see a tree fall. Your power goes out. What do you reach for? A. Flashlight The flash light does not work!

Scenario What is our observation? Flashlight does not work. What is our question? What’s wrong with the flashlight? What is our hypothesis? The batteries are dead.

Scenario What is our prediction? If the batteries are dead and we replace them, the flashlight will work. What is our test? Replace the batteries.

Scenario Summary

Designing a Controlled Experiment Variable- A condition that can differ within the experiment. Controlled Experiment- An experiment that tests the effect of a single variable.

Case Study Snakes Many poisonous animals are brightly colored with distinctive patterns. There are also mimics. Coral snake (poisonous) Scarlet king snake (Not p)

What is the function of mimicry? What kind of experiment can you design to find the function of mimicry?

Observation? Both types of snakes have red, yellow, and black rings. Question? What is the function of the kingsnakes’ mimicry of coral snakes? Hypothesis? Mimicry of coral snakes helps protect the kingsnake from predators.

Prediction? If predators confuse the kingsnakes with coral snakes, then predators should attack fewer ringed snakes than brown artificial snakes. Experiment? Scientists place brown artificial snakes in forest and see how many attack it gets from predators compared to ringed snake.

Scientific method gone wrong! Observation: Village thinks a woman is a witch. Question: Is she a witch?!

Hypothesis: “If she weighs the same as a duck, then she’s made of wood, therefor SHE’S A WITCH!” Test: “She’s a witch, burn her!”

2.3 Understanding Science Are these figures real? What do you need to prove that they are real?

Evidence Evidence- Consists of a collected body of data from observations and experiments. Theory- A well-tested explanation that makes sense of a great variety of scientific observations.

Hypothesis vs Theory Hypothesis- “Mimicking poisonous snakes is an adaptation that protects nonpoisonous snakes from predators.” Theory- “Adaptations such as mimicry evolve by natural selection.” Only become theory with extensive supporting research!

Models Models- Are physical, mental, or mathematical representations of how people understand of process an idea. Ex. Drawings, graphs, 3 dimensional objects, computer program.

Blood Flow Model

Science, Technology, and Society Technology- Apply scientific understanding for some specific purpose. Microscope? Observe microorganisms Stem cell research? Prevent heritable disease