Scientific method– Independent variable – stand alone variable that you

manipulate during an experiment (ex – number of days)

– Dependent variable – depends on independent variable & what you collect data on in an experiment (ex – growth of yeast population)

– You perform an experiment to identify the effect of time spent studying on test scores. What are the independent and dependent variables?

Independent and DependentThe effect of fertilizer on tomato plant growth: 20

tomato plants were divided into 2 groups of 10 each. One group was grown in soil treated with fertilizer; the other group was grown in soil that wasn’t treated with fertilizer. The height of the tomato plant was measured at the end of the growing season.

The effect of sleep deprivation on memory: 50 people we divided into 2 groups of 25 each. One group was allowed 9 hours of sleep a night for 1 week. The other group was allowed only 6 hours of sleep a night for 1 week. Each group was given a memory test at the end of the week and scores were calculated.

And some more practice…Effect of a high carbohydrate diet on running

speed: 30 runners were divided into 2 groups of 15 each. One group was served a large pasta dinner every night for 1 week. The other group was served a small pasta dinner every night for 1 week. At the end of the week, both groups ran 3 miles and times were recorded.

Effect of sun on aging: the number of premature wrinkles for 2 groups of people age 40 was counted and recorded. One group reported spending many hours in the sun while the other group did not.

Key Components of a GraphTitle Axis labels (with units!)Even scaleConnected points (on line graph)

Graphing Independent & Dependent variables

X axis = independent Y axis = dependent

Bar Graph or Line Graph?

Bar if… Line if… Data is in distinct

categories (only ½ the data is in numbers) ie foods, months etc.

You are NOT going to use the graph to make predictions about other data points

Data is not continuous

Data has anything to do with something over time

You need to show the relationship between independent and dependent experimental variable

To predict unknown data points

Bar or Line? An experiments measuring the growth of a tortoise

shell (in mm) over the age of the tortoise (in years).

An experiment that compares the sources of fat (saturated, unsaturated and trans fat) in grams/tablespoon for butter, margarine and olive oil.

An experiment that compares the percentage physical activity between males and females in 9th, 10th, 11th and 12th grade.

An experiment that compares the breathing rate of fish (per minute) as temperature increases.

TROPHIC LEVELSIdentify the following from the food web

below: Producer First level consumer (herbivore) Second level consumer (carnivore) Third level consumer

Food Web Details & Understanding?

Identify a food chain from the web below.Which organism consumes food from

multiple trophic levels? Which food chain containing that animal

obtains the most energy from the sun? Make the that chain into an energy

pyramid

Tertiary Consumer: Hawk (.1%)Secondary

Consumers: Lizard & Snake

(1%)

Primary Consumers: Mouse, Grasshopper & Rabbit

(10%)

Primary Producers: Grass (100%)

If a toxic chemical were used on the grass, which organism would accumulate the most?

Why? What is this called?

Hawk 1%

Rabbit/Mouse/

Grasshopper 10%

Grass 100%

Mos

t en

ergy

efficien

t!

What is the difference between osmosis and diffusion? Osmosis = movement of water from high

concentration to low concentration

Diffusion = movement of small molecules other than water from high concentration to low concentration

Practice Strawberry jelly is a very strong solution of

sugar. By contrast the cytoplasm in a bacteria is a much weaker solution.

The cell wall of a microbe is made up of a semi-permeable membrane. Would water flow from the microbe to the jam, or from the jam to the microbe by osmosis?

Explain why bacteria find it difficult to survive in jam.

What happens to the number of water particles on the left hand side?

What happens to the concentration of the solute on the right hand side?

What happens to the concentration of the solute on the left hand side?

Explain why the concentrations of solute on either side of the semi-permeable membrane change?

Inheritance Patterns Simple dominance – if one dominant allele is

present, it shows.

Incomplete dominance – heterozygous organism is a blend of the two possible phenotypes … EXAMPLES??

Codominance – heterozygous organism shows both possible phenotypes at the same time … EXAMPLES?

Incomplete or codominance? Birds can be blue, white, or

white with blue-tipped feathers.

Flowers can be white, pink, or red.

A Who can have curly hair, spiked hair, or a mix of both curly and spiked.

A Sneech can be tall, medium, or short.

A Bleexo can be spotted, black, or white.

Cross a blue feathered with a white with blue-tipped feathered bird.

Cross a white flower with a red flower.

Cross a curly haired Hoo with a spiked hair Hoo.

Cross a medium Sneech with another medium Sneech.

Cross a spotted Bleexo with a white bleexo.