Download Unit 1: The Study of Life Review Questions ANSWERS

Unit 1: The Study of Life Review Questions ANSWERS
1. What are the 8 characteristics of life and list an EXAMPLE of each.
(1) Made up of cells
Example: Humans are multicellular but some organisms are made up of
only one cell.
(2) Reproduce
Example: Maple trees reproduce sexually but hydras can reproduce
asexually by budding.
(3) Based on a universal genetic code (DNA)
Example: Flies produce flies, humans produce humans, maple trees
produce maple trees.
(4) Grow and develop
Example: Flies begin life as eggs, then become maggots, then adult flies.
(5) Use/need energy
Example: Plants obtain their energy from sunlight and animals from the
food they eat.
(6) Respond to their environment (stimuli)
Example: Leaves and stems of plants grow towards light.
(7) Maintain a stable internal environment (homeostasis)
Example: Despite changes in outside temperature, a robin maintains a
constant body temperature.
(8) Adapt and evolve
Example: Plants that live in the desert survive because they become
adapted to the conditions of the desert.
2. What is biology? Study of life.
3. What must you make before you can state the problem when using the scientific
method? An observation
4. You must be able to test a hypothesis for it to be valid.
5. Define the following terms:
(1) Independent variable- Variable you are testing, the one you CHANGE (I change)
(2) Dependent variable- The one that responds to the IV, what you record data about
(3) Control group- The comparison group in an experiment, the most “normal”
(4) Constant- Factors that are kept the same in all experimental and control groups
6. Now use that knowledge to state the IV & DV in the scenarios below.
(1) The time it takes to run a kilometer depends on the amount of exercise a person gets.
IV: amount of exercise
DV: time it takes to run a kilometer
(2) The higher the temperature of water, the faster an egg will cook.
IV: temperature of water
DV: speed of egg cooking
(3) An investigation was done to see if keeping lights on for different amounts of time
each day affected the number of eggs chickens laid.
IV : amount of time light is kept on
DV: number of eggs chickens laid
(4) The temperature of water was measured at different depths of a lake.
IV: different depths of a lake
DV: temperature
(5) Grass will grow taller if you use fertilizer.
IV: use of fertilizer
DV: height of grass
(6) The amount of pollution produced by cars was measured for cars using gasoline
containing different amounts of lead.
IV _: amount of lead in gasoline
DV: amount of pollution produced by cars
(7) Lemon trees receiving the most water will produce the largest lemons.
IV : amount of water
DV: size of lemons
(8) Students who have high attendance rates will have higher grades.
IV: attendance rate
DV: grades