Unit 1A - Cells, Scientific Method, Safety, Transport

Question 1

Homer notices that his shower is covered in strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water. After 3 days of the “treatement”, tehre is no change in the appearance of the green slime on either side of the shower.

Identify the control gorup, independent variable, dependent variable, and what the conclusion should be.

Answer 1

Control Group - the side of the shower sprayed with water

Independent Variable - which liquid was used for cleaning

Dependent Variable - whether or not the green slime went away

Conclusion - coconut juice does not get rid of green slime

Question 2

Bart believes that mice exposed to microwaves will become extra strong. He decides to perform this experiment by placing 10 mice in a microwave for 10 seconds. He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. He found that 8 out of 10 of the microwaved mice were able to push the block away and 7 out of the 10 non-microwaved mice were able to do the same.

Identify the control group, independent variable, dependent variable, and what the conclusion should be.

Answer 2

Control Group - non-microwaved mice

Independent Variable - the microwaves

Dependent Variable - mouse strength

Conclusion - the microwaves did not increase the strength of the mice to any noticeable degree

Question 3

How many variables do scientists test at a time?

Why?

Answer 3

Scientists test one variable at a time.

This allows them to isolate the variable and make sure that the effect observed in the experiment are the result of the one variable.

Question 4

Scientists publish their results in order to

Answer 4

1. Verify their procedures
2. Receive feedback
3. Verify their data

Question 5

Which is the smallest level of organization that includes living things?

Answer 5

Cells

Question 6

Of the following levels of organization, which level includes all of the other levels?

Cells, Ecosystem, Community, Organ System, Population

Answer 6

Ecosystem

Question 7

Name the 8 characteristics of living things

Answer 7

All living things:

1. Contain cells 2. Have DNA
2. Obtain and use energy
3. Reproduce 5. Respond to stimuli
4. Maintain homeostasis
5. Grow and develop 8. Evolve

Question 8

What is homeostasis? (be able to name examples of how organisms maintain this)

Answer 8

Maintaining relatively stable internal conditions

Question 9

Monosaccharides are monomers of

Answer 9

Carbohydrates

Question 10

Through what type of reaction are polymers of carbohydrates formed?

Answer 10

Dehydration Synthesis

Question 11

Nucleic Acids are made up of nucleotides, which include

Answer 11

A five-sided sugar, a phosphate, and a nitrogenous base

Question 12

The biomolecule responsible for heredity including hair color, skin color, eye color, etc., is

Answer 12

Nucleic Acids

Question 13

The long term energy source of living things is

Answer 13

Lipids (fats)

Question 14

Molecules that end in -ASE are

Answer 14

Proteins

Question 15

How do enzymes speed up the rates of reactions?

Answer 15

By lowering the activation energy

(the energy required for the reaction to take place)

Question 16

Bread, pasta, fruit, vegetables, and sugars are all examples of

Answer 16

Carbohydrates

Question 17

Which of the four biomolecules can you not obtain through food?

Answer 17

Nucleic Acids

Question 18

What is cell specialization?

Answer 18

Cells in a multicellular organism do different jobs

Question 19

Which scientists contributed to cell theory?

Answer 19

Schleiden, Schwann, and Virchow

Question 20

The three main components of cell theory are

Answer 20

1. All living things are made of cells
2. Cells are the basic unit of life
3. All cells come from existing cells

Question 21

How do specimen observe under a compound light microscope differ from an electron microscope?

Answer 21

Light - living

Electron - dead/nonliving

Question 22

Which organisms fall into the category of eukaryotes?

Answer 22

Protists, fungi, plants, and animals

Question 23

All prokaryotes are

Answer 23

Bacteria

Question 24

Compare and contrast prokaryotes and eukaryotes

Answer 24

Prokaryotes: no nucleus, older, all bacteria, smaller, simple, no membrane-bound organelles, unicellular

Eukaryotes: have a nucleus, have membrane-bound organelles, larger organisms than bacteria, contains unicellular and multicellular organisms (protists, fungi, plants, animals)

Question 25

Organelles found only in plants (not animals) include

Answer 25

Chloroplast - photosynthesis

Large Central Vacuole - turgor pressure

Cell Wall - ^^ and protection

Question 26

List the parts of the cell membrane and their function

Answer 26

Phospholipid - makes up the bilayer

Proteins - transport, recognition, attachment

Cholesterol - stabilizes the membrane and gives it more fluidity

Carbohydrates - recognition, signalling

Question 27

Why does diffusion occur?

Answer 27

Because of Brownian Motion (random movement of particles)

Question 28

Describe the three types of passive transport.

Answer 28

Diffusion - movement of substances from high concentration to low concentration across a semipermeable membrane

Osmosis - diffusion of water

Facilitated Diffusion - diffusion of large/polar molecules across a semipermeable membrane with the use of transmembrane proteins

Question 29

How do passive and active transport differ?

Answer 29

Passive transport does not require energy because it’s movement of particles with/down the concentration gradient (from high to low concentration)

Active transport does require energy because it’s movement of particles against the concentration gradient (from low concentration to high concentration)

Question 30

Lipids are composed of

Answer 30

A glycerol backbone and fatty acid chains (long chains of carbon and hydrogen)