Chapter 3

Question 1

Define the following terms:

1. Ecology
2. Matter
3. Elements

Answer 1

1. Is the scientific study of the relationship between organisms and their environment.
2. Everything that has mass and takes up space. (Solid, liquid, gas, plasma). Matter is neither
   created or destroyed, it is recycled over and over again.
3. Substances that cannot be broken down into simpler forms by ordinary chemical reactions.

Question 2

Define the following terms:

1. Atom
2. Atomic Number
3. Isotope
4. Compound

Answer 2

1. Are the smallest particles that exhibit the characteristics of an element.
2. Is the number of protons per Atom in an element.
3. Forms of an element differing in atomic mass (sum of protons and neutrons). An Isotope possesses varying number of Neutrons
4. Substance composed of different kinds of atoms.

Question 3

What is an Atom comprised of?

Answer 3

Protons, Neutrons, Electrons

Question 4

What is the difference between an atom and an isotope?

Answer 4

1. Atoms are the smallest particles that exhibit the characteristics of an element.
2. Isotopes are forms of an element that differ in atomic mass.

Question 5

What is the difference between Ionic bond and Covalent bond?

Answer 5

1. Ionic Bond is where Atoms with opposite charges form a bond
2. Covalent Bond is where Atoms share electrons (but not always equally)

Question 6

1. A substance that has a PH value of 6 and under is..?

2. A substance that has a PH of 8 and over is..?

Answer 6

1. Acidic

2. Basic

Question 7

What do all organic compounds contain?

Answer 7

Carbon

Question 8

What is an Enzyme?

Answer 8

A Molecular catalyst regulating chemical reactions. Enzymes are usually proteins.

Question 9

What is:

1. Energy
2. Kinetic Energy
3. Potential Energy
4. Chemical Energy
5. Heat

Answer 9

1. Energy is the ability to do work
2. Kinetic Energy is energy in moving objects
3. Potential Energy is stored energy
4. Chemical Energy is stored in the food that you eat and the gasoline that you put into your car
5. is Energy that can be transferred between objects of different temperature. When a substance
   absorbs heat, the motion of its molecules increases and it may change state (e.g., a liquid may become a
   gas). Evaporation and condensation distribute heat around the globe.

Question 10

What are the First and Second Laws of Thermodynamics?

Answer 10

1. First Law is that Energy is neither created nor destroyed (it is conserved).
2. Second Law is that With each successive energy transfer, less usable energy is available to perform
   work.

Question 11

What is Photosynthesis?

Answer 11

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical
energy that can later be released to fuel the organisms’ activities.

In photosynthesis, energy is captured. In respiration, energy is released.

Question 12

What percentage of light that falls on plants is captured for Photosynthesis?

Answer 12

1 - 2%

Question 13

What is the equation for photosynthesis?

Answer 13

6H20 + 6CO2 + solar energy = C6H12O6(sugar) + 6O2

Water + Carbon Dioxide + Energy = Sugar + Oxygen

Question 14

What is the equation for cellular respiration?

Answer 14

C 6 H 12 O 6 + 6 O 2 = 6 H 2 O + 6 CO 2 + energy

Question 15

What is Trophic level? What are Herbivores, Carnivores, Omnivores, Detritivores, Scavengers, and
Decomposers?

Answer 15

1. Trophic Level is an organism’s feeding status in a food web. Plants are at the producer level while
   animals are the consumers.
2. Herbivores are plant eaters
3. Carnivores are flesh eaters
4. Omnivores eat both plant and animal matter
5. Detrivores such as ants and Beatles consume litter, debris, and dung
6. Scavengers are Crows, Jackals, and vultures clean up dead carcasses
7. Decomposers are Fungi, bacteria, complete the final breakdown of recycling of organic materials.

Question 16

What are considered to be producers, primary, secondary and tertiary consumers?

Answer 16

1. Producers Are organisms that photosynthesize, mainly green plants and algae.
2. Primary Consumers Are animals that eat plants
3. Secondary Consumers Are animals that eat other animals
4. Tertiary Consumers Are top animals that eat other animals (Top Carnivores)

Question 17

What is the 10% rule?

Answer 17

The rule states that only about 10% of the energy in one Trophic level is represented in the next higher
level.

Question 18

What continually evaporates water stored in oceans and on land and distribute
water vapor around the globe?

Answer 18

Solar Energy

Question 19

Hydrological cycle is responsible for what functions?

Answer 19

1. C metabolism
2. Nutrient flow in ecosystems
3. Global distribution of heat and energy.

Question 20

Explain carbon cycle. Also what is a carbon sink?

Answer 20

1. The series of processes by which carbon compounds are interconverted in the environment, involving the incorporation of carbon dioxide into living tissue by photosynthesis and its return to the atmosphere through respiration, the decay of dead organisms, and the burning of fossil fuels.
2. Carbon Sinks Are the parts of the cycle that remove carbon dioxide from the atmosphere (live
   vegetation) .

Question 21

Explain the Nitrogen Cycle

Answer 21

Nitrogen is needed to make proteins and nucleic acids such as DNA. Plants take up inorganic nitrogen from the environment and build protein molecules which are later eaten by consumers.

Nitrogen-fixing bacteria change nitrogen to a more useful form by combining it with hydrogen to make ammonia. Other bacteria convert ammonia to nitrites and nitrates, which can be taken up by plants to make proteins. Nitrogen re-enters the environment: Death of organisms; Excrement and urinary wastes

Question 22

Explain the Phosphorus Cycle

Answer 22

Phosphorous is needed to make DNA, ATP (the energy currency of the cell) and other important biomolecules. Phosphorous compounds are leached from rocks and minerals and usually transported in aqueous form.

Taken in and incorporated by producers Passed on to consumers. Returned to environment by decomposition. Cycle takes a long time as deep ocean sediments are significant sinks