What do you Remember?

Concepts from Grades 9 & 10 ANSWERS

1. What is biodiversity?

The number of different living organisms in a given area.

2. A homeowner dislikes the dandelions and weeds in his front yard. He wants lush green grass for his children to play on. He decides to use pesticides to eliminate the weeds. Critique (positives & negatives) his decision to use pesticides. What alternative actions could the homeowner take?

POSITIVES

- Pesticides get rid of weeds.

NEGATIVES

- Pesticides can run-off & pollute groundwater.

ALTERNATIVES – Pull weeds out by hand.

3. The ecological footprint of all humanity has been calculated to be equal to 1.3 Earths. What does this mean?

- If we continue to use resources like we do, we will need 1.3 Earths to support humanity.

- We do not have 1.3 Earths. We have 1.

4. Of the following organisms, which one is a decomposer?

b) Fungi

5. What is a cell?

- A membrane enclosed structure, which is the basic functional unit of life.

6. List seven (7) various organelles that make up a cell. Briefly discuss each organelle’s function.

Nucleus – contains DNA & controls cell’s activities.

Mitochondria – gives cell energy

Cell membrane – lets things in & out of the cell.

Ribosome – makes proteins

Cytoplasm – lets things move around in cell

Endoplasmic reticulum – transports Materials (e.g. Proteins) around cell

Lysosome – breaks down molecules

7. Complete the Venn diagram below to show the contrast between an animal & a plant cell.

Similarities - both are enclosed by a membrane, both function to build tissues/systems to support the organism.

Differences - Plant cell has cell wall & chloroplast (which animal cells do not have). - Animal cell has centrioles used in cell division (which plant cells do not have)

8. Describe the points of cell theory.

1) All living things are composed of cells

2) Cells come from pre-existing cells

3) Cells are the basic functional unit of life.

9. a) What is the cell cycle?= A series of events that take place in a cell leading up to its division.

9. b) Draw the cell cycle & briefly explain the part of each cycle.

10. What is the process of cell division called? Briefly outline the steps of this process.

Mitosis

Interphase – cell prepares to divide (increases in size & copies/duplicates its DNA)

Prophase – DNA condenses into a highly organized structure called chromosomes

Metaphase – chromosomes line up along the equator

Anaphase – spindle fibers help to pull apart the chromosomes to opposite sides of the cell.

Telophase – nucleus reforms in ‘daughter’ cells, two daughter cells produced.

11. Complete the following chart comparing asexual & sexual reproduction.

12. Complete the chart below about the human body organ systems.

13. Provide three (3) tips to help maintain healthy organ systems.

- Exercise, eat healthy, don’t smoke

14. a) What is photosynthesis? = the ability of a plant to produce sugar from sunlight & carbon dioxide.

14. b) Write out the word equation.

Water + Sun + Carbon Dioxide Sugar + Oxygen

14. c) Where does photosynthesis occur?The chloroplast of a plant cell

15. a) What is cellular respiration?= the breakdown of sugars to produce energy.

15. b) Write out the word equation.

Sugar + Oxygen Energy + Carbon Dioxide + Water

15. c) Where does cellular respiration occur?

The mitochondria of an animal cell