1.1 Cell Structure And Function

Question 1

What is an ideal plant tissue to examine under a 🔬 and why?

Answer 1

The onion epidermis is ideal because:

• Forms a layer just one cell thick
• Lacks chloroplasts, making it non-photosynthetic

Question 2

Why are human cheek cells suitable for 🔬examination?

Answer 2

• plentiful
• easy to obtain safely
• not overly intrusive
• relatively undifferentiated

Question 3

What are the safety precautions when preparing cheek cell samples?

Answer 3

DON’T PERFORM SAMPLING ON SOMEONE WITH:

• Cough
• Cold
• Throat infection
• Wear gloves when handling methylene blue as it is toxic if ingested

Question 4

What is the function of a mitochondria in a cell?

Answer 4

• Mitochondria are the site of aerobic respiration
• Mitochondria releases energy to the cell
• Mitochondria are abundant in metabolically active cells like muscle cells 💪

Question 5

What is the function of the cell membrane in a cell?

Answer 5

• The cell membrane holds the cell together
• The cell membrane controls which substances enter and leave
• The cell membrane separates the cell’s interior from its surroundings.

Question 6

What are ribosomes and where are they found in a cell?

Answer 6

Ribosomes are the site of protein synthesis and are found in the cytoplasm.

Question 7

What is the function of the nucleus in a cell?

Answer 7

The nucleus contains genetic material (DNA) which controls the activities of the cell

Question 8

What is the function of the cytoplasm?

Answer 8

The cytoplasm supports internal cell structures and is the site for many chemical reactions

Question 9

What is the cell wall made of and what is its function?

Answer 9

The cell wall is made of cellulose and provides extra support to the cell

Question 10

What are chloroplasts and their function?

Answer 10

Chloroplasts contain chlorophyll pigments, which absorb light energy during photosynthesis

Question 11

What is the function of the permanent vacuole?

Answer 11

The permanent vacuole contains cell sap (a solution of dissolved sugars and ions) used for storage and support of the cell structure

Question 12

Name the structures found in bacterial cells?

Answer 12

• Plasmids
• Cytoplasm
• Circular DNA
• Ribosomes
• Cell membrane
• Cell wall

Question 13

Describe the method to prepare a slide of human cheek cells for a 🔬exam?

Answer 13

• Brush teeth to remove bacteria
• Gently scrape the inside of the cheek with a sterile cotton swab
• Smear the swab on a microscope slide
• Add a drop of methylene blue solution
• Place a coverslip on the slide, laying it down to avoid air bubbles
• Use a paper towel to absorb excess solution
• Examine the slide under a microscope, starting with a 4x or 10x objective lens

Question 14

Compare the cell structures found in plant cells and bacterial cells

Answer 14

• Both have a cell wall and a cell membrane
• Plant cells have chloroplasts, mitochondria , a nucleus and a permanent vacuole.
• Bacterial cells have a circular DNA and plasmids

Question 15

What are the safety concerns when handling methylene blue, and how should they be addressed?

Answer 15

• Methylene blue is toxic if ingested
• To handle it safely, wear gloves and avoid contact with the mouth or ingestion
• Use it in a well-ventilated area and follow all safety protocols.

Question 16

What is cellulose made from

Answer 16

Carbohydrates

Question 17

2 Functions of root hair cell

Answer 17

• Absorption of water by Osmosis
• Absorption of mineral ions by Active Transport

Question 18

Describe how a root hair cell is adapted to its function

Answer 18

• They have profusion called root hairs which increase the surface area to volume ratio for absorption of water by osmosis and mineral ions by active transport.

Question 19

State the name of the structures that are not present in root hair cells and explain their function

Answer 19

• Chloroplasts
• that contain chlorophyll which traps light energy and converts it to chemical via photosynthesis