Chp 1

Question 1

What does the cell membrane control?

Answer 1

The movement of substances going into and out of the cell.

Question 2

What are the three main processes by which substances move across the cell membrane?

Answer 2

• Diffusion
• Osmosis
• Active transport

Question 3

What do cells need to take in from the environment?

Answer 3

• Oxygen
• Glucose
• Amino acids

Question 4

What do cells release as waste products?

Answer 4

• Carbon dioxide (CO2)
• Urea

Question 5

Fill in the blank: The cell membrane can actively transport certain substances _______ and/or _______ of the cell.

Answer 5

[into] and/or [out]

Question 6

What structures are readily visible under a light microscope?

Answer 6

Nucleus, cell wall, cytoplasm, cell membrane, chloroplast

These structures can be observed using light microscopes due to their size and contrast.

Question 7

What structures can only be observed under an electron microscope?

Answer 7

RER, mitochondria, Golgi body, ribosomes, SER, vacuoles

Electron microscopes are required to visualize these smaller organelles and their substructures.

Question 8

Fill in the blank: An electron microscope can allow us to observe much smaller _______ and even their substructures.

Answer 8

[organelles]

Question 9

True or False: The cytoplasm is visible under both light and electron microscopes.

Answer 9

True

Cytoplasm is a large and prominent structure that is easily observable.

Question 10

Which organelle is known for energy production and is visible under an electron microscope?

Answer 10

[mitochondria]

Question 11

Fill in the blank: The _______ is a structure that is visible only under an electron microscope and is involved in protein processing.

Answer 11

[Golgi body]

Question 12

List three structures visible under a light microscope.

Answer 12

• Nucleus
• Cell wall
• Chloroplast

Question 13

What does RER stand for?

Answer 13

[Rough Endoplasmic Reticulum]

Question 14

True or False: Ribosomes are visible under a light microscope.

Answer 14

False

Ribosomes are too small to be seen with light microscopes and require electron microscopy.

Question 16

What is the process by which substances are transported against a concentration gradient?

Answer 16

Osmosis as it is substances not water particles

Question 17

What does ‘Endoplasmic’ and ‘reticulum’ mean?

Answer 17

‘Endoplasmic’ means within the cytoplasm, and ‘reticulum’ means network.

Question 18

What distinguishes Rough Endoplasmic Reticulum (RER) from Smooth Endoplasmic Reticulum (SER)?

Answer 18

Rough ER has numerous ribosomes attached to its membrane, giving it a rough appearance, while smooth ER does not have ribosomes.

Question 19

What is the relationship between the RER and the nuclear envelope?

Answer 19

The membrane of the RER is continuous with the nuclear envelope.

Question 20

What are ribosomes and what is their function?

Answer 20

Ribosomes are small structures made of RNA needed to synthesize proteins.

Question 21

What type of proteins do ribosomes attached to the RER produce?

Answer 21

They make proteins that are usually secreted out of the cell (via Golgi bodies).

Question 22

What do free ribosomes in the cytoplasm produce?

Answer 22

Free ribosomes make proteins that are used within the cell.

Question 23

What do ribosomes produce?

Answer 23

Ribosomes produce proteins.

Question 24

What does the smooth endoplasmic reticulum (SER) synthesize?

Answer 24

The SER synthesizes lipids and steroids, such as sex hormones, and detoxifies harmful substances.

Question 25

Where are SER abundantly found?

Answer 25

Glandular cells and liver cells have SER in abundance.

Question 26

What is the Golgi body also known as?

Answer 26

The Golgi body is also known as the Golgi apparatus.

Question 27

What does the Golgi body look like?

Answer 27

The Golgi body looks like a stack of flattened discs with vesicles merging into one side and budding off the other side.

Question 28

What is the main function of the Golgi body?

Answer 28

The main function of the Golgi body is to receive, modify, and sort substances (mainly proteins) made by the rough endoplasmic reticulum (RER), and then package them into vesicles for secretion out of the cell.

Question 29

What is the primary function of red blood cells (RBC)?

Answer 29

RBCs transport oxygen through the circulatory system, taking up oxygen in the lungs (or gills in fish) and releasing it into body tissues.

Question 30

What structural feature do mature red blood cells lack?

Answer 30

Mature red blood cells have no nucleus and other organelles.

Question 31

What is the shape of red blood cells?

Answer 31

Red blood cells have a biconcave disc shape.

Question 32

Why are red blood cells small and flexible?

Answer 32

Their small and flexible nature allows them to change shape and squeeze through narrow blood capillaries.

Question 33

What is the role of haemoglobin (Hb) in red blood cells?

Answer 33

Haemoglobin can bind oxygen reversibly in oxygen-rich environments (lungs) and unbind to release it in oxygen-poor environments (tissue cells in the body). ## Footnote Hb is a red coloured, iron-containing protein. Each RBC has about 270 million of them!

Question 34

How does the structure of red blood cells increase their oxygen carrying capacity?

Answer 34

The biconcave shape maximizes space to carry Hb molecules, hence increasing the total oxygen carrying capacity of each cell.

Question 35

How does the shape of red blood cells affect oxygen diffusion?

Answer 35

The increased surface area to volume ratio enhances the rate of oxygen diffusing into and out of the cell.

Question 36

What is a root hair?

Answer 36

A root hair is a structural feature of a plant root.

Question 37

What is a key characteristic of root hair cells?

Answer 37

Each root hair cell has a long and narrow extension.

Question 38

What is the significance of mitochondria in root hair cells?

Answer 38

Root hair cells contain many mitochondria to carry out aerobic respiration.

Question 39

What does magnification equal?

Answer 39

Magnification = image size / actual size.

Question 40

How is the structure of root hairs adapted for function?

Answer 40

Root hairs have a large surface area to volume ratio, increasing the rate of absorption of water and dissolved minerals from soil solution.

Question 41

Why do root hair cells carry out aerobic respiration?

Answer 41

To release a lot of energy for active transport of ions into the cell.

Question 42

What does maintaining a steep water potential gradient enable?

Answer 42

It enables continual osmosis of water into the cell.