WEEK 7

Question 1

What is cytology?

Answer 1

The study of cells, including their structure, function, and chemistry.

Question 2

Describe cell theory.

Answer 2

All living things are made of cells.
* The cell is the basic unit of life.
* All cells come from pre-existing cells.

Question 3

What is differentiation?

Answer 3

The process by which a cell becomes specialized for a specific function.

Question 4

Why are most cells small?

Answer 4

Cells must remain small to maintain a high surface area to volume ratio, which allows efficient nutrient uptake and waste removal.

Question 5

What limits the size of a cell?

Answer 5

Diffusion limits cell size.

Question 6

How does the rate of diffusion change for a cell with a large SA:Vol ratio?

Answer 6

Faster diffusion.

Question 7

How does the rate of diffusion change for a cell with a small SA:Vol ratio?

Answer 7

Slower diffusion.

Question 8

Why aren’t we all microscopic?

Answer 8

Multicellularity allows organisms to grow large while keeping individual cells small and efficient.

Question 9

Describe a prokaryotic cell.

Answer 9

Small, simple cells without a nucleus or membrane-bound organelles (e.g., bacteria).

Question 10

Describe a eukaryotic cell.

Answer 10

Larger, complex cells with a nucleus and membrane-bound organelles (e.g., animal and plant cells).

Question 11

What is the advantage of internal cellular compartments?

Answer 11

Allows specialization of functions and increased efficiency.

Question 12

What are the four characteristics all cells share?

Answer 12

Plasma membrane
* Cytoplasm
* Ribosomes
* DNA

Question 13

What is the cytoplasm?

Answer 13

The entire contents within the cell membrane, excluding the nucleus.

Question 14

What is the cytosol?

Answer 14

The fluid portion of the cytoplasm; excludes organelles.

Question 15

What is the cytoskeleton?

Answer 15

A network of fibers providing structural support, transport, and cell movement.

Question 16

What are microfilaments?

Answer 16

Thin filaments made of actin that support cell shape and movement.

Question 17

What are intermediate filaments?

Answer 17

Stable fibers that reinforce cell shape and anchor organelles.

Question 18

What are microtubules?

Answer 18

Hollow tubes that maintain cell shape and are involved in transport and cell division.

Question 19

What is a centriole?

Answer 19

A structure that helps organize microtubules during cell division.

Question 20

What is an organelle?

Answer 20

Specialized structures within cells; can be membrane-bound (e.g., mitochondria) or non-membrane-bound (e.g., ribosomes).

Question 21

What is the nucleus?

Answer 21

The control center of the cell; contains DNA.

Question 22

Describe the structure of the nuclear envelope and pores.

Answer 22

Double membrane with nuclear pores that regulate entry/exit of materials.

Question 23

What is the nucleolus?

Answer 23

Region within the nucleus where ribosomal RNA is made.

Question 24

What is the endoplasmic reticulum (ER)?

Answer 24

A network for protein and lipid synthesis; continuous with the nuclear envelope.

Question 25

What is the difference between rough and smooth ER?

Answer 25

Rough ER has ribosomes; makes proteins. * Smooth ER lacks ribosomes; makes lipids and detoxifies.

Question 26

What is a ribosome?

Answer 26

A structure that synthesizes proteins.

Question 27

What is the structure and function of the Golgi complex?

Answer 27

Stacks of membranes that modify, package, and ship proteins and lipids.

Question 28

What is a transport vesicle?

Answer 28

Small membrane-bound sacs that transport substances in the cell.

Question 29

What is a lysosome?

Answer 29

Contains digestive enzymes; involved in autophagy and breaking down macromolecules.

Question 30

What is the mitochondria?

Answer 30

The powerhouse of the cell; site of cellular respiration (ATP production).

Question 31

What are the differences between animal and plant cells?

Answer 31

Plant cells have chloroplasts, a cell wall, and large central vacuole. * Animal cells have centrioles and lysosomes.

Question 32

What is the function of a chloroplast?

Answer 32

Conducts photosynthesis to convert sunlight into chemical energy.

Question 33

What are the functions of a large central vacuole?

Answer 33

Stores water and nutrients; provides structural support.

Question 34

Describe a cell wall.

Answer 34

Rigid structure outside the cell membrane in plants, fungi, and some prokaryotes; provides support and protection.

Question 35

What is cell division?

Answer 35

Process of producing new cells.

Question 36

Why do cells divide?

Answer 36

Single-celled organisms divide to reproduce. * Multicellular organisms divide for growth, repair, and development.

Question 37

How do prokaryotic cells divide?

Answer 37

Binary fission – cell duplicates DNA, grows, and splits into two.

Question 38

Why is eukaryotic cell division more complicated?

Answer 38

They have multiple chromosomes and organelles that must be duplicated and divided correctly.

Question 39

What are the two types of cell division in humans?

Answer 39

Mitosis (growth, repair) * Meiosis (produces gametes for reproduction).

Question 40

What is the cell cycle?

Answer 40

The repeating series of events in a cell’s life: growth, DNA replication, and division.

Question 41

What are the two main phases of the cell cycle?

Answer 41

Interphase: Cell grows, DNA replicates. * M phase: Cell divides.

Question 42

What are the three subphases of interphase?

Answer 42

G1: Cell grows. * S: DNA replicates. * G2: Prepares for mitosis.

Question 43

Describe M phase.

Answer 43

Includes mitosis (nuclear division) and cytokinesis (cytoplasm division).

Question 44

What are the subphases of M phase?

Answer 44

Prophase, Metaphase, Anaphase, Telophase, Cytokinesis.

Question 45

What is the end result of mitosis?

Answer 45

2 identical daughter cells.

Question 46

What is the end result of meiosis?

Answer 46

4 genetically unique daughter cells with half the DNA.

Question 47

What is G0 phase?

Answer 47

A resting state where the cell exits the cycle and does not divide.

Question 48

What conditions lead to cell division?

Answer 48

Cells divide when: Nutrients are available, signals are received, DNA is intact.

Question 49

What conditions lead to a halt in cell division?

Answer 49

Cells do not divide when: DNA is damaged, signals are absent, or checkpoints fail.

Question 50

What regulates the cell cycle?

Answer 50

Checkpoints with proteins and enzymes ensure the cycle proceeds correctly.

Question 51

What does the G1 checkpoint check?

Answer 51

Checks size, nutrients, DNA.

Question 52

What does the G2 checkpoint ensure?

Answer 52

Ensures DNA is fully replicated.

Question 53

What does the M checkpoint check?

Answer 53

Checks spindle attachment to chromosomes.

Question 54

What happens if something is wrong at a checkpoint?

Answer 54

The cell cycle stops for repair or triggers cell death (apoptosis).

Question 55

What is cancer?

Answer 55

Uncontrolled cell growth due to mutation or failed regulation.

Question 56

How does cancer occur?

Answer 56

Due to failed regulation of the cell cycle.