Required Practical 2

Question 1

What is the first step to prepare a microscope slide?

Answer 1

Take a thin slice or section of the sample.

Question 2

What do you do with the thin slice on the slide?

Answer 2

Place it on the slide with a small amount of water or solution/stain.

Question 3

What should you place on top of the slide?

Answer 3

Add a cover slip to the sample.

Question 4

What’s the purpose of placing a cover slip?

Answer 4

The cover slip prevents air bubbles and keeps the sample flat.

Question 5

How do you select cells for counting chloroplasts?

Answer 5

Select a large number of cells for a more accurate result.

Question 6

What’s the minimum number of cells you should select?

Answer 6

Select more than 5 cells.

Question 7

What’s the next step after selecting cells?

Answer 7

Count the number of chloroplasts in the selected cells.

Question 8

After counting chloroplasts, what do you do?

Answer 8

Divide the number of chloroplasts by the number of cells to get the average.

Question 9

Why must the sample be thin?

Answer 9

To allow more light to pass through for clear observation.

Question 10

How does having a thin layer of cells help?

Answer 10

A thin layer ensures that the stain penetrates better.

Question 11

Why do cells need to be spread out on the slide?

Answer 11

To prevent overlapping cells that would make it hard to view individual cells.

Question 12

What happens during cell division?

Answer 12

There is growth as the number of cells increases.

Question 13

What does cell division help with in the body?

Answer 13

It helps to repair and replace tissue or organs.

Question 14

What type of cells are produced in mitosis?

Answer 14

Mitosis produces genetically identical cells.

Question 15

What kind of reproduction does mitosis facilitate?

Answer 15

Mitosis is involved in asexual reproduction.

Question 16

Why is it important to select a large number of cells when counting?

Answer 16

It ensures a representative sample of the cell population.

Question 17

What does selecting a large number of cells improve?

Answer 17

It improves the reliability of the data.

Question 18

What happens in Metaphase?

Answer 18

Chromosomes align along the equator of the cell.

Question 19

What happens in Anaphase?

Answer 19

Sister chromatids are pulled apart to opposite sides of the cell.

Question 20

What shape do chromatids form in Anaphase?

Answer 20

Chromatids form a V-shape as they are pulled apart.

Question 21

How long does mitosis take in the observed cells?

Answer 21

2 hours (120 minutes) for mitosis to complete.

Question 22

How do you prepare a slide for microscopy?

Answer 22

Take a thin slice or section of the sample.

Question 23

What should you place on the slide with the sample?

Answer 23

Place a small amount of water or solution/stain on the slide.

Question 24

What should you do after placing the sample on the slide?

Answer 24

Add a cover slip to prevent air bubbles.

Question 25

How do you measure the size of an object in a microscope image?

Answer 25

1. **Measure the image length** in the field of view. 2. **Divide** by the **key length** for a scale.

Question 26

What should you multiply by after measuring the image?

Answer 26

Multiply by the **magnification factor** (e.g., 50).

Question 27

What is the acceptable size range for the measured object?

Answer 27

The size should be between **185-217 μm**.

Question 28

How do you calculate the number of chloroplasts in cells?

Answer 28

1. **Select a large number** of cells (e.g., more than 3). 2. **Count the number of chloroplasts**. 3. **Divide** the number of chloroplasts by the number of cells.

Question 29

Where are dividing cells found in plant tissue?

Answer 29

Dividing cells are found at the **root tip**.

Question 30

Why is the root tip used to observe mitosis?

Answer 30

The **root tip** is the area where **most active cell division** occurs.

Question 31

How do you calculate the percentage of cells in mitosis?

Answer 31

1. Count the number of cells in **anaphase**. 2. **Divide** by the total number of cells, then multiply by 100 to get the percentage.

Question 32

What is the result when you calculate the mitosis percentage?

Answer 32

The result might be **around 9.4%** of cells in mitosis.

Question 33

What happens after mitosis in cell division?

Answer 33

**Cytokinesis** occurs, splitting the cytoplasm.

Question 34

How can you improve the reliability of cell counting?

Answer 34

Examine a **large number of cells** (e.g., 20 or more).

Question 35

What else can you do to improve reliability in cell counting?

Answer 35

**Repeat the count** to ensure consistency.

Question 36

How do you treat cells at the edge of the field?

Answer 36

**Exclude partial cells** at the edges of the field.

Question 37

What effect does a mitotic inhibitor have on cell division?

Answer 37

It **stops anaphase** and disrupts mitosis.

Question 38

How does a mitotic inhibitor affect spindle fibers?

Answer 38

It prevents the **formation of spindle fibers** or their attachment.

Question 39

What happens when spindle fibers are not formed in mitosis?

Answer 39

**Sister chromatids** cannot separate properly.

Question 40

What’s the result of no spindle fiber attachment in mitosis?

Answer 40

**No new cells** are produced.

Question 41

Where do dividing cells occur in plant tissues?

Answer 41

Dividing cells are located near the **root tip**.

Question 42

How do you calculate the mitosis percentage from observations?

Answer 42

1. Count the cells in **anaphase** (e.g., 3). 2. Calculate the percentage (e.g., **3.57%**).

Question 43

What’s the last stage of cell division after mitosis?

Answer 43

**Cytokinesis** is the final stage.

Question 44

How can you ensure your counting is representative in mitosis?

Answer 44

1. **Examine a large number** of cells (e.g., 20+). 2. **Repeat** the counts for consistency.

Question 45

How do mitotic inhibitors affect the cell cycle?

Answer 45

1. They **stop anaphase** and cell division. 2. They **disrupt spindle fibers**, preventing chromatid separation. 3. **No new cells** are created.

Question 46

Where does mitosis occur in plants?

Answer 46

Mitosis occurs at the **root tip**.

Question 47

Why must chromosomes be stained in mitosis?

Answer 47

To make **chromosomes visible** under a microscope.

Question 48

Why should the sample be thin for observation?

Answer 48

So **light can pass through**, allowing you to see the cells.

Question 49

How do you calculate the percentage of cells in mitosis?

Answer 49

**Count cells** in **prophase** and **metaphase**, then calculate the percentage.

Question 50

What factors could influence mitosis rates?

Answer 50

**Genetic differences** and **environmental factors** like light, temperature, and nutrients.