B1.1-Cell structure

Question 1

What are three common features of plant and animal cells (eukaryotes)?

Answer 1

1) Cell membrane; 2) Cytoplasm; 3) Genetic material in a nucleus.

Question 2

Which are bigger; bacterial cells (prokaryotes) or eukaryotes?

Answer 2

Eukaryotes.

Question 3

True or false? “Prokaryotic cells have a cell wall.”

Answer 3

True.

Question 4

True or false? “Prokaryotic cells have a nucleus.”

Answer 4

False.

Question 5

In what form is the genetic material in a prokaryotic cell?

Answer 5

A single DNA loop.

Question 6

Name five common parts of animal and plant cells.

Answer 6

Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes

Question 7

Name two further features of a plant cell.

Answer 7

Chloroplasts, permanent vacuole (filled with cell sap).

Question 8

Describe the function of the nucleus.

Answer 8

Contains the genetic material of the cell.

Question 9

Describe the function of the cytoplasm.

Answer 9

The location of cellular reactions.

Question 10

Describe the function of the cell membrane.

Answer 10

To determine what is allowed into and out of the cell.

Question 11

Describe the function of the mitochondria.

Answer 11

Where aerobic respiration occurs to release energy.

Question 12

Describe the function of the ribosomes.

Answer 12

To bond amino acids together to form proteins (protein synthesis).

Question 13

Describe the function of the chloroplasts.

Answer 13

The location of photosynthesis.

Question 14

Describe the function of the permanent vacuole.

Answer 14

A storage area for ions and water, sometimes pigments.

Question 15

Which strong material is the cell wall of plant and algal cells made from?

Answer 15

Cellulose.

Question 16

What is the definition of a cell?

Answer 16

The individual unit of an organism.

Question 17

What is the definition of a tissue?

Answer 17

Cells of the same type working together to perform a specific function.

Question 18

What is the definition of an organ?

Answer 18

A structure made from multiple tissue types to perform a specific function.

Question 19

What is the definition of an organ system?

Answer 19

Multiple organs working together to perform a specific function.

Question 20

Describe a specialisation of a sperm cell.

Answer 20

Mobile due to flagellum; many mitochondria to allow high energy release for movement; streamlined head; digestive enzymes in head to break down egg membrane.

Question 21

Describe a specialisation of a nerve cell.

Answer 21

Many mitochondria to provide lots of energy for active transport; many proteins embedded in cell membrane to allow ion movement.

Question 22

Describe a specialisation of a muscle cell.

Answer 22

Many mitochondria to provide lots of energy for contraction; many ribosomes to synthesise proteins.

Question 23

Describe a specialisation of a root hair cell.

Answer 23

Elongated shape to increase surface area for ion absorption; many mitochondria to provide lots of energy for active transport.

Question 24

Describe a specialisation of a xylem cell.

Answer 24

Little cell contents to allow easy movement of water and ions through each cell.

Question 25

Describe a specialisation of a phloem cell.

Answer 25

Needs a companion cell to work optimally.

Question 26

What is “cell differentiation”?

Answer 26

The process of a stem cell dividing and becoming a specialised cell.

Question 27

When do most animal cells differentiate?

Answer 27

At an early stage of development.

Question 28

What is different about plant cells’ differentiation?

Answer 28

They retain the ability to differentiate throughout life (e.g. a stem developing roots when planted in soil)

Question 29

In mature animals, what is cell differentiation used for?

Answer 29

Repair and replacement of old/damaged cells.

Question 30

What are the two advantages of electron microscopes over light microscopes?

Answer 30

1. Increased magnification, 2. Increased resolution.

Question 31

What is the “resolution” or “resolving power” of a microscope?

Answer 31

The ability to determine two close objects as separate images.

Question 32

What are the three forms of equation used to calculate magnification (M), the image size (I) or the actual size of an object (A)?

Answer 32

1. A=I/M, 2. I=A x M, 3. M=I/A

Question 33

What is 1340000 nm expressed in standard form?

Answer 33

1.34 x 10^6 nm

Question 34

What is 0.0000001 µm expressed in standard form?

Answer 34

1 x 10-7 µm

Question 35

What is the difference between mm, µm and nm?

Answer 35

A factor of 1000.

Question 36

By what process do bacterial cells divide?

Answer 36

Binary fission.

Question 37

If provided with enough nutrients and a suitable temperature, how often can bacterial cells divide?

Answer 37

Around every 20 minutes.

Question 38

Describe the two ways bacteria can be grown in a laboratory.

Answer 38

1. In a nutrient broth solution, 2. On an agar gel plate/petri dish.

Question 39

What is a “contaminant”?

Answer 39

An unwanted species of microorganism growing in your culture.

Question 40

What should you do with Petri dishes and culture media before use?

Answer 40

Sterilise it at high temperature to kill contaminants.

Question 41

How do you sterilise inoculating loops?

Answer 41

Pass them through a Bunsen burner flame before use.

Question 42

How should a Petri dish be stored in school?

Answer 42

Upside down, with tape securing the lid.

Question 43

What is the maximum temperature cultures should be incubated at in schools or colleges?

Answer 43

25°C

Question 44

Explain why the maximum incubation temperature for bacterial cultures in schools is 25⁰C.

Answer 44

To avoid growing potential pathogens.

Question 45

If you were asked to calculate the cross-sectional area of a circular clear area around a disinfectant, what equation would you use?

Answer 45

Pi r^2

Question 46

What is a chromosome?

Answer 46

A coiled thread-like structure of nucleic acids (DNA) and protein found in the nucleus of eukaryotic cells.