1-Cell Biology

Question 1

What is the difference between a Eukaryotic cell and a prokaryotic cell?

Answer 1

*Eukaryotic cells have a cell membrane,
cytoplasm and genetic material enclosed in a nucleus *prokaryotic cells are much smaller and have cytoplasm and a cell membrane surrounded by a cell wall,
*genetic material is not enclosed in a nucleus It is a single DNA loop and may contain small rings of DNA called plasmids.

Question 2

Compare the size of Prokaryotic and Eukaryotic cells.

Answer 2

Prokaryotic cells range from 0.1 to 5.0 micrometers (μm) in diameter and Eukaryotic cells have diameters ranging from 10 to 100 μm and are 100-10,000 times larger.

Question 3

What do all animal cells contain?

Answer 3

• a nucleus
• cytoplasm
• a cell membrane
• mitochondria
• ribosomes.

Question 4

What do plant cells contain in addition to animal cells?

Answer 4

• Chloroplasts
• Permanent vacuole filled with cell sap.
• Cell wall

Question 5

What is the role of the nucleus?

Answer 5

enclose genetic information.

Question 6

What is the role of the cytoplasm?

Answer 6

• Where most chemical reactions happen
• Contains enzymes that control these reactions.

Question 7

What is the role of the cell membrane?

Answer 7

Holds the cell together and controls what goes in and out.

Question 8

What is the role of the mitochondria?

Answer 8

• Site of cellular respiration
• Releases energy for the cell to work.

Question 9

What is the role of ribosomes?

Answer 9

Where proteins are made in the cell.

Question 10

What is the role of the cell wall?

Answer 10

• Made of cellulose
• Support and strengthen the cell.

Question 11

What is the role of the vacuole?

Answer 11

• Contains cell sap
• Weak solution of sugar and salts.

Question 12

What is the role of Chloroplasts?

Answer 12

Contains chlorophyll for photosynthesis, which makes food for the plants.

Question 13

Name 5 specialised plant cells.

Answer 13

• Root hair cells
• Xylem
• Phloem
• Guard cells
• Placide leaf cells

Question 14

Name 5 specialised animal cells.

Answer 14

• Sperm cells
• Egg cells
• Nerve cells
• Muscle cells
• Red blood cells

Question 15

What is cell differentiation?

Answer 15

• When an organism develops
• Cells differentiate to form different types of cells.

Question 16

Whats the difference in when animal and plant cells differentiate?

Answer 16

• Most animal cells differentiate at an early stage of life
• Many plant cells retain the ability to differentiate throughout life.

Question 17

What are the advantages of using a light microscope?

Answer 17

• Can view live structures
• Let us see individual cells and large subcellular structures like nuclei

Question 18

What are the advantages of using an electron microscope?

Answer 18

Much higher resolution so clearer image.

Question 19

What is the formula for magnification?

Answer 19

magnification=image size/real size

Question 20

What are chromosomes?

Answer 20

Coiled up lengths of DNA molecules

Question 21

How many chromosomes do human cells contain?

Answer 21

46, 23 pairs

Question 22

What is the first stage of the cell cycle?

Answer 22

*Cell grows and increases the amount of sub-cellular structures such as mitocondria and ribosomes
*Duplicates DNA so there’s one copy for each new cell

Question 23

What is the second stage of the cell cycle?

Answer 23

*Mitosis
*Chromosomes pulled to each end of the cell and the nucleus divides

Question 24

What is the final stage of the cell cycle?

Answer 24

*Cytoplasm and cell membrane divide to form two identical cells

Question 25

Why is cell division via mitosis improtant?

Answer 25

*For growth and developmentof multicellular organisms

Question 26

What is diffusion?

Answer 26

The movement of particles across the cell membranes from an area of higher concentration to an area of lower concentration

Question 27

What factors affect diffusion?

Answer 27

*Concentration gradient
*Temperature
*The surface area of the membrane

Question 28

How does concentration affect diffusion?

Answer 28

The steeper the concentration, the faster the rate of diffusion

Question 29

How does temperature affect rate of diffusion?

Answer 29

As temperature increases so does kinetic energy in the cells, so particles speed up and mix more quickly

Question 30

How does surface area affect rate of diffusion?

Answer 30

As surface area increases, so does rate as there is more space for particles to diffuse across the membrane

Question 31

What is osmosis?

Answer 31

The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane

Question 32

What is active transport?

Answer 32

The movement of substances against a concentration gradient Which requires energy from respiration

Question 33

Describe the multiplication of bacteria?

Answer 33

Bacteria multiple by binary fission (simple cell division), as often as once every 20 minutes

Question 34

How can bacteria be grown?

Answer 34

A nutrient broth solution or as colonies on an agar gel plate

Question 35

What is required for investigating the actions of disinfectants and antibiotics?

Answer 35

Uncontaminated cultures of microorgamisms

Question 36

-What is an enzyme?

Answer 36

A biological catalyst

Question 37

How do enzymes increase rate of reaction?

Answer 37

• Biological catalysts
• Provide an alternative shorter pathway for reaction