Bio1 - Cell Biology

Question 1

Are Plant Cells and Animal Cells prokaryotic or eukaryotic?

Answer 1

Eukaryotic

Question 2

Are Bacterial Cells prokaryotic or eukaryotic?

Answer 2

Prokaryotic

Question 3

Which cells are smallest out of Plant cells, Animal cells, and Bacteria cells?

Answer 3

Bacteria cells.

Question 4

What is plasmid? What kind of cells is it found in?

Answer 4

Plasmid are rings of DNA. They are found in bacteria cells.

Question 5

Give the functions of the following
cell parts:
a) Ribosomes
b) Mitochondria
c) Cell membrane
d) Nucleus

Answer 5

a) Ribosomes: Protein synthesis
b) Mitochondria: Where
respiration happens
c) Cell membrane: Controls what
goes in and out of the cell
d) Nucleus: Controls cells activity
(where DNA is kept)

Question 6

Q. Give the functions of the
following cell parts:
a) Cell wall
b) Vacuole
c) Chloroplasts
d) Cytoplasm

Answer 6

a) Cell wall: Strengthens the cell
b) Vacuole: Contains cell sap
(water, salts and sugars)
c) Chloroplasts: Where
photosynthesis happens
d) Cytoplasm: Where chemical
reactions occur

Question 7

What is the main molecule that makes up cell walls?

Answer 7

Cellulose

Question 8

Name 3 cell parts that are found in Plant cells but not in Animal cells.

Answer 8

a) Cell Wall
b) Chloroplasts
c) Vacuole

Question 9

What is differentiation

Answer 9

The process where a cell become specialised

Question 10

Many animal cells differentiate an any early stage. How is this different to plant cells?

Answer 10

Many types of plant cell retain the ability to differentiate throughout their life.

Question 11

In mature animals, what is the main purpose of cell division?

Answer 11

For repair and replacement of cells.

Question 12

Why is an electron microscope
better than a light microscope?

Answer 12

Better magnification, better
resolution.

Question 13

Why have electron microscopes
been useful for understanding cell
structure?

Answer 13

Cells can be seen in much finer
detail, therefore scientists now
know more about sub-cellular
structures.

Question 14

Equation for magnification?

Answer 14

Magnification = (image size) ÷ (real life size)

Question 15

Describe the stages of mitosis.

Answer 15

• Cell grows and increases
number of sub-cellular
structures (e.g. ribosomes and
mitochondria)
• DNA replicates to form two
copies of each chromosome
• One set of chromosome is
pulled to each end of the cell
and the nucleus divides
• The cytoplasm and cell
membranes divide to form two
identical cells.

Question 16

Why is cell division by mitosis important?

Answer 16

For growth and development.

Question 17

How is DNA arranged in a nucleus?

Answer 17

Within chromosomes

Question 18

What is a stem cell?

Answer 18

An undifferentiated cell capable of becoming a variety of different types of cell.

Question 19

What are the 2 main places that human stem cells are found?

Answer 19

• Embryos
• Adult bone marrow

Question 20

Why are embryonic stem cells more useful then stem cells from adult bone marrow?

Answer 20

Embryonic stem cells are capable of changing into a wider variety of cells.

Question 21

What type of stem cells are used to make blood cells and many other types of human cells?

Answer 21

Cells from bone marrow.

Question 22

Where are stem cells found in plants?

Answer 22

In the meristem tissue.

Question 23

Name 2 conditions that stem cells can be used to treat.

Answer 23

• Diabetes
• Paralysis

Question 24

Give two reasons why someone
might want to use plant stem cells
to produce clones of plants

Answer 24

• Rare species can be cloned to
protect from extinction.
• Crop plants with special
features (e.g. disease
resistance) can be cloned to
produce large numbers of
identical plants for farmers.

Question 25

By what process do substances move in and out of cells along a concentration gradient?

Answer 25

Diffusion

Question 26

What is diffusion?

Answer 26

The spreading out of particles from an area of high concentration to an area of low concentration.

Question 27

Give 2 examples of diffusion occurring in the body.

Answer 27

• Diffusion of oxygen from the lungs into the blood. • Diffusion of nutrients from the villi (in the small intestine) into the blood.

Question 28

Give 3 factors that can affect the rate of diffusion.

Answer 28

• Concentration gradient (different concentrations) • Temperature • Cell membrane

Question 29

What 2 things increase the effectiveness of an exchange surface in plants?

Answer 29

• Large surface area • Thin Membrane

Question 30

Do single-cell organisms have a fairly large or small surface area to volume ratio?

Answer 30

Large

Question 31

Explain how the alveoli are adapted for gas exchange.

Answer 31

• Large surface area • Thin membrane • Close to efficient blood supply • Moist lining • Ventilated (air moves in and out)

Question 32

Why do multicellular organisms need exchange surfaces?

Answer 32

They have a relatively small surface area to volume ratio so need exchange surfaces to increase the surface area for diffusion of substances.

Question 33

Describe how the small intestine is adapted for exchanging materials.

Answer 33

• Covered in millions of villi • Villi provide a large surface area • Villi have a single layer of surface cells • Close network of capillaries

Question 34

Describe how a plant root is adapted for exchanging materials.

Answer 34

• Root covered in millions of tiny hairs • Root hair cells have a large surface area • Root hair cells have a thin surface

Question 35

Describe how the leaf is adapted for exchanging materials.

Answer 35

• Leaves are flat to increase the surface area • Tiny holes (stomata) allows gases to diffuse in and out. • Air spaces in leaf expose more surface of the cells

Question 36

By what process does water move across cell membranes?

Answer 36

Osmosis

Question 37

What is osmosis?

Answer 37

The diffusion of water from a dilute solution (where there are more water particles) to a concentrated solution (where there are less water particles) through a partially permeable membrane.

Question 38

What is active transport?

Answer 38

The movement of substances across cell membrane from regions of lower concentration to regions of higher concentration by the use of energy.

Question 39

Where does the energy for active transport come from?

Answer 39

Respiration

Question 40

Give an example of active transport in plant roots.

Answer 40

Mineral ions move from the soil to plant root hairs through active transport.

Question 41

Describe how molecules can move by active transport in the blood.

Answer 41

Digested food molecules (e.g sugar) can move from lower concentrations in the gut to higher concentrations in the blood.