B1

Question 1

2 types of stem cells found in animals:

Answer 1

adult stem cells , embryonic stem cells

Question 2

what are the two key features of stem cells?

Answer 2

-they can divide by mitosis to form more cells
-they can differentiate into specialised cells

Question 3

can adult stem cells divide by mitosis

Answer 3

yes

Question 4

can adult stem cells differentiate into all types of specialised cell?

Answer 4

no

Question 5

what do we call the plant tissues that are continually growing and that contain stem cells?

Answer 5

meristems

Question 6

which two parts of the plant contain meristem tissue?

Answer 6

-tips of the shoots
-tips of the roots

Question 7

do plant stem cells persist for the plants entire life?

Answer 7

yes

Question 9

3 specialised cells in humans:

Answer 9

-Muscle cells
-Sperm cells
-Nerve cells

Question 10

3 specialised plant cells:

Answer 10

-Root hair cell
-phloem cells
-Xylem cells

Question 11

What is ‘differentiation’?

Answer 11

The process by which cells become specialised

Question 12

What 2 cells are adapted to their roles by having a large surface area?

Answer 12

-Root hair cells
-Red blood cells

Question 13

Which type of stem cell can only differentiate into different types of blood cells?

Answer 13

Adult stem cells

Question 14

Give 2 drawbacks of using embryonic stem cells in stem cell therapy:

Answer 14

-Risk of rejection
-Ethical issues associated with stem cells

Question 15

What is active transport?

Answer 15

The movement of molecules across a membrane from a region of lower concentration to a region of higher concentration. This required energy from respiration

Question 16

Is active transport a passive or active process?

Answer 16

Active
-because it requires energy

Question 17

Which process provides the energy needed for active transport?

Answer 17

Respiration

Question 18

Why can’t plants absorb mineral ions by diffusion?

Answer 18

The concentration is higher in the cell than in the soil

Question 19

Which cell in the plant are adapted to absorb mineral ions?

Answer 19

-Root hair cells

Question 20

What is diffusion?

Answer 20

The net movement of particles from an area of higher concentration to an area of lower concentration

Question 21

In which states can molecules diffuse?

Answer 21

-Liquid
-Gas

Question 22

What does a partially permeable membrane mean?

Answer 22

Only some molecules can pass through the membrane

Question 23

Which molecules are able to diffuse into and out of cells?

Answer 23

-Amino acids
-Water
-Glucose

Question 24

3 factors that affect the rate of diffusion:

Answer 24

-Concentration gradient
-Temperature
-Surface area

Question 26

What is diffusion?

Answer 26

The net movement of particles from an area of higher concentration to an area of lower concentration

Question 27

What is osmosis?

Answer 27

The diffusion of water molecules

Question 28

What is the definition of osmosis?

Answer 28

The net movement of water molecules across a partially permeable membrane, from a region of higher water concentration to a region of lower water concentration.

Question 30

What determines the concentration of water?

Answer 30

The proportion of water compared to solutes

Question 31

How does osmosis link to a cell?

Answer 31

If there water outside of the cell has a higher water concentration it will diffuse through the partially permeable membrane and into the cell which has a lower water concentration.

Question 32

In living organisms, what is the partially permeable membrane usually?

Answer 32

Cell membrane

Question 33

Osmosis is the movement of which particles?

Answer 33

Water

Question 34

T or F. During osmosis, water moves against the concentration gradient?

Answer 34

False

Question 35

What does partially permeable mean?

Answer 35

Only some molecules can pass through the membrane

Question 36

Which molecules are able to diffuse into and out of cells?

Answer 36

-Water -Glucose -Amino acids

Question 37

List 3 factors that affect the rate of diffusion:

Answer 37

-Concentration gradient -Temperature -Surface area

Question 38

Will a larger surface area increase or decrease the rate of diffusion?

Answer 38

Increase

Question 39

How do you calculate the surface area of a cube?

Answer 39

Area of a single face x 6

Question 40

How do you find the volume of a cube?

Answer 40

Length x Width x Height

Question 41

What does it mean cells can do because they have a high surface area to volume ratio?

Answer 41

They can rely on diffusion across their surface to exchange everything they need

Question 42

Would diffusion be slower in humans or cells?

Answer 42

Humans

Question 43

Give one example of an exchange surface in humans and describe its function:

Answer 43

Alveoli allows oxygen snd carbon dioxide to diffuse in and out of the bloodstream

Question 44

Give one example of an exchange surface in humans and describe its function:

Answer 44

Villi allows nutrients to be absorbed from the small intestines into the bloodstream

Question 45

What is an exchange surface?

Answer 45

A part of an organism over which substances are exchanged with the environment.

Question 46

Where are the alveoli found?

Answer 46

The lungs

Question 47

Where are the villi found?

Answer 47

In the lining of the small intestines

Question 48

What do root hair cells do?

Answer 48

Absorb water and mineral ions from the soil

Question 49

3 features that most exchange surfaces have in common:

Answer 49

- large surface area so lots of molecules can diffuse across at the same time -surfaces are very thin so substances only have to diffuse a short distance -surfaces are permeable to substances are able to pass through the surface

Question 51

3 features of the alveoli that make them good exchange surfaces:

Answer 51

-There are lots of alveoli giving them a large surface area so lots of molecules can diffuse across at the same time -Surfaces are permeable so oxygen and carbon dioxide are able to diffuse across -Surfaces are very thin so substances only have to diffuse a short distance

Question 52

What adaptation in plants contributed to the efficient exchange in plants?

Answer 52

-The flattened shape of their leaves