B1 cell bilogy

Question 1

state the equation for total magnification of a microscope

Answer 1

eyepiece lens times objective lens = magnifying power

Question 2

state the equation that links magnification, image size and actual size

Answer 2

image size = actual size times magnification

Question 3

define resolution

Answer 3

the ability to distinguish between two separate points that are very close together

Question 4

which type of microscope has a higher magnification and resolving power - light or electron?

Answer 4

electron microscope

Question 5

why does the tissue sample need to be stained before looking at it under the microscope

Answer 5

to see the structures clearly

Question 6

which objective lens should we start using

Answer 6

low power objective lens

Question 7

which focus knob should be used during low and medium power magnification

Answer 7

coarse focus knob

Question 8

which focus knob should be used during high power magnification

Answer 8

fine focus knob

Question 9

state the function of the nucleus

Answer 9

controls all activities of the cell, contains genetic information

Question 10

state the function of the cytoplasm

Answer 10

site for chemical reactions to take place

Question 11

state the function of the cell membrane

Answer 11

controls what substances go in and out of the cell

Question 12

state the function of the mitochondria

Answer 12

site of aerobic respiration, releasing energy

Question 13

state the function of the chloroplasts

Answer 13

contain chlorophyll, absorb light to do photosynthesis

Question 14

state the function of the permanent vacuole

Answer 14

contains cell sap to keep plants cells rigid, provide support

Question 15

what substances make up plants cell wall

Answer 15

cellulose

Question 16

Three differences between plant and animal cells

Answer 16

plant cells have chloroplasts permanent vacuole and cellulose cell wall.

Question 17

convert 5 mm to μm.(micrometers)

Answer 17

5000μm.

Question 18

state a key difference between prokaryotes and eukaryotes

Answer 18

prokaryotes do not have a nucleus.eukaryotes do have a nucleus

Question 19

state on organism that is prokaryotic

Answer 19

bacteria

Question 20

where does the genetic material of a prokaryotic cell exist?

Answer 20

cytoplasm

Question 21

what is the function of the flagella

Answer 21

to allow the cell to swim and move around.

Question 22

state a difference between animal cells and bacteria

Answer 22

Animal cells : no cell wall and plasmid, they have linear DNA. Bacteria : cell wall and plasmid, they have circular DNA

Question 23

state a similarity between plant cells and bacterial cells.. .

Answer 23

both have cell walls (but different material)

Question 24

explain the use of a tail in sperm cells

Answer 24

to swim and move around(to reach the egg)

Question 25

why do sperm cells have lots of mitochondria

Answer 25

to provide lots of energy for swimming

Question 26

describe the adaptations of a nerve cell

Answer 26

lots of dendrites; long axon

Question 27

what is the function of a nerve cell

Answer 27

carry electrical impulses

Question 28

how does having a long axon help neurons with their function

Answer 28

carry electrical impulses over a long distance

Question 29

describe how a muscle cell is adapted for its function

Answer 29

special proteins for contractions; many mitochondria for energy; store glycogen to release glucose for respiration

Question 30

root hair cells have lots of mitochondria to release energy.what is the energy used for

Answer 30

active transport of mineral ions into root hair cells

Question 31

how do the extensions in root cells help with their function

Answer 31

increase surface area for efficient water absorption

Question 32

how are photosynthetic cells adapted for photosynthesis

Answer 32

lots of chloroplasts with chlorophyll to absorb light

Question 33

define diffusion

Answer 33

net movement of particles from an area of high concentration to low concentration(down concentration gradient)

Question 34

state three factors that affect the rate of diffusion

Answer 34

concentration gradient, temperature, surface area

Question 35

how does concentration difference affect the rate of diffusion

Answer 35

higher concentration difference/steeper concentration gradient = faster diffusion

Question 36

explain why a higher temperature results in faster diffusion

Answer 36

more kinetic energy particles move around more

Question 37

name 2 substance that diffuses into our cells for use

Answer 37

oxygen, glucose

Question 38

name 2 substances that diffuse out of our cells to be removed

Answer 38

carbon dioxide and urea

Question 39

name 2 structure in the body that is adapted to increase diffusion rate

Answer 39

alveoli, villi

Question 40

define osmosis

Answer 40

net movement of water molecules from a high water concentration to a low water concentration through a partially permeable membrane

Question 41

define dilute

Answer 41

a solution with a high water concentration, but low solute concentration

Question 42

define concentration

Answer 42

a solution with a low water concentration but high solute concetration

Question 43

what are partially permeable membarnes

Answer 43

membranes that only allow some types of substances to pass through

Question 44

why does the potato skin need to be removed before putting the potato cylinders into the solutions

Answer 44

skin is impermeables

Question 45

how do we calculate percentage change in mass

Answer 45

final mass- initial mass/initial mass × 100

Question 46

define active transport

Answer 46

The net movement of particles from an area of low concentration to an area of higher concentration using energy.

Question 47

explain the importance of active transport in plants

Answer 47

root hair cells carry out active transport to absorb mineral ions effectively in dilute soil

Question 48

explain the importance of active transport in animals

Answer 48

cell in gut lining do active transport to absorb effectively from the bloodstream

Question 49

state one adaptation cells may have if they need to carry out active transport

Answer 49

lots of mitochondria for respiration for energy

Question 50

how does active transport differ from diffusion and osmosis

Answer 50

active transport uses energy however diffusion and osmosis do not

Question 51

state 2 differences between diffusion and osmosis

Answer 51

Diffusion:Any particles diffuse and it does not need a membrane. Osmosis: water is the only substance that does osmosis and it needs a partially permeable membrane

Question 52

state the relationship between size and surface area to volume ratio

Answer 52

the bigger the size the smaller the surface area to volume ratio

Question 53

describe 3 adaptations of exchange surfaces

Answer 53

large surface area ,thin membrane/surface, and ability to maintain high concentration difference

Question 54

how are alveoli adapted for efficient gaseous exchange?

Answer 54

large surface area, thin membrane(short diffusion distance), rich blood supply(maintain steep concentration gradient)

Question 55

how are plant roots adapted for efficient water and mineral absorption

Answer 55

large surface area(root hair), transpiration stream

Question 56

how does stomata help maintain efficient gas exchange in leaves

Answer 56

allow gases to move in and out of leaf, maintaining steep concentration gradient

Question 57

what is a gene

Answer 57

a short section of DNA that codes for a protein/controls a characteristic

Question 58

what are chromosomes

Answer 58

structures in the nucleus that carry genes

Question 59

how many chromosomes are in one human body

Answer 59

46

Question 60

chromosomes are arranged in ...... pairs in a human body

Answer 60

23

Question 61

how many percent of your chromosome have you inherited from your father?

Answer 61

50%

Question 62

briefly describe the cell cycle

Answer 62

cell content (DNA) is replicated, mitosis occurs to make 2 genetically identical cells

Question 63

define mitosis

Answer 63

cell division that produces two genetically identical daughter cells

Question 64

which type of reproduction is based on only mitosis

Answer 64

asexual

Question 65

state three examples where mitosis is used in organisms

Answer 65

growth,repair and asexual reproduction

Question 66

briefly describe the first stage in the cell cycle

Answer 66

cell size increase, DNA and organelle replication

Question 67

briefly describe the second stage (mitosis) in the cell cycle

Answer 67

nucleus divides - one set of chromosomes is pulled to each end of the dividing cell

Question 68

briefly describe the third stage in the cell cycle

Answer 68

cytoplasm and cell membrane divides into 2 daughter cells

Question 69

what has to happen to the cell before mitosis to ensure we can make 2 genetically identical daughter cells

Answer 69

DNA and organelles must replicate before division

Question 70

define differentiation

Answer 70

the process where a cell becomes specialised/adapted to perform specific functions

Question 71

define stem cell

Answer 71

undifferentiated cell with the potential to become specialised

Question 72

define adult stem cells

Answer 72

stem cells that can only differentiate into a specific type of cell

Question 73

where does differentiation of stem cells occur in humans

Answer 73

bone marrow

Question 74

where does differentiation occur in plants

Answer 74

meristem/root tip/shoot tip

Question 75

define cloning

Answer 75

production of identical offspring by asexual reproduction/mitosis

Question 76

by which cell division type does cloning occur

Answer 76

mitosis

Question 77

define embryo

Answer 77

a ball of cells made from mitosis of a fertilised egg

Question 78

define embryonic stem cells

Answer 78

stem cells from an early embryo that can differentiate into all cell types

Question 79

where do you get adult stem cells in animals

Answer 79

bone marrow

Question 80

suggest 2 diseases that may be treated with stem cell treatment

Answer 80

paralysis, diabetes, blindness

Question 81

briefly describe how we can use stem cells to treat someone with type 1 diabetes

Answer 81

induce embryonic stem cells to produce healthy pancreas cells to make enough insulin

Question 82

where do you get stem cells in plants

Answer 82

meristem/root tip/shoot tip

Question 83

why is the ability to clone plants quickly a benefit

Answer 83

produce large numbers of rare plants reliably and safely to stop their extinction and for her research, agriculture advances

Question 84

state one medicinal/scientific benefit of therapeutic cloning

Answer 84

no rejection problem

Question 85

state one risk or concern people may have about using stem cells

Answer 85

unethical to use aborted embryos ;difficult and expensive project ;cancer concern ;viral infection/transmission