b5.1 x

Question 1

what are plant meristems?

Answer 1

A region of unspecialised cells at the top of a plant shoot that allow it to grow

Question 2

how are plant meristems similar to embryonic stem cells?

Answer 2

can become any type of plant cell

Question 3

meristems

zone of cell division

Answer 3

where unspecialised cells replicate

Question 4

some of elongate

Answer 4

after cells have been created through cell division,then elongate-get longer

Question 5

zone of specialisation

Answer 5

after they’ve elongated,start to specialise and become the different type of plant cell required by the organism

Question 6

growth in plants mainly comes from what?

Answer 6

cells elongating in the zone of elongation

Question 7

phototropism

Answer 7

growth of plant shoots towards light

Question 8

Geotropism

Answer 8

growth of plant shoots away from the ground.

Growth of roots downwards,towards the ground

Question 9

what causes cells to elongate?

Answer 9

a plant hormone called auxin.

if the hormone is present inside the plant cell then the cell will elongate

Question 10

auxin—->

Answer 10

cell elongation

Question 11

where is auxin produced?

Answer 11

in the tip of a plant shoot

Question 12

the auxin causes the cells in the zone of elongation to what?

Answer 12

stretch and grow

Question 13

what happens if auxin is evenly distributed in the plant?

Answer 13

it will grow straight upwards,however this is not always the case

Question 14

sun is shining.

what does the sunlight do to the auxin?

Answer 14

breaks it down in the lit side of the plant (so will not elongate)

Question 15

what happens to the shaded side of the plant?

Answer 15

it still has auxin inside it therefore this side will elongate

so it will bend towards the sunlight

Question 16

what happens if the tip of a plant is removed?

Answer 16

no auxin is present as it’s created in the tip so no elongation of cells

Question 17

what happens if the tip is covered by an opaque cap?

Answer 17

light cannot reach auxin in the zone of elongation so the plant has elongated evenly

Question 18

what happens if the tip is covered by a transparent cap

Answer 18

cap is clear so light can pass through and affect distribution of auxin
so grows towards sun
(normal)

Question 19

what happens if the base of a plant is covered by opaque shield?

Answer 19

auxin is found at the top of a shoot so has no affect on it

Question 20

what happens if the tip is separated by gelatin block?

Answer 20

auxin can pass through so grows towards source of light

normal

Question 21

what happens when the tip is separated by mica block?

Answer 21

auxin distributed equally-grows upwards

Question 22

multicellular organisms are made up of what?

Answer 22

collections of cells that can be specialised to do a particular job

Question 23

what are groups of specialised cells working together called?

Answer 23

tissues

Question 24

what are a group of tissues working together called?

Answer 24

organs

Question 25

what is a zygote?

Answer 25

a fertilised egg cell

Question 26

what does the zygote divide by? to form what?

Answer 26

mitosis to form an embryo

Question 27

up to and including the 8 cell stage,all the cells are what ?

Answer 27

identical and can produce any sort of cell required

Question 28

what are embryonic stem cells?

Answer 28

identical cells that can produce any sort of cell required

Question 29

what happens to most of the embryo cells after the 8 cell stage

Answer 29

most become specialised and form different types of tissue

Question 30

what happens to SOME cells after the 8 cell stage?

Answer 30

some remain unspecialised

Question 31

what are unspecialised cells called?

Answer 31

adult stem cells

Question 32

can adult stem cells ever become specialised?

Answer 32

yes at a later stage

Question 33

if you have an adult stem cell that becomes specialised at a later stage,how would it be different to an embryonic stem cell?

Answer 33

cannot become any type of cell

Question 34

only cells within meristems can what?

Answer 34

divide repeatedly

Question 35

what is it called when something can divide repeatedly?

Answer 35

mitotically active

Question 36

are cells in the meristem specialised?

Answer 36

no-unspecialised

Question 37

under what conditions can unspecialised plant cells become specialised?

Answer 37

normal hormonal conditions

Question 38

unspecialised cells can become specialised to form what?

Answer 38

different types of tissues (xylem,phloem) within organs (flowers,leaves,stems,roots)

Question 39

type of meristem | apical

Answer 39

result in increased height and longer roots

Question 40

type of meristem | lateral

Answer 40

result in increased girth

Question 41

what is xylem made from?

Answer 41

specialised cells

Question 42

what is phloem made from?

Answer 42

specialised cells

Question 43

what does xylem do?

Answer 43

carries water and minerals up the plant

Question 44

what does xylem do? | (2)replace

Answer 44

replace water lost during transpiration and photosynthesis

Question 45

what does phloem do?

Answer 45

carries sugars and amino acids both UP and DOWN the plant

Question 46

what do plant hormones do?

Answer 46

send messages to the meristems to start to produce roots

Question 47

the presence of meristems as sources of unspecialised cells allows the production of what?

Answer 47

clones of a plant from cuttings

Question 48

clones of a parent from cuttings-what may this be done to do?

Answer 48

reproduce a plant with desirable features

Question 49

what can a cut stem from a plant develop?

Answer 49

roots

Question 50

what happens after a cut stem from a plant has developed roots?

Answer 50

grows into a complete plant which is a clone of the parent

Question 51

what can rooting be promoted by?

Answer 51

the presence of plant hormones (auxins)

Question 52

what is auxin

Answer 52

plant hormone

Question 53

the growth and development of plants is also affected by what? (+2examples)

Answer 53

the environment e.g phototropism geotropism

Question 54

what does a plants survival depend on?

Answer 54

it's ability to photosynthesise

Question 55

* because a plants survival depends on its ability to photosynthesise,what do plants need? * this is demonstrated by what?

Answer 55

strategies to detect light and to respond to changes in intensity •the way in which plants will grow towards a light source

Question 56

why do the cells furthest away from a light source grow more?

Answer 56

due to the presence of auxin which is sensitive to light

Question 57

where does auxin migrate?

Answer 57

down the shoot

Question 58

what genes are switched on in embryonic?

Answer 58

all

Question 59

what genes are switched on in adult?

Answer 59

range of the genes

Question 60

before stage 8 of the 8 cell stage what are the cells doing

Answer 60

replicating

Question 61

each cell inside your body has what?

Answer 61

exactly the same dna inside it

Question 62

strand of DNA inside an eye cell

Answer 62

all of the other genetic info are switched off (producing hair,determining height etc) eye colour only one switched on

Question 63

unspecialised cell-what dna is switched on?

Answer 63

all

Question 64

specialised cell-what dna switched on?

Answer 64

only one section on rest off