Plant diseases and defences

Question 1

What happens if plants don’t get enough mineral ions

Answer 1

They suffer deficiency symptoms, like stunted growth

Question 2

What are nitrates needed for in plants

Answer 2

To make proteins which are used for growth

Question 3

What ions are needed for making chlorophyll

Answer 3

Magnesium ions

Question 4

What are magnesium ions used for in plants

Answer 4

Making chlorophyll which is needed for photosynthesis

Question 5

What do plants who don’t have enough magnesium ions suffer from

Answer 5

Chlorosis and yellow leaves

Question 6

Signs that a plant has a disease

-s… g…
-a… g… eg …
-s…
-m… s… or l…
-p… of d…
-d…

Answer 6

-stunted growth
-abnormal growth eg lumps
-spots
-malformed stems or leaves
-patches of decay
-discolouration

Question 7

How can plant diseases be identified

-using a g… m…
-taking the i… plant to a …, where scientists can i… the …
-using … kits using … antibodies

Answer 7

-using a gardening manual
-taking the infected plant to a laboratory, where scientists can identify the pathogen
-using testing kits using monoclonal antibodies

Question 8

Physical, chemical and mechanical defences of plants

Physical:
-w… c…
—>b… to stop … from entering
-c… w…
—>forms a … barrier
-layers of d… cells around their …
—>eg … on trees
—>act as a …

Chemical:
-some produce a… c…
—>kill …
—>eg … plant, witch …
-some produce …
—>deter h…
—>eg … plants, fox …

Mechanical:
-t…
—>stop animals … them
-h…
—>stop … touching them
-some d… or c…
—>when in … with something
—>prevent being …
-some m… other o…
—>eg poison flower looks like … eggs
—>t… organisms into not … them

Answer 8

Physical:
-waxy cuticle
—>barrier to stop pathogens from entering
-cell wall
—>forms a physical barrier
-layers of dead cells around their stems
—>eg bark on trees
—>act as a barrier

Chemical:
-some produce antibacterial chemicals
—>kill bacteria
—>eg mint plant, witch hazel
-some produce poisons
—>deter herbivores
—>eg tobacco plants, fox gloves

Mechanical:
-thorns
—>stop animals touching them
-hairs
—>stop animals touching them
-some droop or curl
—>when in contact with something
—>prevent being eaten
-some mimic other organisms
—>eg poison flower looks like butterfly eggs
—>trick organisms into not eating them