Human/Plant diseases

Question 1

name 3 physical barriers and 2 chemical ones

Answer 1

p-leaves/stems-waxy cuticle -waxy cuticle provides barrier stop p entering dm or damaging em.
hard epidermis-bark
cell wall-cellulose- rigid barrier p
thorns/spikes
c-VOC
antiseptics kill bacterial/fungal pathogens
or toxic to their pests /deter them away

Question 2

Name some ways to check if a plant is infected with a disease.What could the problem be?

Answer 2

make observation-may show symptoms for a disease
yellow leaves,withered leaves
spots /lesions/green -environ… causes eg nutrient d
disease
silvery covering fungus
nutrient deficiency-+ n to soil ,lack of sunlight

analyse distribution of diseased plants -location of them-diif pathogens =spread diff ways ,patches = soil
random =airbourne

diagnostic testing -detecting antigens,DNA of pathogen

Question 3

what does the word aseptic mean?

Answer 3

sterile and prevents contamination/cross-contamination of samples

Question 4

How can scientists detect antigens on pathogens?

DNA?

Answer 4

unique molecules on surface=antigens
these a present in plant infected with that pathogen
detected in sample of plant tissue
detection of an antigen unique to a particular pathogen allows to be identified/diagnosed

present in plants tissue

Question 5

name 3 physical barriers in humans and 2 chemical ones

Answer 5

skin-barrier to pathogens ,damaged/cut-blood clots seal it keep microorganisms out
hairs/mucus in nose trap dust /particles with p
cells trachea ,bronchi produce mucus have cilia tiny-hair -like structures waft mucus up to back throat -swallowed-dont go into airway

stomach hydrochloric acid-kills most p swallowed
eyes-chemical lysozyme kills bacteria on surface of eye

Question 6

Explain how your immune system can attack pathogens

Answer 6

B-lymphocytes -white blood cells involved in specific immune response.
every p has unique molecules on surface=antigens
B-l.. come across antigen on p produce proteins=antibodies
bind to new invading p -so it can be found and destroyed by other w blood cells
antibodies specific to p wont bind to other p
antibodies produced rapidly flow all around body to find similar p.

Question 7

How do we use plants in medicines?

Answer 7

Quinine comes from bark of tree -treatment malaria

Aspirin-chemical bark/willow treed relieve pain /fever