CPG 8 Flashcards
What is a communicable disease?
Communicable disease can be spread from one organism or person to another.
communicable vs contagious
communicable is direct contact or indirect (water etc.) whereas contagious is from droplets or proximity.
E.g. malaria is communicable but not contagious
What is a risk factor for a disease?
Something that increases the likelihood of contracting a disease
What are FOUR different risk factor categories
- Smoking
- Poor diet
- Genetics - predisposition to (breast cancer e.g.)
- High alcohol consumption
What is an environmental risk factor for disease? THREE
- Pollution
- Toxins in water
- Radiation/UV
Where would you find meristem tissue in a plant? TWO
Tips of the roots
Tips of the stems
What does Xylem carry
water & minerals
Why is meristem useful for plants
Can differentiate into any type of plant cells
What cells are the main place where photosynthesis takes place
Palisade cells
How are palisade cells adapted for photosynthesis. TWO
- Lots of chloroplasts, which contain chlorophyll, the pigment used for capturing sunlight
- Column-shaped and tightly packed: more surface area for light absorption and allows chloroplasts to be exposed to light.
Difference between translocation and transpiration?
Transpiration = Xylem = Water - moves in one direction from root to leaves
Translocation = Phloem = Food (sugars) - moves up and down the stem
Explain transport of water and minerals as well as sugars via phloem and xylem.
Xylem - made up dead cells that are end to end - walls strengthened with lignin.
Water and minerals go from roots to the stem and leaves. Transpiration.
Phloem - living cells with pores - so cell sap can flow through. So dissolved sugars made in the leaves can travel to the rest of the plant - goes in both directions. Translocation.
Function of guard cells
- Allow gas exchange
- Control water loss - close when water is scarce.
what type of drug can be used to control HIV
ARVs (Antiretroviral)
How does TMV affect a plant’s growth
Damages choloplasts which are needed for photosynthesis.
One species of plant vulnerable to TMV
tomato plant
Rose black spot - what does it look like? What effect does it have on plant.
Leaves have dark purple or black spots with a yellow margin. Leaf tissue is damaged, can’t photosynthesise.
How does rose black spot spread to other plants
fungal spores carried by wind or rain.
