3.6 conditions

1. water (speed up metabolism)
2. optimum temperatures (for enzymes)
e.g starch--amylase-->maltose
3.oxygen (seeds respire aerobically-using oxygen)

3.4 fertilization

pollen grains germinate and a tube begins to grow down the stigma and connects to the ovule
pollen grains(containing male nucleus)  move down the pollen tube into ovule
1.pollen nucleus then fertilizes the ovule
this makes a zygote
which then grows into  the embrionic plant
2.outside ovule forms the TESTA or the seed coat
3.inside ovule forms cotyleton's-->food stores for seed
4. thickening of ovary walls--> fruit

3.3 Pollination

3.3b wind


Transfer of pollen from anther to stigma carried by wind
e.g plant
Adaptations:
-light weight pollen grains
-some form of wing feature
-Anthers are well clear of any flower structure (up high, exposed)
-stigma have large surface area, kind of feather like structure to catch pollen grains-also exposed
-no need for colour or sent or nectaries--no need to attract insects 


3.3a insect
Insect attractions


pollination-->transfer of pollen from the anthers to the stigma of another plant (cross pollination)
-pollen contains the male nuclei)
Insects are required to transfer the pollen, therefore the plant needs to attract the insects.
Attractions:
-Signals to the insect:
-the coloured petals
-sent
The pay off: food
-> the nectaries (produce a sugar called FRUCTOSE)
->pollen-source of protein

structure:

Male (stamen)
-Anthers and filaments
Female (carpel)
-stigma
-avary
-style

2.22 investigating photosynthesis

evolution of oxygen from a water plant
Equipment:
-Water plant
-a container filled with water (to collect the gas)
-a test tube filled with water
-glass funnel


Place the funnel in the container (so it is fully submerged)
place the end of the test tube over the end of the funnel
--take care NOT to introduce any gasses
Lift vertically (so the tube is in the air, the funnel head is still in the water)
Put the plant under the funnel (take care to ,when in the water, shake off any gas bubbles)
as the plant photosynthesises, oxygen will bubble up through the test tube and displace the water and eventually fill the tube with oxygen
this can later be tested with a glowing splint to verify that the gas in the tube is oxygen


the production of starch


the requirements of
light, carbon dioxide and chlorophyll

2.21 mineral uptake in the roots

Minerals ions are needed for growth

Mg2+Magnesium ions
- taken into roots by active transport
-sent up through xylem to leaf
-needed so plant can synthesise (make) chlorophyll

Nitrate ions NO3-
-taken into roots by active transport
-up through xylem into leaf
-makes amino acids-->which make protein
-nitrate occasionally is used to make DNA

2.52 Xylem

Water + Mineral salts (nitrates, phosphates) --> found in Soil
water taken up by root system
Minerals dissolve into the water
Water moves up through Xylem tubes from the root


XYLEM:
Inside Vascular bundle
Tube system
Thick cell walls-no pores

2.51 Phloem transportation and structure

Glucose -------------Transformed----> Sucrose
--> Reducing sugar --> non reducing sugar

Amino Acid + Sucrose=Sap
Sap= Transported through the Phloem (a tissue)

STRUCTURE:
Phloem-Inside the vascular bundle
Like a set of straw
Phloem cell wall has pores to allow the sap to go through
Can transport both up and down

2.55 rate of transpiration

Inside the plant--> region A
Outside the plant--> Region B

Concentration gradient of H2O (between A and B)
--Big difference=high diffusion rate
--small difference=low diffusion rate

Factors causing large difference:
-Low humidity=less water in the air (B)
-High winds=water blown away      (B)
-High temp=high evaporation          (B)
-High light intensity=high rate of photosynthesis and water movement (B)

Factors causing small difference:
-High humidity
-Low wind speed=water concentrates around stomata pore
-low temp=less evaporation
-low water movement, low rate of photosynthesis

2.42 Stomata Pore

Located in the lower epidermis of the leaf
Stoma=plural form
Each pore is formed by two guard cells
[] Pore []

DAY:
guard cell ->turgid and open for gas exchange

NIGHT:
guard cell->Flaccid (lost water) and closed stops gas exchange

2.41 Adaptation of a leaf

Carbon dioxide in, and oxygen out

1. Thickness of the leaf-extremley thin so diffusion distance is very small=fast diffusion times
2.stomatal pore, formed by 2 guard cells which can open and close the pore=plant has some control over gas exchange

2.40 Net gas exchange

Increase light intensity during the day
=increased rate of Photosynthesis
=more carbon dioxide used
=oxygen production increases

NET oxygen production when there is high light intensity

At night, no photosynthesis
=Net production of oxygen

2.39 Gas exchange in relation to photosynthesis and respiration

Light (photo.synt)
Carbon dioxide+water----------------------------->glucose+oxygen
 Day time


 respiration
Glucose+oxygen--------------------->Co2+h2o
 (all the time)

2.38 Diffusion in gas exchange

diffusion: high conc---->low conc

Oxygen is diffused into the cells
Carbon dioxide is diffused out of the cell

2.20 Leaf adaptation for photosynthesis

1. Large surface area - to collect light
2. Thin - Fast diffusion
3. Palisade cells - Contain Chloroplast - near top of leaf so photosynthesis can take place faster
4.Many Chloroplast-Chlorophyll--> Light collecting pigment
5. CO2-Stomatal Pore
6. Mesophyll - Many spaces 
-which allows diffusion of CO2 
-and movement of H2O
7. Vascular Bundle (vein that comes into the leaf)
-H2O to leaf
-Sap (dissolved sugars) out of leaf

2.19 How Carbon dioxide concentration, light, intensity and temperature effect the Rate of photosynthesis

***Carbon Dioxide:
More Substrate---More collision--->more Product (glucose)

***Light Intensity:
More Light-->more conversion-->More Product
At a certain amount of Light the rate will stay constant, it will increase no more. If it is too strong it can damage the Chloroplast

***Temperature:
Increase temperature--->
increase in kinetic energy of the Enzyme and the Substrate-->
More collisions (lock and key theory)--->
Faster rate of reaction

You get a "A" graph
After about 40 degrees the rate of reaction declines this is because the enzymes are being destroyed

The lowest Rate of Photosynthesis is the limiting factor-Usually Light

2.18 chemical equation

                                   ---Light Energy---
Carbon Dioxide+Water---CHLOROPHYLL--->Glucose+Oxygen
                                   ---Enzymes---

Substrate -------------------------->Product+Waste P

                       L.E
6CO2+6H2O----CHL--->C6H12O6+6O2 
                      ENZ

2.17 Photosynthesis

Light Energy---->Chemical energy using Chlorophyll
The Chemical energy = Covalent Bonds between...
_ C-C
_ C-H
_ C-O
_ O-H

Photosynthesis needs:
C, H, O

H2O ----> transpired up the stem and into the leaf
CO2 ----> Diffused into the leaf

Occurs mainly in the palisade layer