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All the answers above are A1. So instead, I'll give you the bigger picture. 

Photosynthesis means to "produce" (synthesis) from "light" (photo). This string of words is not very accurate at first. Let's put this into perspective:

As humans, we respire - This means we react our food (glucose) with the oxygen we inhale. This reaction is exothermic; less energy is used in starting the reaction than is released into the environment. The energy released is transferred into heat to keep us warm, and to drive other energy intensive purposes (cell division, active transport in nerve cells etc.).

Respiration: Chemical potential energy converted into other forms of energy (heat, kinetic etc.)

Respiration takes place in the mitochondria (an organelle). Carbon dioxide and water are the chemical products of this reaction. 

Plants also respire for similar purposes - that is, to keep warm and carry out energy intensive reactions. 

However, unlike humans, plants do not physically eat foods containing carbohydrates and such. How do they then acquire a store of chemical potential energy to allow respiration?

The answer is photosynthesis.  

In the chloroplast (another organelle specific to plants), energy from sunlight is used to drive the endothermic (more energy consumed than released) reaction whereby carbon from atmospheric carbon dioxide undergoes a reaction with water from the transpiration stream (water sucked up the roots, stems, into the leaf). This reaction produces glucose. Glucose is used as the chemical potential energy source for plant respiration. 

Photosynthesis: Infrared radiation / Light energy (photons) from the sun converted into chemical potential energy. 

-------------------------------------------------------------

Photosynthesis: 6H2O + 6CO2 -> 6O2 + C6H12O6 (Glucose
[IR/SUNLIGHT -> CHEMICAL POTENTIAL]

Respiration: 6O2 + 6C6H12O6 (Glucose) -> 6H2O + 6CO2
[CHEMICAL POTENTIAL -> OTHER FORMS]


Biology

What is photosynthesis?

Asexual reproduction happens via mitosis.

Why? Asexual reproduction implies that the organism does not combine its genetic material with that of another organism - It is a (“without”) - sexual (“fusion of gametes”).

This means that for it to have offspring, it simply has to clone its own cells, much like in tissue repair.

There is no need for genetic variability in offspring because we want to make clones, so no need for “crossing-over” or “independent assortment” as facilitated in meiosis with extra divisions. 

Furthermore, because we aren’t trying to create gametes (haploid), we can simply duplicate the DNA (Interphase), ready the cell for division (metaphase, anaphase, telophase) and divide the cell (cytokinesis). This produces diploid clones of the original parent cells: 

Mitosis: 46 (1 cell, diploid)-> 92 (1 cell) -> 46 x2 (2 cells, both diploid) 

As observed above, the basic steps of cell division observed in mitosis are sufficient.

That’s all! 

*** Ps. Here is what happens in meiosis:

46 (1 cell, diploid) -> 92 (1 cell) -> 46 x2 (2 cells, both diploid) -> 23 x4 (4 cells (gametes), all haploid) ***

Do the cells in an asexual reproduction divide by mitosis or meiosi

During embryonic development of the heart, there is a hole in between the atria known as the foramen ovale.

Why? Because during early development, the lungs aren’t fully developed - instead the fetus receives oxygenated blood from the placenta via the right atrium. This oxygenated blood needs to bypass the pulmonary circulation which is not ready to work yet. A hole between the atria (foramen ovale) allows this. 

As the lungs become developed, the foramen ovale shuts. The fetus now has its own functioning pulmonary and systemic circulation and so the hole is no longer needed.

Congenital (“from birth”) defects include the inability of this hole to shut. This can be due to an array of reasons, however the consequence is the mixing of oxygenated blood in the left atrium, with deoxygenated blood from the right atrium. 

This can be fatal depending on how large a hole is still present and therefore how much blood is mixed. The resulting conditions are known as Patent Foramen Ovale and Atrial Septal Defect. 

Is there ever a hole or passageway between the two atria of the heart? Why or why not?

From an evolutionary standpoint, it would be advantageous for us to process the toxins in our food before we let them enter our systemic (full body) circulation. 

The hepatic portal system is a system whereby the venous blood of the gastrointestinal tract is mixed with the arterial supply (hepatic artery) entering the liver.

This portal system blood is both relatively oxygenated and contains the sugars and toxins (from drugs e.g. alcohol) that we absorb into the blood when we eat. This system enables us to process these substrates in the liver before returning them to the heart for recirculation around the body. 

The liver is responsible for degrading toxic components of harmful drugs to reduce their alkalinity or acidity. The liver also locks away excess glucose in the form of glucagon in hepatocytes as part of the insulin response.

Tl;dr:  Venous blood from intestines joins arterial supply of liver. Liver processes these blood supplies together and produces one big venous return (hepatic vein).

What is the hepatic portal system?

Dynamic equilibriums occur for reversible reactions. 

They happen when sufficient product is formed that the rate of the reverse reaction becomes as great as the rate of the forward reaction. The result is zero net change in product and reactant concentrations. 

In a dynamic equilibrium:
1. The rate of forward reaction = Rate of backward reaction
2. The concentration of products and reactants remain constant
3. The reaction exists within a closed system (No reactant enters, no product leaves)

This is routinely asked in A level chemistry examinations. 

That’s all! 

Chemistry

What is a dynamic equilibrium?

Appreciate that blood is just like any other bodily fluid - An accumulation of water, protein and fats. 

You most likely fear it only because you picture blood in the context of life threatening or infectious situations, both of which can bring unease. Try to understand where your feelings of unease may come from. 

If you can get work as a healthcare assistant, you can begin taking blood on a regular basis. Or if you work in the hospital you can see bags of IV fluid. Expose yourself as best as you can. 

Perhaps if your family is to cook lamb next time at home, wash the meat yourself and familiarise how normal and harmless blood really is! 

General

Any tips how to get over being squeamish/ fainting of blood

The equation of the circle is: (x-a)^2 + (y-b)^2 = r^2
The equation of the tangent (linear ofc) is: y=mx+c

At the point of contact for these lines, these functions will share the same co-ordinate x & y values. 

Therefore, you can substitute the value of the tangent (mx+c) into the value of y in the circle equation. This gives:

(x-a)^2 + ((mx+c)-b)^2 = r^2

If you simplify the above, you can find 2 values for x. You can plug both values of x into the equation for the tangent to produce two y values. 

You now have 2 pairs of (x,y) co-ordinates. 

From a graphical sketch of the circle and the tangent, you can deduce which of the two co-ordinates is valid.

Maths

How do I find the point of contact of a tangent to a curve or circle

I’ll keep it short.

1. You need to satisfy your vitamin, mineral and fat requirements. Without these components, your body can not function adequately (Many enzymes derive essential components in dietary vitamins and minerals. Fat is essential to make lipid based hormones). A disease caused by the lack of something is known as a “deficiency” disease.

2. What you eat can determine your mood. E.g. Consuming chocolate late at night can make you restless due to its caffeine content. This can have a profound impact on your decisions throughout your day, and if compounded for several weeks or even months, you may notice a genuine reduction in quality of life. 

Finally there are the obvious risks of weight gain in for those in a caloric surplus. A diet exceedingly rich in any one macro (fat/protein/carb) is usually associated with one disease or another.

What do we learn? Moderation is key. 

Why is eating a healthy, balanced diet so important to the body?

Michaelis-Menten Expression (MME):

V0= Vmax*[S] / (Km + [S])
———————————————————

We know regardless of [S], Km= 1x10^-4 for this enzyme.

Observation A ([S] = 0.2M), MME:

4.3x10^4 = 0.2*Vmax_a / (1x10^-4 + 0.2)

Observation B ([S] = 0.02M), MME:

4.3x10^4 = 0.02*Vmax_b / (1x10^-4 + 0.02)

———————————————————

Therefore:

0.2*Vmax_a / (1x10^-4 + 0.2) = 0.02*Vmax_b / (1x10^-4 + 0.02)

If you simplify, you get:

Vmax_a/Vmax_b = 0.2001/0.201 = 1.00 (3.s.f)

Therefore the Vmax is almost identical in both circumstances. 

———————————————————

Both circumstances use the same Vmax and Km values to achieve the same V0 therefore the observation is feasible and accurate. 

We can derive from this that substrate concentrations at, and over, [S]=0.02M do not result in an increase in V0; the Vmax has been reached. 

The Km of a Michaelis Menten enzyme for a substrate is 1*10^-4M. At substrate conc. of 0.2M vo=43uM/min for a certain enzyme concentration. However with a substrate conc. of 0.02, vo has the same value. Show that this observation is accurate.

1. Carpals
2. Clavicle
3. Cranium
4. Femur
5. Fibula.
6. Humerus
7. Mandible
8. Metacarpals
9. Metatarsal
10. Patella
11. Pelvis
12. Phalanges (fingers)
13. Phalanges (toes)
14. Radius 
15. Ribs
16. Sternum
17. Tarsal
18. Tibia
19. Ulna
20. Vertebrae (Cervical/Lumbar/Thoracic/Sacral/Coccygeal) 

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