Answer:
Thus, the minimum number of photons per second is 77.34
Explanation:
Light intensity,
= ![5\times 10^{-13} W/m^{2}](https://tex.z-dn.net/?f=5%5Ctimes%2010%5E%7B-13%7D%20W%2Fm%5E%7B2%7D)
Pupil has a diameter, d = 8.5 mm
= 8.5 x
m
Radius of the eye, r = 4.25 x
m
∴ Area of the eye, A = ![\pi .r^{2}](https://tex.z-dn.net/?f=%5Cpi%20.r%5E%7B2%7D)
= ![3.14\times \left ( 4.25\times 10^{-3} \right )^{2}](https://tex.z-dn.net/?f=3.14%5Ctimes%20%5Cleft%20%28%204.25%5Ctimes%2010%5E%7B-3%7D%20%5Cright%20%29%5E%7B2%7D)
= ![5.6\times 10^{-5} m^{2}](https://tex.z-dn.net/?f=5.6%5Ctimes%2010%5E%7B-5%7D%20m%5E%7B2%7D)
Let
be the minimum number of photons.
Therefore,
=
x A
=
x ![5.6\times 10^{-5}](https://tex.z-dn.net/?f=5.6%5Ctimes%2010%5E%7B-5%7D)
=
W
Thus the minimum number of photons is given by
![N_{min}=P_{min}/E](https://tex.z-dn.net/?f=N_%7Bmin%7D%3DP_%7Bmin%7D%2FE)
where E = ![hc/\lambda](https://tex.z-dn.net/?f=hc%2F%5Clambda)
= ![\left (6.63\times 10^{-34}\times 3\times 10^{8} \right )/548\times 10^{-9}](https://tex.z-dn.net/?f=%5Cleft%20%286.63%5Ctimes%2010%5E%7B-34%7D%5Ctimes%203%5Ctimes%2010%5E%7B8%7D%20%20%5Cright%20%29%2F548%5Ctimes%2010%5E%7B-9%7D)
= ![3.62\times 10^{-19} J](https://tex.z-dn.net/?f=3.62%5Ctimes%2010%5E%7B-19%7D%20J)
Therefore,
= ![\frac{2.8\times 10^{-17}}{3.62\times 10^{-19}}](https://tex.z-dn.net/?f=%5Cfrac%7B2.8%5Ctimes%2010%5E%7B-17%7D%7D%7B3.62%5Ctimes%2010%5E%7B-19%7D%7D)
= 77.34 photons per second
Thus, the minimum number of photons per second is 77.34
B - They both use protein channels (I think so at least) they differ because active transports use a pump to leave the cell and it uses atp (cell energy).
Answer:
The placenta is a unique vascular organ that receives blood supplies from both the maternal and the fetal systems and thus has two separate circulatory systems for blood: (1) the maternal-placental (uteroplacental) blood circulation, and (2) the fetal-placental (fetoplacental) blood circulation. The uteroplacental circulation starts with the maternal blood flow into the intervillous space through decidual spiral arteries. Exchange of oxygen and nutrients take place as the maternal blood flows around terminal villi in the intervillous space. The in-flowing maternal arterial blood pushes deoxygenated blood into the endometrial and then uterine veins back to the maternal circulation. The fetal-placental circulation allows the umbilical arteries
Explanation:
Answer:
The correct answer is - the placenta, the site of exchange of materials between the mother and the fetus.
Explanation:
In the given diagram there is a representation of a human embryo developing in the uterus. Different parts are numbered and the number three represents the site of exchange of materials between the mother and the fetus and this organ is called the placenta. It is the organ that develops between fetus and uterus during pregnancy that allows substances such as nutrients, to diffuse from the mother's blood to the fetus and connected by the umbilical cord.