Both genes need to be recessive in order for a recessive trait to be expressed.
I hope this helps!
DNA is going to be the answer
Answer:
Explanation:
From the information given:
The cell potential on mars E = + 100 mV
By using Goldman's equation:
![E_m = \dfrac{RT}{zF}In \Big (\dfrac{P_K[K^+]_{out}+P_{Na}[Na^+]_{out}+P_{Cl}[Cl^-]_{out} }{P_K[K^+]_{in}+P_{Na}[Na^+]_{in}+ P_{Cl}[Cl^-]_{in}} \Big )](https://tex.z-dn.net/?f=E_m%20%3D%20%5Cdfrac%7BRT%7D%7BzF%7DIn%20%5CBig%20%28%5Cdfrac%7BP_K%5BK%5E%2B%5D_%7Bout%7D%2BP_%7BNa%7D%5BNa%5E%2B%5D_%7Bout%7D%2BP_%7BCl%7D%5BCl%5E-%5D_%7Bout%7D%20%7D%7BP_K%5BK%5E%2B%5D_%7Bin%7D%2BP_%7BNa%7D%5BNa%5E%2B%5D_%7Bin%7D%2B%20P_%7BCl%7D%5BCl%5E-%5D_%7Bin%7D%7D%20%20%20%20%20%20%5CBig%20%29)
Let's take a look at the impermeable cell with respect to two species;
and the two species be Na⁺ and Cl⁻
![E_m = \dfrac{RT}{zF} In \dfrac{[K^+]_{out}}{[K^+]_{in}}](https://tex.z-dn.net/?f=E_m%20%3D%20%5Cdfrac%7BRT%7D%7BzF%7D%20In%20%5Cdfrac%7B%5BK%5E%2B%5D_%7Bout%7D%7D%7B%5BK%5E%2B%5D_%7Bin%7D%7D)
where;
z = ionic charge on the species = + 1
F = faraday constant
∴
![100 \times 10^{-3} = \Big (\dfrac{8.314 \times 298}{1\times 96485} \Big) \mathtt{In} \Big ( \dfrac{4}{[K^+]_{in}} \Big)](https://tex.z-dn.net/?f=100%20%5Ctimes%2010%5E%7B-3%7D%20%3D%20%5CBig%20%28%5Cdfrac%7B8.314%20%5Ctimes%20298%7D%7B1%5Ctimes%2096485%7D%20%5CBig%29%20%5Cmathtt%7BIn%7D%20%20%5CBig%20%28%20%5Cdfrac%7B4%7D%7B%5BK%5E%2B%5D_%7Bin%7D%7D%20%20%20%5CBig%29)
![100 \times 10^{-3} = 0.0257 \Big ( \dfrac{4}{[K^+]_{in}} \Big)](https://tex.z-dn.net/?f=100%20%5Ctimes%2010%5E%7B-3%7D%20%3D%200.0257%20%5CBig%20%28%20%5Cdfrac%7B4%7D%7B%5BK%5E%2B%5D_%7Bin%7D%7D%20%20%20%5CBig%29)
![3.981= \mathtt{In} \Big ( \dfrac{4}{[K^+]_{in}} \Big)](https://tex.z-dn.net/?f=3.981%3D%20%5Cmathtt%7BIn%7D%20%5CBig%20%28%20%5Cdfrac%7B4%7D%7B%5BK%5E%2B%5D_%7Bin%7D%7D%20%20%20%5CBig%29)
![exp ( 3.981) = \dfrac{4}{[K^+]_{in}} \\ \\ 53.57 = \dfrac{4}{[K^+]_{in}}](https://tex.z-dn.net/?f=exp%20%28%203.981%29%20%3D%20%5Cdfrac%7B4%7D%7B%5BK%5E%2B%5D_%7Bin%7D%7D%20%5C%5C%20%5C%5C%20%2053.57%20%3D%20%5Cdfrac%7B4%7D%7B%5BK%5E%2B%5D_%7Bin%7D%7D)
![[K^+]_{in} = \dfrac{4}{53.57}](https://tex.z-dn.net/?f=%5BK%5E%2B%5D_%7Bin%7D%20%3D%20%5Cdfrac%7B4%7D%7B53.57%7D)
![[K^+]_{in} = 0.0476](https://tex.z-dn.net/?f=%5BK%5E%2B%5D_%7Bin%7D%20%20%3D%200.0476)
For [Cl⁻]:
![100 \times 10^{-3} = -0.0257 \ \mathtt{In} \Big ( \dfrac{120}{[Cl^-]_{in}} \Big)](https://tex.z-dn.net/?f=100%20%5Ctimes%2010%5E%7B-3%7D%20%3D%20-0.0257%20%5C%20%20%5Cmathtt%7BIn%7D%20%5CBig%20%28%20%5Cdfrac%7B120%7D%7B%5BCl%5E-%5D_%7Bin%7D%7D%20%20%20%5CBig%29)
![-3.981 = \ \mathtt{In} \Big ( \dfrac{120}{[Cl^-]_{in}} \Big)](https://tex.z-dn.net/?f=-3.981%20%3D%20%20%5C%20%20%5Cmathtt%7BIn%7D%20%5CBig%20%28%20%5Cdfrac%7B120%7D%7B%5BCl%5E-%5D_%7Bin%7D%7D%20%20%20%5CBig%29)
![0.01867 = \dfrac{120}{[Cl^-]_{in}}](https://tex.z-dn.net/?f=0.01867%20%3D%20%20%5Cdfrac%7B120%7D%7B%5BCl%5E-%5D_%7Bin%7D%7D)
![[Cl^-]_{in} = \dfrac{120}{0.01867}](https://tex.z-dn.net/?f=%5BCl%5E-%5D_%7Bin%7D%20%3D%20%5Cdfrac%7B120%7D%7B0.01867%7D)
![[Cl^-]_{in} =6427.4](https://tex.z-dn.net/?f=%5BCl%5E-%5D_%7Bin%7D%20%3D6427.4)
For [Na⁺]:
![100 \times 10^{-3} = 0.0257 \Big ( \dfrac{145}{[Na^+]_{in}} \Big)](https://tex.z-dn.net/?f=100%20%5Ctimes%2010%5E%7B-3%7D%20%3D%200.0257%20%5CBig%20%28%20%5Cdfrac%7B145%7D%7B%5BNa%5E%2B%5D_%7Bin%7D%7D%20%20%20%5CBig%29)
![53.57= \Big ( \dfrac{145}{[Na^+]_{in}} \Big)](https://tex.z-dn.net/?f=53.57%3D%20%5CBig%20%28%20%5Cdfrac%7B145%7D%7B%5BNa%5E%2B%5D_%7Bin%7D%7D%20%20%20%5CBig%29)
![[Na^+]_{in}= 2.70](https://tex.z-dn.net/?f=%5BNa%5E%2B%5D_%7Bin%7D%3D%202.70)
Option D – amphibians may use their skin for gas exchange is the characteristic feature of amphibians that differs from reptiles.
Explanation:
The amphibian skin is moist, thin and marbled and supplied by blood vessels running on its surface. The moisture present in the skin dissolves the oxygen present in its surrounding which is absorbed by the blood vessels. Special glands help the amphibians to keep the skin moist.
The very thick and tough scales present on the reptiles prevent them to absorb oxygen through their skin. Hence, they breathe and respire through their lungs.
Amphibians have three-chambered heart. They do not develop amniotic eggs. Adult amphibians although spend much time on land, they breed only in water due to the absence of amniotic sac
.
Human chorionic gonadotropin (hCG) is secrete by the embryo early in pregnancy to keep the corpus luteum for dying. This positive feedback will maintain the corpus luteum, which secretes Progesterone and Estrogens throughout pregnancy, in order to keep the endometrium well to nourish the embryo/fetus.