Formation of the Earth's Atmosphere. The early Earth was very different from our Earth today. The early Earth experienced frequent impacts from asteroids and meteorites and had much more frequent volcanic eruptions. There was no life on Earth for the first billion years because the atmosphere was not suitable for life.
Answer:
The sodium-potassium pump is an active transporter because it needs to move sodium and potassium ions against the concentration gradient.
Explanation:
You have to think of it as outside vs inside the cell.
Outside the cell, you have 5mM K and 150mM Na. Inside the cell, you have 100mM K and 10mM sodium. Without the transporter then the ions would go from greater concentration to lower concentration. Energy keeps the ions going from the way they would naturally happen.
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
.
Where is the image for the cells?
Exocrine glands release secretions outside of the body.
One way to remember this is:
exo = outside
endo = inside
An example of an exocrine gland is a sweat gland. They release sweat (an excretion) to the outside of your body.
I hope this helps! I'm happy to answer any other questions you might have :)
