Hi
It is true that on the Galapagos islands Darwin observed tortoises with a dome and saddle shaped shells, you can see both in attached image.
Darwin observed that Galapagos Tortoises had the shells with different shapes depending on the Island they live, For example: The tortoises with saddle shaped shells were able to reach up to eat leaves of plants while the tortoises with dome shaped shells would not reach up and they would eat food from on ground sources. This made him think that the differences in tortoise shell is also a strong evidence that indicates that how tortoises have adapted themselves to better get their food as per the available resources and how they have evolved from same ancestral specie into two different species. This point also helped him in proposing the theory of evolution by natural selection.
Hope it helps!
Answer:
Cell membrane
Explanation:
The cell membrane is a flexible and permeable skin surrounding a cell.
Diffusion is the random movement of molecules or particles from a region of high concentration to a region of low concentration bringing a natural flow in the system. Diffusion ensures that there is a state of equilibrium in the number of molecules in the system.
Answer: i would say the independent variable is the soil and the control variable is the seed because it stays the same in all of them to better understand the experiment while the dependent variable is the fertilizer.
Explanation: i am not completely sure but maybe someone else can also answer to verify it first
ocean - Large bodies of water.
current flowing towards equator carry cold water from poles
current flowing towards away from equator carry warm water from poles
Example - Humidity
