The answer is ( In the early stages the embryos of four different species will look the same .For example, fish embryos and human embryos both have gill slits. In fish they develop into gills, but in humans they disappear before birth. That what makes them different.)
Im pretty sure that it is the letter ::::A ..
hope this helped xoxo
A Protein Pump :- Protein pumps use energy from hydrolysis of ATP to move ions or large molecules across cell membrane.
Purpose of a Protein Pump :- In a Protein Pump the proteins help in active transport of molecules. Example, Membrane proteins are very specific and help in active transport. These proteins are positioned to cross the membrane so one part on the inside of the cell and one part is on the outside of the cell. Only when they cross the bilayer(cell membrane) they are able to move molecules and ions in and out of the cell.
Need for a Protein pump to work :- In active transport, A protein pump changes its shape when allows movement of molecules and therefore requires energy in the form of ATP. They use the energy of ATP hydrolysis to move ions or small molecules across a membrane.
Answer:
Climate change, shortage of natural resources, waste in the environment, decreasing biological diversity, toxic chemicals, water pollution, shortage of water resources and air pollution.
hope this helped!
"The first step in DNA replication is to 'unzip' the double-helix structure of the DNA <span>molecule."</span>