That is true. Active transport goes against the concentration gradient. Particles want to move from higher concentration to lower concentration and even out, but active transport makes them move against that.
Embryologist study embryos because Embryology is central to evolutionary developmental biology ("evo-devo"), which studies the genetic control of the development process (e.g. morphogens), its link to cell signalling, its roles in certain diseases and mutations, and its links to stem cell research.
According to the Big Bang theory, the universe was once very dense and is now expanding.
Answer
The 4 events that occur during amoeba are:-
- It sees the food particle.Then by pseudopodia (the finger like projections from amoeba) traps the food particle.
- The finger-like extensions of the cell surface fuse over the food particle forming a food vacuole.
- Inside the food vacuole, complex foods are broken down into simpler ones which then diffuse into the cytoplasm.
- The remaining undigested material is moved to the surface of the cell and thrown out. [Egestion].
