Answer:
<em><u>Osmosis and facilitated diffusion</u></em> are two forms of passive transport that are integral to cellular transport mechanisms.
Explanation:
Cells surrounded by a bilipid layer or plasma membrane are amphiphilic, with their polar, hydrophilic lipid heads facing outward, while their hydrophobic non-polar lipid tails facing each other inward.
Although lipid-soluble molecules travel quickly through the bilayer, traveling across its surface into the cell is often difficult for charged and large molecules. Thus, transport proteins, pores and gated channels, transmembrane channels, embedded within the membrane, help to preserve selective permeability.
Across plasma membranes as a form of passive transport in cells, substances move via:
- osmosis - water molecules readily pass through the membrane; the molecules move from high concentration regions to low concentration regions at will through the membrane- they move down their concentration gradient
- facilitated diffusion - channel proteins allow charged ions to move across the membrane. Sodium ions are able to pass freely through specialized sodium channel pores into some cells. These channels always remain open- the ions move down their concentration gradient.
Lots of factors play different kinds of roles on ecosystems.
Ecosystems are never constant because there are so many levels and layers of animals to each one. It's impossible for the headcount of each species to stay the same within an ecosystem when instances such as flooding, drought, poisoning, and hunting can take part.
Let's say the hawk, who is over the bunny on the pyramid, gets poisoned by water. Now, there's fewer hawks, which means there's less predators to hunt the bunnies, hence causing more bunnies and even increasing the chance of overpopulation.
The animals within ecosystems keep each other in check, but numbers are constantly going up and down as things happen. Natural disasters, pollution, and anything such as, effects the ecosystem, therefore it cannot remain constant.
Well mainly the survival of almost all living organism directly or indirectly depends upon the food made by the plants, with out this it will lead to the death of humans + animals
I’m not sure, try getting help from a friend
Snail:
• They have a shell that is adapted to protect them against predators and the elements.
• They are also adapted to hibernate, especially snails that live in areas prone to frost or freezing temperatures, during the winters. Alternatively, snails in dry, arid regions will estivate - a summer version of hibernation - when water is scare or when there are droughts.
• Snails' slime is naturally hygroscopic, meaning that, instead of releasing water, it attracts it. This helps snails stay damp throughout the day and assists in movement, reproduction and breathing.
Crabs:
• Instead of having an internal skeleton they have exoskeletons. This creates an extremely hard exterior making them more susceptible to attacks from predators.
• All crabs have eight regular legs and two specially adapted legs known as chelipeds or claws. They help them to feed and to catch prey.
• All crabs have both a set of antennae and antennules. They see through their eyes, which are located on the end of long eyestalks. The purpose of these eyestalks is to allow them a better field of vision -- they can see in front of themselves, behind themselves and to the sides -- which is an advantage when hunting or looking out for danger.
