Answer:
Sometimes molecules cannot move through the cell membrane on their own. These molecules need special transport proteins to help them move across the membrane. Facilitated diffusion is the diffusion of substances with the help of transport proteins in the plasma membrane. These special proteins are called channel proteins or carrier proteins, and they are attached to the cell membrane. In fact, they go through the cell membrane, from the inside of the cell to the outside. Facilitated diffusion is used for molecules that cannot diffuse rapidly through cell membranes on their own, even when the molecules are moving from high to low concentration areas. An example is the sugar plants and animals use for energy, called glucose. Even though facilitated diffusion involves transport proteins, it is still passive transport because the solute is moving down the concentration gradient so it does not require the use of cellular energy.
Answer:
- It has a vital role. It is the only way out of the optic nerve. By this hole optic nerve exits from the eye and goes towards the brain.
- It can be proved by a simple experiment. A paper sheet is taken. Then a cross and a circle are drawn side by side on that paper. Then we will focus on the cross. Then by closing one eye and by bringing the paper slowly towards our face, the circle will be disappeared at a certain point.
Explanation:
The blind spot is a region on the retina where ganglion cells connect with the optic nerve, and the optic nerve and blood vessels leave the eyeball. There are no receptors in this area so nothing can be translated into vision. That's why the blind spot is unable to see things.
Answer:
A bottom-up system concentrates attention on how resources (space and nutrients) influence higher trophic forms , whereas a top-down system focuses on interactions at top level consumers (predators) and their prey influence on lower trophic forms.
Explanation:
hope it helps you !
Metals are malleable
Metals are ductile
Metals are good heat and electricity conductors
Metals lose electrons in reactions.
Answer:The bodies of different species are similar.
The development of different species are similar.
The DNA of different species are similar.
Experiments can form the molecules of life out of chemicals.
Fossils show a history of life that gets more complex.
Fossils show different stages of evolution in a species.
The fossil record is backed up by the geological record.
Explanation: their all true, i did the lesson
