Answer:
<u>Passive transport</u>: It does not need any energy to occur. Happens in favor of an electrochemical gradient. Simple diffusion and facilitated diffusion are kinds of passive transport.
<u>Simple diffusion</u>: molecules freely moves through the membrane.
<u>Facilitated diffusion</u>: molecules are carried through the membrane by channel proteins or carrier proteins.
<u>Active transport</u> needs energy, which can be taken from the ATP molecule (<u>Primary active transport</u>) or from a membrane electrical potential (<u>Secondary active transport</u>).
Explanation:
- <u>Diffusion</u>: This is a pathway for some <em>small polar hydrophilic molecules</em> that can<em> freely move through the membrane</em>. Membrane´s permeability <em>depends</em> on the <em>size of the molecule</em>, the bigger the molecule is, the less capacity to cross the membrane it has. Diffusion is a very slow process and to be efficient requires short distances and <em>pronounced concentration gradients</em>. An example of diffusion is <em>osmosis</em> where water is the transported molecule.
- <u>Facilitated diffusion</u>: Refers to the transport of <em>hydrophilic molecules</em> that <em>are not able to freely cross the membrane</em>. <em>Channel protein</em> and many <em>carrier proteins</em> are in charge of this <em>passive transport</em>. If uncharged molecules need to be carried this process depends on <em>concentration gradients</em> and molecules are transported from a higher concentration side to a lower concentration side. If ions need to be transported this process depends on an <em>electrochemical gradient</em>. The <em>glucose</em> is an example of a hydrophilic protein that gets into the cell by facilitated diffusion.
<em>Simple diffusion</em> and <em>facilitated diffusion</em> are <u>passive transport</u> processes because the cell <u><em>does not need any energy</em></u> to make it happen.
- <u>Active transport</u> occurs <em>against the electrochemical gradient</em>, so <u><em>it does need energy to happen</em></u>. Molecules go from a high concentration side to a lower concentration side. This process is always in charge of <em>carrier proteins</em>. In <u>primary active transport</u> the <em>energy</em> needed <em>comes from</em> the <em>ATP</em> molecule. An example of primary active transport is the <em>Na-K bomb</em>. In <u>secondary active transport</u>, the<em> energy comes from</em> the <em>membrane electric potential</em>. Examples of secondary active transport are the carriage of <em>Na, K, Mg metallic ions</em>.
There are choices for this question namely:
<span>A) B cells produce IgE antibodies
B) B cells release cytokines
C) cytotoxic T cells present the class II MHC molecule-antigen complex on their surface
D) helper T cells release cytokines
The correct answer is "helper T cells release cytokines". Cytokines are released by helper T cells when B cells attach to them via receptors. These T cells "help" these B cells to differentiate by secreting certain cytokines. When B cells differentiate, they are converted to plasma cells and able to secrete antibodies to the antigen presented to the T cells. </span>
Riparian zones can reduce the impact of water pollution is true.
The statement is true.
<h3 /><h3>What are Riparian zones?</h3>
The areas along the banks of rivers and other sources of surface water are known as riparian zones.
The floodplain and riparian buffers bordering the floodplain are included.
Riparian zones benefit streams, groundwater, and downstream land areas in numerous ways, both environmentally and recreationally.
Thus, the given statement is true.
Learn more about Riparian zones, here:
brainly.com/question/2554838
In adults, stem cells remain undifferentiated until they are needed to repair or replace other cells. Stem cells can produce cells that are identical to themselves.
