The correct answer is option (d) They allow the exchange of gases between cells in the leaf and the external environment.
Stomata are the tiny openings present in the epidermis (outer layer of cells) of the leaf. They have a pore which is guarded by the guard cells which controls the opening and closing of the stomata. Air enters and exits through the stomata.
The main funtion of stomata is to facilitate the gaseous exchange. The gas exchange that occurs when the stomata are open helps in the process of photosynthesis. During photosynthesis, carbon dioxide is taken in from the atmosphere and oxygen is released as a by-product of photosynthesis. The glucose produced is converted into the starch and stored in the leaves.
Also, water vapour diffuses through the stomata into the atmosphere by a process called the transpiration.
Thus, stomata are the structures that are mainly involved in the gaseous exchange between the cells of the leaf and the atmosphere.
After the macrophage fails the Helper T Cell stimulates the B cells if pathogen is extracellular and Cytotoxic T Cells if the pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
Answer:A and D
Explanation: Because that’s what US Test Prep said was right.
Answer:
a. No discrepancy is present; organisms that contain an outer membrane and periplasmic space should stain pink because of their cell wall composition.
Explanation:
Gram stain is the staining method used to differentiate bacterial species into two groups, gram-positive and gram-negative bacteria. Factors that will differentiate gram-positive from gram-negative include the coloration of bacteria, the composition and chemical and physical properties of cell walls. In these tests, bacteria that have an outer membrane and a periplasmic space are considered gram negative and pink in color (sometimes similar to red) due to their cellular composition. For this reason we can state that there is no discrepancy present in the bacteria exposed in the question; Because this bacterium has an outer membrane and a periplasmic space, then it is normal for the bacteria to turn pink due to its cell wall composition.
Explanation:
<em><u>Option</u></em><em><u> </u></em><em><u>C</u></em> <em>is </em><em>correct</em>
<em>Hope</em><em> this</em><em> </em><em>helps</em><em> you</em>
<em>have</em><em> a</em><em> </em><em>nice</em><em> day</em>
