Answer:
en los jugos pancreáticos hay bicarbonato de sodio que neutraliza la alta acidez.
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.
Answer:
d.They are still very common ,but threatened with increasing harvesting for timber.
Explanation:
Brazil's Araucaria trees:
These trees are very soft and can be cut so easily.Brazilian pines is also know as Araucaria tree.
Before 1950's or 60's the number of trees were more but now due to harvesting the number of trees become less.The these trees are used for timber and for glue also.
In the present time the availability of these trees threatened with increasing harvesting for timber.
So the our option d is correct.
