An igneous rock can be formed from cooled magma. The igneous rock can become sedimentary if it is broken down by wind or water. The sedimentary rock can become metamorphic if it becomes buried in the earth, where pressure and heat would turn it into a metamorphic rock. The metamorphic rock can then become an igneous rock by melting underground and turning into magma, flowing out of a volcano, and cooling.
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.
Its conducted by the conjugation of two mature cells
<span>The answer to coprolites may contain fragments of undigested food, and thus provide valuable information about the feeding habits of fossil organisms is true. </span>
<h3><u>Answer;</u></h3>
It occurs over many generations.
It happens at the genetic level.
<h3><u>Explanation</u>;</h3>
- <em><u>Evolution is the process that involves change in the inherited traits of a population over generations. </u></em>
- <em><u>The traits involved are the expressions of genes that are copied and passed from the parents to the offspring during reproduction process. Mutations in these genes results to new traits and thus heritable differences among organisms.</u></em>
- <em><u>Therefore, evolution will only occur when there is change in gene frequency within a population over a given period of time. Genetic differences that are heritable are passed to the next generation.</u></em>