industrial pollution from factories, but to classify it would be air pollution.
The earth was created by God in 7 days by forming it and calling it good on the 7th day of creation
The most accepted theory regarding the make-up of living things is the cell theory.
It was proposed by German scientists Theodor Schwan, Mathias Schleiden and Rudolf Virchow.
It states that;
1. All living organisms are made of cells.
2. The cell is the basic unit of life.
3. Cells arise from pre-existing cells.
in addition the modern version of the cell theory states:
4. Energy flow occurs within cells
5. Heredity information (DNA) is passed from cell to cell.
6. All cells have the same basic chemical composition.
Most commonly the cell<span> changes to a more specialized </span>type<span>. </span>Differentiation occurs <span>numerous times during the development of a multi cellular organism as it changes from a simple zygote to a complex system of tissues and </span>cell types<span>.</span>
Answer:
Explanation:
In a cross-section of an adult tree trunk, the outer layer that interacts with the environment is called periderm (Layer D). The second layer that follows the periderm is the phloem (Layer C). The next layer is the cambium, which produces phloem cells and xylem cells (Layer B). The secondary xylem follows the vascular cambium (Layer A) and finally, the medulla is located in the middle of the trunk.
The secondary xylem proceeds from the vascular cambium activity. Its cells are orientated in different ways composing the vertical/axial system and the horizontal/transversal system. The secondary xylem is essential to the tree growth in high because of its resistance and the capacity to transport water long distances. Secondary xylem functions are to transport water and minerals through its vessels and tracheids, to provide support and resistance to the plant, and to store reserve substances.