Answer:
sieve-tube elements, companion cells
Explanation:
Sieve-tube elements and companion cells are responsible for the movement of photosynthes through a plant.
The sieve tube elements are shorter (almost organelle-free) living cells, placed end to end, forming the sieve tubes. Their transverse cell walls are called sieve plaques that make connections between cells and through openings called sieves establish the connection between the cytoplasm of adjacent cells. Each sieve is coated with calose (glucose polymer), which in winter can completely clog the vessel and then dissolve in spring. When infections occur or the vessel is parasitized, it can also be clogged with callose.
Companion cells are specialized parenchymal cells, which contain all the components that exist in living cells, including the nucleus, are the cells most closely linked to the sieved tube element. The Screened Tube Element and its companion cells are related in development, are derived from the same mother cell, and have several cytoplasmic connections to each other. Due to the many connections, the potential function of the companion cells is to release substances into the sieved tube element and, when the nucleus is absent, to include information molecules, proteins and ATP. When a screened element dies, its companion cells also die, which is a demonstration of this interdependence.
Answer:
Using the concept of relative dating
Explanation:
Scientists use the concept of relative dating principles to determine when the Great Oxidation event occurred.
Relative dating is the process of placing ancient event in their proper time sequence based on the relationship between rock lithologies.
- An event like the great oxidation will have significant chemical, biological and physical effect on the rock units.
- Rocks that form during this period in time will have very unique chemical signatures.
- Therefore, by studying these rocks, the age of the layer can be fixed when we compare it to the standard geological column.
The children were given the recessive traits from their mother and the dominant traits from their father because the genes mix when they have children.
