Answer:
C. wavelengths of light and the rate of photosynthesis
Explanation:
The experiment by Theodor W. Engelman demonstrated the relationship between wavelengths of light and the rate of photosynthesis.
Various experiments have reported that the optimal regions of white light that drive photosynthesis is the red and blue regions.
During photosynthesis, carbon dioxide and water is utilized to synthesize glucose and oxygen is produced as a result. Hence, the rate of production of oxygen is directly proportional to the rate of photosynthesis.
<em>Therefore, the more the photosynthesis rate, the more the oxygen produced and the more the growth of aerobic bacteria. This is why more bacterial growth was observed around the red and blue region of white light according to Engelmann's observation.</em>
The correct option is C.
Answer:
Most plants absorb water through the roots. Land plants get almost all the water they need from the soil. The amount of water available in the soil varies according to its porosity and its degree of desiccation. A large proportion of water is retained by cohesion forces between the particles. When the water is in the roots it moves inside the plant through the xylem. The xylem is the transport system that carries water to the entire plant.
Explanation:
The xylem connects all parts of the plants (from the roots to the stems and from there to the leaves). The water in the xylem creates a gigantic chain of molecules that adhere to each other, just like they adhere to the xylem. For plants to transport water from roots to leaves and use it in other functions, other structures called stomata are required. Stomata are small pores in leaves that plants can open and close as needed. If they open, the water moves out of the stomata and evaporates into the air. This occurs because the water molecules diffuse, from the humid air inside the leaf, to the much drier air surrounding the leaf. The loss of water through the stomata together with the high cohesion of the water particles and the resistance of the root "stress" the water column. This causes the water potential of the roots to decrease and the surrounding water enters the plant.Each stoma is made up of two occlusive cells. When these cells are turgid, a hole opens between them; when the cells relax, the hole disappears. The turgor pressure depends directly on the inlet or outlet of the water. This movement, in turn, depends on the concentration of solutes within the cell.
Answer:
The correct option is A. Measuring radioactive decay of element isotopes
Explanation:
At the time of formation of rock, certain kinds of radioactive isotope elements get trapped in the rock. These radioactive isotopes are unstable and decay over a period of time forming daughter elements. A rock which will have more number of radioactive elements will be newer to a rock containing non-radioactive daughter elements.
The radioactive decay of each element can be measured by the half-life of elements. This is the primary technique to determine the absolute age of a rock.
Answer:
1/2 or 50%
Explanation:
Given that the extra digit is a dominant trait, the man with an extra digit may be homozygous or heterozygous dominant for the trait.
However, having a daughter with his normal wife makes him heterozygous dominant. Let's assume that the genotype of the heterozygous dominant male is "Dd" and that of his wife is "dd".
The heterozygous dominant male and homozygous recessive female would have progeny in the following ratio= 1/2 Dd (child with extra digit): 1/2 dd (child with no extra digit).
Answer:
in the wall of the right atrium of the heart.
Explanation:
The sinoatrial node (SA), consisting of spindle-shaped cells, initiates the electrical activity of the heart. From its location in the right atrium in proximity to the superior vena cava, the electrical activity spreads to the atria, whose cells are larger than those of the SA.