Answer:
Plants stem grow against the gravity while roots grow towards the gravity and this prices is known as the geotropism or gravitism explains that the roots grow toward the direction of the gravity pull termed as positive geotropism.
Auxin is a hormone that acts at the bottom of the cell and have different function in roots and stems as in stems it promotes the elongation of the cell against gravity while in roots it is promotes the elongation of the cell towards the gravity.
Answer:
A molecule of the kind normally found in living systems. Organic molecules are usually composed of carbon atoms in rings or long chains, to which are attached other atoms of such elements as hydrogen, oxygen, and nitrogen.
Explanation:
“cells seemed to he enveloped by a selectively permeable layer that allowed different substances to enter and leave cells at significantly different rates. He recognized that lipid-soluble substances penetrated readily into cells, whereas water-soluble substances did not. He concluded that lipids were present on the cell surface as some sort of a "coat." Irving Langmuir (1881-1957) proposed that that cells were covered by a lipid monolayer.”
Answer:
Sponges are the members of the phylum Porifera. They have cellular level of body organization and they are sedentary. The space, food and other resources are limited. This leads to lot of competition for space among the sponges. Some of the sponges produce toxins to stop other sponges from settling down nearby or very close to another one. Toxins secreted by sponges provide a competitive advantage.
