The correct answer is b, antigens
Lets look at your first question. A food chain is a linear (line) relationship between organisms. It shows who eats what and who gets eaten. The energy is passed up the chain from one organisms to the next. A food web is a series of interconnected food chains. It can show one organism being preyed upon by several predators. The answer choice A is really referring to an energy pyramid, but it is true in any ecosystem that only 10% of available energy is passed to the next trophic level. B and C are both true statements as well. D is completely false because 90% of energy is lost, not retained. So with that said, there is more than one correct answer here. I have included a diagram so you can see the difference between the two.
For Question 8, the key to understanding this is that sunlight is the main source of energy for any ecosystem. Plants (autotrophs) use the sunlight to convert it to sugars (glucose) which is a compound that heterotrophs can utilize. This process is called photosynthesis. :-)
Question 9: So in a food chain, you typically start with the producers (plants), then to the primary consumer, then secondary consumer, then tertiary consumer, and in some cases you may have a quaternary consumer. That is 4 links. However, we are forgetting the role of decomposers at all levels of this food chain, and that would add an extra link. In summary, you wouldn't typically see more than 5 links in a food chain.
I hope all of my explanations are helpful! Good luck! :-)
-Water evaporates and condenses into clouds, then the clouds are blown over the ocean, and it rains.
-Water from a mountain flows down and into a river. The river empties into an ocean.
Answer:
Signal transduction pathways
Explanation:
Plant hormones act by directly affecting the activities of signal transduction pathways.
Signal transduction pathways are involved in the transfer of signals from outside of the cell to the inside of the cell for the regulation of various cellular activities. For this, the extracellular signalling molecules bind to the receptors that are located on the cell membrane. After their binding due to some change in the receptor molecule, a signal is triggered in to the cell and thus information from outside of the cell is transferred to the inside of the cell through these transduction pathways.
Plant hormones affect these pathways and as a result membranes, enzymes, and genes are also influenced by the plant hormones.