C. How long does it take a paper bag to break down?
Epidermal tissue system is the outermost covering of plants. It consists of epidermis, stomata and epidermal outgrowths. Epidermis is generally composed of single layer of parenchymatous cells compactly arranged without intercellular spaces. But it is interrupted by stomata. In leaves some specialized cells which surround the stomata are called the guard cells.
Because you might have just done something different with the experiment and messed up someway during the test
Answer:
The correct answer would be calcium ion and cAMP.
Secondary messengers refers to the intracellular signaling molecules which pass the signals from the receptors located on the surface of the cell to the target molecule present within the cell.
The secondary messengers can be classified into three major class:
- Cyclic nucleotide for example cAMP (cyclic adenosine monophosphate), cGMP (cyclic guanosine monophosphate)
- DAG (diacylglycerol) and IP₃ (inositol triphosphate)
- Calcium ions (Ca⁺⁺)
Hence, from the given options, calcium ion and cAMP would make the correct choice.
For one thing based off of process of elimination we know that both plant and animal cells have a cell membrane, and a nucleus. Therefore we are left with cytoplasm and cell wall. According to the question we are most likely looking for something in the animal or plant cell that they don’t have in common with each other. Therefore, the answer is cell wall because an animal cell doesn’t have a cell wall, but a plant cell does. The cell wall can also make it more rigid!