That is the cell membrane. Think of it as a gate around a city, that is how I remember it. The city is the cell, and the cell membrane is the gate that "protects" the city, and controls what can enter and exit.
Tennis ball, flowers, and some other stuff.
Answer:
Desmosomes
Explanation:
Desmosomes are cellular structures that adhere to neighboring cells. Its function is to hold the epithelial cells together, associating the intermediate filament cytoskeletons of neighboring cells, thus forming a transcellular network with high resistance to mechanical traction. It thus allows the cells to maintain their shape and the epithelial sheet to exist in a stable form. Inside cells act as anchoring sites for intermediate rope-shaped filaments, which form a structural network in the cytoplasm providing a certain rigidity. Through these junctions the intermediate filaments of the adjacent cells are indirectly connected forming a continuous network that extends throughout the tissue.
The basics would be that you'd need to find out if they could exchange genetic information. If not, they couldn't be considered part of one species. Set-up 2 artificial environments so both groups would produce pollen at the same time. Fertilise both plants with the other's pollen. Then fertilise the plants with pollen from their own group.
Count the number of offspring each plant produces.
If the plants which were fertilised by the opposite group produce offspring, they are of the same species. You can then take this further if they are of the same species by analysing if there is any difference between the number (and health) of offspring produced by the crossed progeny and by the pure progeny. You'd have to take into account that some of them would want to grow at different times, so a study of the progeny from their first sprout until death (whilst emulating the seasons in your ideal controlled environment). Their success could then be compared to that of the pure-bred individuals.
Make sure to repeat this a few times, or have a number of plants to make sure your results are accurate.
Or if you couldn't do the controlled environment thing, just keep some pollen one year and use it to fertilise the other group.
I'd also put a hypothesis in there somewhere too.
The independent variable would be the number of plants pollinated. The dependant variable would be the number of progeny (offspring) produced.
