The lipid components of cellular membranes often include phospholipids and cholesterol. Phospholipids is made up of glycerol, fatty acids, phosphate and organic derivatives such phospho inositol and choline. Cholesterol is the component of the membrane lipid which determine the fluidity of the memebrane; it also participates in membrane singalling system.
Answer:
The four- chambered hearts of birds and mammals are best described as <u>homoplasies.</u>
Explanation:
In evolution, homoplasies are the trait shared in different species despite that their ancestors didn't have it at all. In other words, these are traits that can be gained or lost during evolution in different lineages independently. For example, wings of birds and wings of bats do the same function (help in flying) but they were not there in the ancestors so both animals developed these structures independently.
In the given example, birds and mammals have four-chambered heart but their ancestors have 3 chamber hearts. They evolved independently and developed 4 chamber heart. This might be due to several reasons. However, their ancestors didn't have the feature so it is an example of homoplasy.
Student 1’s methods would be more accurate, because the student would control more factors. Only one variable at a time (either temperature or acidity) would be tested on each group of worms. On the other hand, Student 2 is testing both factors on all the worms, which could make the results unclear.
If the fertilizer is placed around the root of a tomato plant, the leaves of the plant will shrivel and turn brown. This phenomenon in terms of tonicity is that;
- inside the root cell is hypotonic since it contain more water than surrounding .
- In the other hand the cell is hypertonic since it contain more solute from fertilizer.
- Through osmosis water move out of the cell therefore the it turns to brown.
