She could only observe a nucleus in a eukaryotic cell. Prokaryotic cels do not have a nucleus, but the eukaryotic cell does.
Answer:
The leaves and stems of many desert plants have a thick, waxy covering. This waxy substance does not cover the stomata, but it covers most of the leaves, keeping the plants cooler and reducing evaporative loss. Small leaves on desert plants also help reduce moisture loss during transpiration.
Explanation: I hope this help's you some!!
I believe the answer to this question is a food web.
Food Web definition: "<span>a series of organisms related by predator-prey and consumer-resource interactions; the entirety of interrelated food chains in an ecological community."
Source: </span>http://www.dictionary.com/browse/food-web
Answer:
A. pH
Explanation:
Denaturation of proteins is a protein whereby the protein molecule loses its primary structure and ultimately its physical functioning as a result of factors including pH, temperature or concentration of chemicals. Based on this definition, it is visible that denaturation of proteins can be caused by these three factors: pH, chemical and temperature.
However, in this case of PEPSIN enzyme, which is a proteinous molecule produced in the stomach of humans and functions in breaking down proteins, its denaturation occurs as it moves along the digestive tract to the intestines. This is as a result of the changes in pH in the digestive tract.
The pH of the stomach where pepsin is produced is acidic i.e. <3.0. However, as one moves towards the intestine, the pH increases, which is unfavorable or considered harsh for the pepsin enzyme. Hence, it gets denatured.
Answer: Option A) Double-stranded DNA
Explanation:
First, the presence of thymine infers that the genome is DNA.
Then, to determine whether it is single or double stranded, we check if the sum of all nitrogenous bases is equal to 100%
A + C + G + T = 100%
28% + 35% + 20% + 17% = 100%
Since all bases makes 100%, we can conclude that the genome is a double stranded DNA
