(Q).
Q: A biofilm is a colony of what that is stuck to a surface such as a rock or a host's tissues? Read this paragraph and choose the correct option from the provided answers: Many prokaryotes have an extra layer, called a capsule, outside the cell wall. The capsule protects the cell from chemicals and drying out. It also allows the cell to stick to surfaces and to other cells. Because of this, many prokaryotes can form biofilms, like the one shown in Figure below . A biofilm is a colony of prokaryotes that is stuck to a surface such as a rock or a host's tissues. The sticky plaque that collects on your teeth between brushings is a biofilm. It consists of millions of bacteria. Choices: - insects - eukaryotes - vacuoles - prokaryotes A:
(A).
prokaryotes

(Q).
Q: Dna consists of how many long chains of nucleotides? Read this paragraph and choose the correct option from the provided answers: DNA consists of two long chains of nucleotides. Nitrogen bases on the two chains form hydrogen bonds with each other. Adenine always bonds with thymine, and guanine always bonds with cytosine. These bonds hold the two chains together and give DNA is characteristic double helix, or spiral, shape. You can see the shape of the DNA molecule in Figure below . Sugars and phosphate groups form the "backbone" of each chain of DNA. The bonded bases are called base pairs. RNA, in contrast to DNA, consists of just one chain of nucleotides. Determining the structure of DNA was a big scientific breakthrough. You can read the interesting story of its discovery at the URL below. Choices: - three - zero - one - two A:
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two

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Q: What are vesicles made of? Read this paragraph and choose the correct option from the provided answers: A vesicle. Because vesicles are made of phospholipids, they can break off of and fuse with other membraneous material. This allows them to serve as small transport containers, moving substances around the cell and to the cell membrane. Choices: - cells - membranes - filaments - phospholipids A:
(A).
phospholipids