Fifteen Minutes in the Cell Trivia Quiz

Answer: Blood cells

Even at a glance, two features are quite apparent about these cells: They are not connected and they do not possess a means of locomotion. The first observation rules out muscle and nerve cells, both of which require a tight connection to do their job and the second rules out sperm which has a mobile tail (cilium) for movement. Thus, these are blood cells - the puffy balls are leukocytes (white blood cells) and the flat disks are erythrocytes (red blood cells).

Answer: A plant

These cells are divided from each other not only by a cell membrane, but also by a clearly visible, stiff, thick cell wall. Only plant cells possess this feature.

Answer: Structure 3 shows the cell is in the process of dividing.

The structure you see in number 3 is called the central plate, composed of the cell's already duplicated chromosomes lined up and ready for pair separation. All other components are normal organelles of a plant root cell, also already separating in preparation for a normal mitotic cell division.

Answer: The nucleus

What we see here is the nucleus - the control center of the cell. Like all major organelles, it has a membrane of its own filled with plasma. In this plasma, the chromatin material (chromosomes in their unwound state) is floating. The dark spot in the middle of the nucleus is the nucleolus ("little core") where a particular type of RNA that controls cell activity is made. Cells usually only have one nucleus although there are some exceptions, such as in skeletal muscle cells.

Answer: The endoplasmic reticulum

In most animal cells, the endoplasmic reticulum attaches directly to the nucleus. On its surface, there are many ribosomes attached whose job it is to synthesize proteins based on the blueprints in the messenger RNA sent from the nucleus. Once the proteins are completed, the endoplasmic reticulum assists in their correct folding and then they are transported to their final destination in the cell.

Answer: Mitochondria

Mitochondria are the power plants of the cell. They control the most critical processes of cellular respiration, the process that breaks down glucose and oxygen into carbon dioxide and water. One molecule of glucose theoretically powers up 38 molecules of ATP, the universal intracellular energy carrier, but due to leaky membranes and the need for transporting reaction products, the net yield is about 28 to 30.

This process actually converts only one third of the original energy stored in the glucose into a usable form - not very efficient, but still 15 times more efficient than fermentation.

Answer: Golgi apparatus

The Golgi apparatus is essentially a folded membrane on which the individual vesicles drift, powered towards their destination by chemical reactions along the surface. Many of the vesicles thus transported are actually small bubbles of material that detached itself from the endoplasmic reticulum or, more rarely, the Golgi apparatus itself.

They are then often reabsorbed at their destination.

Answer: A centriole

Centrioles are the guides and architects of the microtubule structure that ultimately makes up the cytoskeleton of a cell. Besides giving the cell a more consistent shape, these structures are involved in cell division and transport. If a cell has a flagellum (a "tail" used for moving) or other means of locomotion, the centrioles and microtubuli control its action as well.

Answer: HIV viruses are infecting a blood cell.

This is definitely something that you do not want to happen in your own body: What we see here are four HIV particles of which two have just started the infection process by docking to receptors on the cell surface. The cell will then actually engulf the virus and start dissolving it, releasing its genetic material to the cell plasma. From there, it can then undermine the cell's own molecular program and use the cell's resources to multiply.

Answer: Pair C shows chromosome 22.

Pair B are unequal, marking them as an X and a Y chromosome, thus identifying a male. Pairs A and C are normal autosomes (standard paired chromosomes equal in both genders), but the numbering convention places the largest chromosomes first. Thus, C, clearly very large, cannot have a high number (in fact it is chromosome 2). Finally, we can neither prove nor disprove the genetic health of the individual.

There is nothing visibly wrong with these three pairs, but one of the other twenty could be defective or there could be a small, invisible but still fatal mutation present.