Atlas of plant and animal histology

Choose true or false. Each right answer scores 1, and each wrong answer scores -1. Not answered questions score 0.

1) Eukaryote cells contain a nucleus.

2) The plasma membrane separates the intracellular from the extracellular environment.

3) The cytoplasm consists of organelles, cytosol, and the nucleus.

4) A typical eukaryote cell is about 10 to 50 µm in size.

5) Eukaryote cells show a wide variety of forms, from elongated to star-like shapes. Rounded forms are not actually the most common morphology.

6) No cells were visualized before the invention of the light microscope.

7) The first microscopes were invented at the beginning of the XVIIth century.

8) R. Hook, in his book Micrographia (1664), gives the name cell to the structures that we nowadays know as cells.

9) The cell theory postulate, "All organisms are made up of units called cells", was posed by Schwann and Schleiden.

10) The cell ultrastructure can be observed with compound light microscopes.

11) The sentence "Cells arise from pre-existing cells" is a postulate of the cell theory.

12) The theories about the origin of cells do not exclude that cells may have appeared on other planets.

13) Organic molecules are only synthesized by living organisms.

14) The first cells appeared 350 million years ago.

15) The organic molecules that were used during the emergence of the first cells may have had extraterrestrial origin.

16) The laws of the Darwin evolution theory —offspring have variability and individuals are selected by the environment— may have been working before the emergence of the first cells.

17) All current cells are descendants of a common ancestral one.

18) In the origin of life, the formation of the cell membrane needed the involvement of enzymes.

19) The RNA world is the only theory that explains the evolution of the prebiotic or precellular world.

20) The genetic code is a fact that supports the idea of a universal common ancestor (LUCA) for all current cells.

21) The autogenous theory explains how mitochondria and chloroplasts appeared in eukaryote cells.

22) The endosymbiosis theory posits that the ancestor of mitochondria was incorporated before the ancestor of chloroplasts.

23) All eukaryote cells having chloroplasts share the same ancestor, which incorporated the chloroplast ancestor. The same process has happened to mitochondria.

24) Mitochondria are similar to the current aerobic bacteria.c

25) Nowadays, there are associations between eukaryote and prokaryote cells that support the endosymbiosis theory.