Exam 1: Cells: The Fundamental Units of Life

Despite the differences between eukaryotic and prokaryotic cells, prokaryotes have proteins that are distantly related to eukaryotic actin filaments and microtubules.What is likely to be the most ancient function of the cytoskeleton?

Generate an analogy to describe the cell as the simplest unit of life to somebody who has not studied biology.Be sure to incorporate the observable features of living organisms, which distinguishes them from inanimate objects.

Which of the following choices BEST describes the role of the lysosome?

Chloroplasts are complex organelles present in all photosynthesizing eukaryotes.Three different membranes create chemically different environments inside the chloroplast.Precisely where are chlorophyll molecules localized in the chloroplast?

Describe the benefits and limitations of utilizing electron microscopy to understand biological systems.

Brewer's yeast, apart from being an irreplaceable asset in the brewery and in the bakery, is an experimental organism used to study eukaryotic cells.However, it does have some limitations.Select all the processes below that CANNOT be studied in yeast.

The antibiotic streptomycin inhibits protein synthesis in bacteria.If this antibiotic is added to a culture of animal cells, protein synthesis in the cytosol continues normally.However, over time, the population of mitochondria in the cell becomes depleted.Specifically, it is observed that the protein-synthesis machinery inside the mitochondria is inhibited. A.Explain this observation based on what you know about the origins of the modern eukaryote. B.What do you expect to observe if, in a new experiment, animal cells are treated with diphtheria toxin, a compound that is known to block cytosolic protein synthesis but does not have any impact on bacterial growth?

Proteins are important architectural and catalytic components within the cell, helping to determine its chemistry, its shape, and its ability to respond to changes in the environment.Remarkably, all of the different proteins in a cell are made from the same 20 __________.By linking them in different sequences, the cell can make protein molecules with different conformations and surface chemistries, and therefore different functions.

Caenorhabditis elegans is a nematode.During its development, it produces more than 1000 cells.However, the adult worm has only 959 somatic cells.The process by which 131 cells are specifically targeted for destruction is called

The __________ __________ is made up of two concentric membranes and is continuous with the membrane of the endoplasmic reticulum.

Cells that are specialized for the secretion of proteins are likely to have which of the following features?

Mitochondria contain their own genome, are able to duplicate, and actually divide on a different time line from the rest of the cell.Nevertheless, mitochondria cannot function for long when isolated from the cell because they are

Draw and annotate a diagram that explains how living systems are autocatalytic.

For each of the following sentences, fill in the blanks with the best word or phrase selected from the list below.Not all words or phrases will be used; each word or phrase should be used only once. chloroplast cytosol nucleus chromosome endoplasmic reticulum ribosomes cytoskeleton mitochondrion Eukaryotic cells are bigger and more elaborate than prokaryotic cells.By definition, all eukaryotic cells have a __________, usually the most prominent organelle.Another organelle found in essentially all eukaryotic cells is the __________, which generates the chemical energy for the cell.In contrast, the __________ is a type of organelle found only in the cells of plants and algae, and performs photosynthesis.If we were to strip away the plasma membrane from a eukaryotic cell and remove all of its membrane-enclosed organelles, we would be left with the __________, which contains many long, fine filaments of protein that are responsible for cell shape and structure, and thereby form the cell's __________.

A.thaliana, or Arabidopsis, is a common weed.Biologists have selected it over hundreds of thousands of other flowering plant species to serve as an experimental model organism because

Employ the principles of evolution discussed in this chapter to explain how the specific features and predatory behaviors of some primitive eukaryotes may have given them a selective advantage over others 1.5 billion years ago.

What is the smallest distance two points can be separated and still resolved using light microscopy?

The mitochondrial proteins found in the inner membrane are involved in the conversion of ADP to ATP, a source of energy for the cell.This process consumes which of the following substances?

Biologists cannot possibly study all living species.Instead, they try to understand cell behavior by studying a select subset of species.Which of the following characteristics are useful in an organism chosen for use as a model in laboratory studies?