Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Subject - Biology - Cell Struction (Chapter 4: Biology Concepts and Applications

ID: 274655 • Letter: S

Question

Subject - Biology - Cell Struction (Chapter 4: Biology Concepts and Applications, Starr (10th Edition)

Discuss the cell theory. What are the four tenets (or principles) of the cell theory?

Is a virus alive?

Define cytoplasm vs cytosol

What are organelles? Provide some examples

Do all cells have a plasma membrane? Is this always the most exterior portion of a cell?

Do all cells have a cell wall? Is this always the most exterior portion of a cell?

Discuss the nucleus of a cell

Discuss the fluid mosaic model

Explain the phospholipid bilayer. Which areas of phospholipids are hydrophobic? Which areas of phospholipids are hydrophilic? How does this keep water inside the cell, and outside the cell?

Discuss cell surface receptor proteins

Describe the structural features found in prokaryotes (which organelles are present, which are not)

Be able to label parts of a generalized bacterium (Figure 4.9)

Explanation / Answer

Solutions

1. The cell theory states that the cell is the basic structural and functional unit of life. It means that, no biological moiety can exist independently if it is lower than the cell in hierarchy. The tenets of cell theory are –

All living organisms are comprised of cells.

An organism can be unicellular or multicellular.

Cells arise fromcells

Cells form the structural and functional backbone of the organism.

2. Viruses cannot be classified as completely living or non-living. They are complex biological molecules comprising of proteins, nucleic acids, lipids, and carbohydrates. However, they cannot replicate on their own. They require a host cell, whose replication machinery they can hijack, and use it to replicate its own genetic content.

3. The part of the cell within the cell membrane is called as the cytoplasm. It can be considered as the total content within the cell membrane, not considering contents of the nucleus of the cell. Cytosol is the part of the cytoplasm which is not contained by any of the organelles in the cell.

4. In the eukaryotic cell, organelle is defined as one of several specialized structures with specialized functions, which are in a suspended form in the cytoplasm. Some of the examples are mitochondria, chloroplast, golgi bodies, endoplasmic reticulum, etc.