Human Body Cells: Structure, Function, and Division Flashcards

A set of practice questions and answers about cell organelles, plasma membrane structure, the endomembrane system, and the process of cell division (mitosis and meiosis).

What are the three essential components found in all living human cells?

A plasma membrane, an inner cytoplasm, and a nucleus housing genetic material.

What is the relationship between cell structure and cell function?

The structure of a cell is directly related to the function of a cell.

Which cell types are categorized as cells that connect body parts, form linings, or transport gases?

Erythrocytes, Fibroblasts, and Epithelial cells.

What are the two components that make up the cytoplasm?

Cytosol (a jelly-like medium of water with solutes) and organelles ("little organs").

Describe the chemical composition of a phospholipid in the plasma membrane.

A phospholipid has a negatively charged, polar, hydrophilic phosphate "head" and two neutral, non-polar, hydrophobic fatty acid chains forming lipid tails.

What is the role of the nucleolus located within the cell nucleus?

It is responsible for manufacturing RNA for ribosomes.

According to the lecture, how is DNA copied during replication?

The DNA is untwisted and copied using DNA polymerases, resulting in new DNA molecules with one original strand and one new strand.

What percentage of the cell membrane is formed by the lipid bilayer?

$$75\%$$

Distinguish between the functions of the Rough Endoplasmic Reticulum (RER) and the Smooth Endoplasmic Reticulum (ER).

The RER is involved in protein synthesis (dotted with ribosomes), while the Smooth ER synthesizes phospholipids and steroid hormones and stores $Ca^{2+}$.

What are the functions of the Golgi Apparatus?

It is responsible for sorting, modifying, and repackaging products from the RER into vesicles for secretion or internal use.

What is "autophagy" in the context of lysosomes?

The process where lysosome enzymes break down and digest unneeded cellular components, such as damaged organelles.

How do mitochondria produce energy for the cell?

Enzymes along the highly folded inner lipid bilayer complete cellular respiration to produce $ATP$.

What are the three types of fibrous proteins that make up the cytoskeleton?

Microtubules, microfilaments (e.g., actin), and intermediate filaments (e.g., keratin).

What is the difference between diploid and haploid cells in the context of cell division?

Diploid cells (from mitosis) contain $46$ chromosomes, while haploid cells (sperm and eggs from meiosis) contain $23$ chromosomes.

What occurs during the S (Synthesis) phase of the cell cycle?

DNA duplication.

What is the defining event of Metaphase during mitosis?

Chromosomes line up at the metaphase plate and each sister chromatid attaches to a spindle fiber.

What happens to the centromeres and sister chromatids during Anaphase?

Centromeres split in two, and sister chromatids (now called chromosomes) are pulled toward opposite poles.

Describe the events of Telophase in mitosis.

Chromosomes arrive at opposite poles and decondense, nuclear envelope material surrounds each set, and the mitotic spindle breaks down.

Which types of cells are responsible for moving organs and body parts?

Skeletal muscle cells and smooth muscle cells.