Biology

Question 0

What is the nucleolus?

Answer 0

The nucelolus is a subsection of the nucleus in which ribosomal RNA (rRNA) is synthesized.

Question 1

What is the cytosol?

Answer 1

Cytosol suspends the organelles and allows diffusion of molecules throughout the cell.

Question 2

The endoplasmic reticulum (ER).

Answer 2

A series of interconnected membranes and is continuous with the nuclear envelope. The rough ER (RER) is studded with ribosomes, which permit translation of proteins destined for secretion. The smooth ER (SER) is used for lipid synthesis and detoxification.

Question 3

The golgi apparatus.

Answer 3

Consists of stacked membrane-bound sacs in which cellular products can be modified, packaged, and directed to specific cellular locations.

Question 4

Peroxisomes

Answer 4

Peroxisomes contain hydrogen peroxide and can break down very long chain fatty acids via B-oxidation. They also participate in phospholipid synthesis and the pentose phosphate pathway.

Question 5

Microfilaments

Answer 5

Microfilaments are composed of actin. They provide structural protection from the cell and can cause muscle contraction through interactions with myosin. They also help form the cleavage furrow during cytokinesis in mitosis.

Question 6

Microtubules

Answer 6

Microtubules are composed of tubulin. They create pathways for motor proteins like kinesin and dynein to carry vesicles. They also contribute to the structure of cilia and flagella, where they are organized into nine pairs of microtubules in a ring with two microtubules at the center (9+2 structure). Centrioles are found in centrosomes and are involved in microtubule organization in the mitotic spindle.

Question 7

Intermediate filaments

Answer 7

Intermediate filaments are involved in cell-cell adhesion or maintenance of the integrity of the cytoskeleton; they help anchor organelles. Common examples include keratin and desmin.

Question 8

Parenchyma

Answer 8

The functional parts of the organ.

Question 9

Simple epithelia

Answer 9

Have only one layer

Question 10

Stratified epithelia

Answer 10

Have many layers

Question 11

Pseudostratified epithelia

Answer 11

Appear to have multiple layers because of differences in cell heights, but actually only have one layer.

Question 12

Squamous cells

Answer 12

Flat and scale-like cells.

Question 13

Epithelial tissues

Answer 13

Epithelial tissues cover the body and line its cavities, protecting against pathogen invasion and dessication. Some epithelial cells absorb or secrete substances, or participate in sensation.