Pacemaker Activity

question 37

Multiple Choice

Pacemaker activity

• A) refers to spontaneous depolarizations of the membrane resulting from shifts in passive ionic fluxes accompanying automatic changes in channel permeability.
• B) refers to spontaneous depolarizations of the membrane due to cyclical changes in Na⁺-K⁺ pump activity.
• C) is characteristic of single-unit smooth muscle but not found in any other muscle type.
• D) both (a) and (c) above.
• E) both (b) and (c) above.

---

Definitions:

Meiosis

A type of cell division that reduces the number of chromosomes by half, resulting in the production of gametes or spores in organisms.

Figure Panel

A segment or section within a larger visual representation, often used in scientific documentation.

Prophase I

The first stage of meiosis I during which chromosomes condense and homologous chromosomes pair up, leading to crossing-over.

Meiosis

A type of cell division that reduces the chromosome number by half, producing four haploid cells, crucial for sexual reproduction.