Dynein is missing from the cilia and flagella of individuals with a specific inherited disorder. These individuals have severe respiratory problems and, if males, are sterile. What is the structural connection between these two symptoms?

Verified step by step guidance

1. Step 1: Understand the role of dynein in cilia and flagella. Dynein is a motor protein responsible for the bending movement of cilia and flagella by causing microtubule sliding within their axoneme structure.
2. Step 2: Recognize that cilia line the respiratory tract and help move mucus and trapped particles out of the lungs, which is essential for respiratory health and preventing infections.
3. Step 3: Note that flagella are responsible for the motility of sperm cells, enabling them to swim towards the egg for fertilization.
4. Step 4: Connect the absence of dynein to impaired motility of both cilia and flagella, leading to ineffective mucus clearance in the respiratory tract (causing respiratory problems) and immotile sperm (causing male sterility).
5. Step 5: Conclude that the structural connection is the shared axonemal structure of cilia and flagella, which relies on dynein for movement; thus, dynein deficiency affects both respiratory cilia and sperm flagella, causing the observed symptoms.

Key Concepts

Role of Dynein in Cilia and Flagella

Dynein is a motor protein essential for the movement of cilia and flagella. It generates sliding forces between microtubules, enabling these organelles to beat and produce motion. Without dynein, cilia and flagella become immotile, impairing their biological functions.

Function of Cilia in Respiratory Health

Cilia line the respiratory tract and help clear mucus and trapped particles by coordinated beating. When cilia lack dynein and cannot move, mucus accumulates, leading to respiratory problems such as infections and impaired lung function.

Role of Flagella in Male Fertility

The flagellum of sperm cells propels them toward the egg for fertilization. Dynein-driven movement is critical for sperm motility. Without functional dynein, sperm flagella cannot move properly, causing male infertility.