BIOS 256 Week 7 Genetics and Inheritance

Grace J.
August 6, 2025August 6, 2025
BIOS-256, CU BSN

Student Name

Chamberlain University

BIOS-256: Anatomy & Physiology IV with Lab

Prof. Name

Date

Genetics and Inheritance

1. Define genotype.

A genotype refers to the specific genetic makeup of an organism in terms of the alleles inherited from its parents. Alleles are different forms of a gene that can influence particular traits. The combination of these alleles—one from each parent—determines an individual’s genotype. This genetic composition governs whether certain traits will be expressed or remain recessive, even if they are present in the genetic code (Saladin, 2020).

2. Define phenotype.

Phenotype refers to the observable physical or biochemical characteristics of an organism that result from the interaction between its genotype and the environment. These traits can include features such as eye color, height, or specific characteristics like the presence or absence of a cleft chin. While the genotype provides the blueprint, the phenotype represents the visible or measurable expression of those genetic instructions (Saladin, 2020).

3. What gene mutation is associated with cystic fibrosis? How does this affect mucus production?

Cystic fibrosis (CF) is caused by mutations in the CFTR gene, which stands for cystic fibrosis transmembrane conductance regulator. This gene encodes a protein that helps regulate the movement of salt and water in and out of cells. Mutations in the CFTR gene lead to the production of a malfunctioning protein, disrupting the normal hydration of mucus. As a result, mucus becomes thick and sticky, leading to blockages in various organs. Furthermore, individuals with CF often have saltier sweat due to the disrupted regulation of sodium and chloride ions (U.S. Department of Health and Human Services, n.d.).

4. How is cystic fibrosis inherited?

Cystic fibrosis follows an autosomal recessive inheritance pattern. This means that a child must inherit two copies of the mutated CFTR gene—one from each parent—to develop the disease. Individuals who inherit only one defective gene are carriers; they typically do not exhibit symptoms but can pass the gene to their offspring (U.S. Department of Health and Human Services, n.d.).

5. Describe 3 problems that a patient with cystic fibrosis may have—choose 1 problem from 3 different body systems.

Body System	Problem Associated with Cystic Fibrosis	Description
Skeletal System	Bone Density Loss	Individuals with CF often experience reduced bone mass and low body weight due to impaired osteoblast function. The defective CFTR protein indirectly increases osteoclast activity, which weakens bone structure (Stalvey & Clines, 2013).
Respiratory System	Chronic Lung Infections and Pulmonary Complications	The accumulation of thick mucus in the airways leads to persistent respiratory infections, lung damage, and, in severe cases, partial lung collapse (Saladin, 2020).
Reproductive System	Infertility in Males	Up to 95% of males with CF are infertile due to congenital bilateral absence of the vas deferens (CBAVD), a condition directly linked to the disease (Popli & Stewart, 2007).

References

Popli, K., & Stewart, J. (2007). Infertility and its management in men with cystic fibrosis: Review of literature and clinical practices in the UK. Human Fertility, 10(4), 217–221. https://doi.org/10.1080/14647270701510033

Saladin, K. S. (2020). Anatomy & Physiology: The Unity of Form and Function (9th ed.). McGraw-Hill Higher Education (US). https://ambassadored.vitalsource.com/books/9781260791563