D236 Pathophysiology - Set 1 - Part 3

Correct Answer: Carrier heterozygotes

Both parents must be carriers with one normal and one sickle cell allele to have an affected child.
Option a is incorrect because affected homozygotes would show disease symptoms, not appear healthy as described for parents.
Option c is incorrect because normal homozygotes couldn't pass sickle cell alleles to produce an affected child described.
Option d is incorrect because compound heterozygotes have two different mutations, not the carrier state for recessive inheritance.

Correct Answer: Trabecular bone tissue

Trabecular or spongy bone in spine, hip, and wrist experiences rapid loss in osteoporosis, explaining these common fracture sites.
Option a is incorrect because cortical bone forms the dense outer layer that's lost more slowly than trabecular bone.
Option c is incorrect because lamellar bone is organized mature bone, not specifically the type most affected initially.
Option d is incorrect because woven bone is immature bone formed during healing, not the primary loss in osteoporosis.

Correct Answer: Positive bacterial culture

Gonorrhea diagnosis requires bacterial culture or nucleic acid testing for Neisseria gonorrhoeae, distinguishing it from other infections.
Option a is incorrect because gonorrhea is bacterial, not viral, so viral cultures would be negative for this infection.
Option c is incorrect because antibody titers indicate exposure but aren't the definitive diagnostic test for active gonorrhea.
Option d is incorrect because gonorrhea is bacterial, not fungal, making fungal testing inappropriate for diagnosis.

Correct Answer: Loss of growth inhibition

Tumor suppressor gene inactivation removes normal growth inhibition, allowing uncontrolled cell proliferation characteristic of cancer development.
Option a is incorrect because cancer cells typically have defective DNA repair, not enhanced repair mechanisms described.
Option c is incorrect because cancer cells avoid apoptosis rather than having increased programmed cell death rates.
Option d is incorrect because cancer cells divide more rapidly, not less, after losing tumor suppressor gene function.

Correct Answer: Ophthalmia neonatorum

Chlamydia can cause ophthalmia neonatorum, a serious eye infection in newborns acquired during vaginal delivery requiring prevention.
Option a is incorrect because congenital cataracts result from intrauterine infections or genetic factors, not chlamydia transmission.
Option c is incorrect because retinal detachment isn't a typical complication of chlamydial infection in newborns described.
Option d is incorrect because congenital glaucoma is a developmental abnormality, not an infectious complication from chlamydia.

Correct Answer: Synovial membrane

The synovial membrane lines joint cavities and produces synovial fluid for lubrication and cartilage nourishment in movable joints.
Option a is incorrect because the joint capsule provides structural support but doesn't produce the synovial fluid described.
Option c is incorrect because articular cartilage receives nourishment from synovial fluid but doesn't produce it itself.
Option d is incorrect because subchondral bone supports cartilage but doesn't produce synovial fluid for joint lubrication.

Correct Answer: X-linked inheritance pattern

X-linked recessive inheritance means carrier mothers pass the condition to sons, explaining the maternal family history pattern.
Option a is incorrect because Y-linked inheritance would only affect males through paternal lines, not maternal family patterns.
Option c is incorrect because autosomal inheritance wouldn't show the sex-linked pattern with primarily male affected individuals described.
Option d is incorrect because mitochondrial inheritance affects all maternal offspring equally, not predominantly males as described.

Correct Answer: Same transmission route

Gonorrhea and chlamydia share sexual transmission routes and risk factors, leading to frequent coinfection requiring dual treatment.
Option b is incorrect because these are different organisms without cross resistance, though they share transmission routes described.
Option c is incorrect because while one infection may facilitate another, the primary reason is shared transmission route.
Option d is incorrect because treatment interactions don't explain why these infections frequently occur together initially.

Correct Answer: Osteoclast cells

Osteoclasts resorb excess bone during remodeling, refining callus into normal bone architecture after fracture healing completion.
Option a is incorrect because osteoblasts build new bone but don't remove excess material during the remodeling phase.
Option c is incorrect because chondrocytes produce cartilage in early healing but don't participate in bone remodeling.
Option d is incorrect because fibroblasts produce connective tissue but don't resorb bone during architectural remodeling described.

Correct Answer: Maternal exclusive transmission

Mitochondrial DNA transmits exclusively through mothers, allowing clear maternal inheritance pattern tracking for associated diseases affecting offspring.
Option a is incorrect because while true, the key advantage is tracking maternal lineages, not just absent paternal contribution.
Option c is incorrect because rapid mutation rates complicate analysis rather than providing advantages for inheritance studies.
Option d is incorrect because nuclear independence is a characteristic but not the main advantage for studying inheritance patterns.