What would be a likely result if all the bees and butterflies in an area were destroyed?

Correct Answer: D

Rationale: Bees and butterflies are vital pollinators, transferring pollen between flowers to enable fertilization and seed production in plants like fruits and vegetables. Their absence halts pollination, reducing seed output, as many plants can't self-pollinate effectively. Birds may rely on seeds, but their food need isn't the direct issue. More flowers or seeds contradict pollination's loss. Fewer seeds, a direct consequence, impacts ecosystems and agriculture, highlighting pollinators' critical role in reproduction.

Correct Answer: D

Rationale: In muscle cells, specialized terminology distinguishes structures. The plasma membrane, enveloping the cell, is the sarcolemma sarco meaning flesh, lemma a sheath serving as the boundary for nerve signal transmission and ion exchange. Sarcoplasm is the cytoplasm, sarcomeres are contractile units within myofibrils, and the sarcoplasmic reticulum stores calcium. The sarcolemma's role in action potential propagation, via T-tubules, initiates contraction, setting it apart from internal components. This unique naming reflects muscle cells' adaptation for rapid, coordinated responses, essential in physiology for understanding excitation-contraction coupling.

Correct Answer: C

Rationale: A sarcomere is the contractile unit of muscle, a segment of a myofibril between Z-lines, containing overlapping actin and myosin myofilaments. It's not a cancer (sarcoma), cytoplasm (sarcoplasm), or membrane (sarcolemma), but a structural section where sliding filaments shorten during contraction. Defining myofibril organization, sarcomeres' repetitive nature enables muscle shortening, distinguishing them from pathological or cellular envelope terms, central to understanding muscle mechanics at the microscopic level.

Correct Answer: A

Rationale: The deltoid, in the upper arm's shoulder region, is a standard intramuscular injection site due to its accessible, thick muscle mass, minimizing nerve damage risk. Gluteus maximus is avoided to protect the sciatic nerve (gluteus medius is preferred), vastus medialis isn't typical, and latissimus dorsi, on the back, lacks suitable mass and access. Deltoid's prominence and safety distinguish it in clinical practice, key for effective drug delivery.

Correct Answer: A

Rationale: Both cardiac and skeletal muscle cells display striations banded patterns from sarcomere alignment unlike smooth muscle. Intercalated discs, branching, and involuntary control are cardiac-specific, aiding heart synchronization and automaticity. Striations reflect shared contractile machinery, distinguishing them from non-striated smooth muscle, key to their histological and functional similarity.