Trematodes

Campbell Biology Trematodes parasitize a wide range of hosts, and most species have complex life cycles with alternating sexual and asexual stages. Many trematodes require an intermediate host in which larvae develop before infecting the final host (usually a vertebrate), where the adult worms live. For example, various trematodes that parasitize humans spend part ofContinue reading “Trematodes”

Complete Metamorphism of a Butterfly

Campbell Biology (a) The larva (caterpillar) spends its time eating and growing, molting as it grows. (b) After several molts, the larva develops into a pupa. (c) Within the pupa, the larval tissues are broken down, and the adult is built by the division and differentiation of cells that were quiescent in the larva. (d)Continue reading “Complete Metamorphism of a Butterfly”

Computational Chemistry in Drug Design

OpenStax Chemistry While the descriptions of chemical bonding involve many theoretical concepts, they also have many practical, real-world applications. For example, drug design is an important field that uses our understanding of chemical bonding to develop pharmaceuticals. This interdisciplinary area of study uses biology (understanding diseases and how they operate) to identify specific targets, suchContinue reading “Computational Chemistry in Drug Design”

Bulk Feeding in Animals

Campbell Biology Most animals, including humans, are bulk feeders, which eat relatively large pieces of food. Their adaptations include tentacles, pincers, claws, venomous fangs, jaws, and teeth that kill their prey or tear off pieces of meat or vegetation. In this amazing scene, a snake is beginning to swallow another large animal it has capturedContinue reading “Bulk Feeding in Animals”

What is a Baleen?

Many aquatic animals are filter feeders, which strain small organisms or food particles from the surrounding medium. The humpback whale, shown above, is one example. Attached to the whale’s upper jaw are comblike plates called baleen, which remove small invertebrates and fish from enormous volumes of water and sometimes mud. Filter feeding in water isContinue reading “What is a Baleen?”

Stigma and Discrimination Among People Living with HIV

The Lancet HIV 37.9 million people are estimated to be living with HIV, and those on successful antiretroviral therapy (ART) can expect to live a normal lifespan. In 2018 global progress towards the UNAIDS 90-90-90 targets (for 90% of those living with HIV to know their status, 90% of these to be on ART, andContinue reading “Stigma and Discrimination Among People Living with HIV”

Symptoms of Mineral Deficiency in Plants

Campbell Biology The symptoms of a deficiency depend partly on the mineral’s function as a nutrient. For example, a deficiency of magnesium, a component of chlorophyll, causes chlorosis, yellowing of leaves. In some cases, the relationship between a deficiency and its symptoms is less direct. For instance, iron deficiency can cause chlorosis even though chlorophyllContinue reading “Symptoms of Mineral Deficiency in Plants”

Are Plants Computers?

Campbell Biology The picture above is not the creation of a computer genius with a flair for the artistic. It is a head of romanesco, an edible relative of broccoli. Romanesco’s mesmerizing beauty is attributable to the fact that each of its smaller buds resembles in miniature the entire vegetable. Mathematicians refer to such repetitiveContinue reading “Are Plants Computers?”

Muscles of the Arm That Move the Wrists, Hands, and Fingers

OpenStax Anatomy and Physiology The muscles in the anterior compartment of the forearm (anterior flexor compartment of the forearm) originate on the humerus and insert onto different parts of the hand. These make up the bulk of the forearm. From lateral to medial, the superficial anterior compartment of the forearm includes the flexor carpi radialis,Continue reading “Muscles of the Arm That Move the Wrists, Hands, and Fingers”