*Question*
Answer the following question given this paragraph: 18.4 Leukocytes and Platelets Leukocytes function in body defenses. They squeeze out of the walls of blood vessels through emigration or diapedesis, then may move through tissue fluid or become attached to various organs where they fight against pathogenic organisms, diseased cells, or other threats to health. Granular leukocytes, which include neutrophils, eosinophils, and basophils, originate with myeloid stem cells, as do the agranular monocytes. The other agranular leukocytes, NK cells, B cells, and T cells, arise from the lymphoid stem cell line. The most abundant leukocytes are the neutrophils, which are first responders to infections, especially with bacteria. About 2030 percent of all leukocytes are lymphocytes, which are critical to the body's defense against specific threats. Leukemia and lymphoma are malignancies involving leukocytes. Platelets are fragments of cells known as megakaryocytes that dwell within the bone marrow. While many platelets are stored in the spleen, others enter the circulation and are essential for hemostasis; they also produce several growth factors important for repair and healing. Q: Which leukocytes are first to respond to bacterial infections? Choices: - chemocytes - erythrocytes - microcytes - neutrophils A:
**Answer**
neutrophils

*Question*
Answer the following question given this paragraph: 27.1 | Features of the Animal Kingdom By the end of this section, you will be able to: List the features that distinguish the kingdom Animalia from other kingdoms Explain the processes of animal reproduction and embryonic development Describe the roles that Hox genes play in development Even though members of the animal kingdom are incredibly diverse, most animals share certain features that distinguish them from organisms in other kingdoms. All animals are eukaryotic, multicellular organisms, and almost all animals have a complex tissue structure with differentiated and specialized tissues. Most animals are motile, at least during certain life stages. All animals require a source of food and are therefore heterotrophic, ingesting other living or dead organisms; this feature distinguishes them from autotrophic organisms, such as most plants, which synthesize their own nutrients through photosynthesis. As heterotrophs, animals may be carnivores, herbivores, omnivores, or parasites (Figure 27.2ab). Most animals reproduce sexually, and the offspring pass through a series of developmental stages that establish a determined and fixed body plan. The body plan refers to the morphology of an animal, determined by developmental cues. Q: Because all animals require an external source of what, they are called heterotrophic? Choices: - fuel - energy - water - food A:
**Answer**
food

*Question*
Answer the following question given this paragraph: Power Consumed at Rest The rate at which the body uses food energy to sustain life and to do different activities is called the metabolic rate. The total energy conversion rate of a person at rest is called the basal metabolic rate (BMR) and is divided among various systems in the body, as shown in Table 7.4. The largest fraction goes to the liver and spleen, with the brain coming next. Of course, during vigorous exercise, the energy consumption of the skeletal muscles and heart increase markedly. About 75% of the calories burned in a day go into these basic functions. The BMR is a function of age, gender, total body weight, and amount of muscle mass (which burns more calories than body fat). Athletes have a greater BMR due to this last factor. Q: The rate at which the body uses food energy to sustain life and to do different activities is called the what? Choices: - hormonal rate - calorie rate - life cycle - metabolic rate A:
**Answer**
metabolic rate

*Question*
Answer the following question given this paragraph: Chromosomal alterations are mutations that change chromosome structure. Q: Alterations that change chromosome structure are known as? Choices: - lesions - traits - deformities - mutations A:
**Answer**
mutations