Q: The majority of salamanders lack what organs, so respiration occurs through the skin or through external gills? Read this paragraph and choose the correct option from the provided answers: Modern Amphibians Amphibia comprises an estimated 6,770 extant species that inhabit tropical and temperate regions around the world. Amphibians can be divided into three clades: Urodela ("tailed-ones"), the salamanders; Anura ("tail-less ones"), the frogs; and Apoda ("legless ones"), the caecilians. Urodela: Salamanders Salamanders are amphibians that belong to the order Urodela. Living salamanders (Figure 29.16) include approximately 620 species, some of which are aquatic, other terrestrial, and some that live on land only as adults. Adult salamanders usually have a generalized tetrapod body plan with four limbs and a tail. They move by bending their bodies from side to side, called lateral undulation, in a fish-like manner while "walking" their arms and legs fore and aft. It is thought that their gait is similar to that used by early tetrapods. Respiration differs among different species. The majority of salamanders are lungless, and respiration occurs through the skin or through external gills. Some terrestrial salamanders have primitive lungs; a few species have both gills and lungs. Unlike frogs, virtually all salamanders rely on internal fertilization of the eggs. The only male amphibians that possess copulatory structures are the caecilians, so fertilization among salamanders typically involves an elaborate and often prolonged courtship. Such a courtship allows the successful transfer of sperm from male to female via a spermatophore. Development in many of the most highly evolved salamanders, which are fully terrestrial, occurs during a prolonged egg stage, with the eggs guarded by the mother. During this time, the gilled larval stage is found only within the egg capsule, with the gills being resorbed, and metamorphosis being completed, before hatching. Hatchlings thus resemble tiny adults. Choices: - throats - mouths - noses - lungs A:
lungs

Q: If a machine only changes the direction of a force without changing the ratio of the output/input forces, then what is its associated mechanical advantage? Read this paragraph and choose the correct option from the provided answers: For machines that change only the direction of the force, such as the rope systems on flagpoles, the output force is the same as the input force. Therefore, the mechanical advantage is equal to 1. Choices: - 4 - 1.5 - 2 - 1 A:
1

Q: Q: While smooth muscle tissue can regenerate from stem cells called pericytes, dead cardiac muscle tissue is replaced by what type of tissue? Read this paragraph and choose the correct option from the provided answers: 10.9 Development and Regeneration of Muscle Tissue Muscle tissue arises from embryonic mesoderm. Somites give rise to myoblasts and fuse to form a myotube. The nucleus of each contributing myoblast remains intact in the mature skeletal muscle cell, resulting in a mature, multinucleate cell. Satellite cells help to repair skeletal muscle cells. Smooth muscle tissue can regenerate from stem cells called pericytes, whereas dead cardiac muscle tissue is replaced by scar tissue. Aging causes muscle mass to decrease and be replaced by noncontractile connective tissue and adipose tissue. Choices: - Maximum - embryo tissue - neon tissue - scar tissue A:
A: scar tissue

Question: Q: What type of mammal gives birth to young that need to develop further in the mother's pouch after birth? Read this paragraph and choose the correct option from the provided answers: Marsupials give birth to a tiny, immature embryo. The embryo then continues to grow and develop in a pouch on the mother's belly. This is less risky for the mother. However, the embryo is fragile, so it may be less likely to survive than the fetus of a placental mammal. Choices: - humans - whales - aborigines - marsupials A:
Answer: marsupials

*Question*
Q: What are some uses of chlorine gas? Read this paragraph and choose the correct option from the provided answers: You may be able to avoid some of the health effects of outdoor air pollution by staying indoors on high-pollution days. However, some indoor air is just as polluted as outdoor air. Choices: - washing hands - fueling airplanes - rooting plant cuttings - cleaning, disinfecting and in swimming pools A:
**Answer**
cleaning, disinfecting and in swimming pools

*Question*
Q: What are two examples of lipids? Read this paragraph and choose the correct option from the provided answers: Lipids are organic compounds such as fats and oils. They store energy and help form cell membranes in addition to having other functions in organisms. Choices: - vitamins and fatty acid - adipose tissue and olive oil - defects and oils - fats and oils A:
**Answer**
fats and oils