Answer the following question given this paragraph: 10.4 | Nervous System Control of Muscle Tension By the end of this section, you will be able to: Explain concentric, isotonic, and eccentric contractions Describe the length-tension relationship Describe the three phases of a muscle twitch Define wave summation, tetanus, and treppe To move an object, referred to as load, the sarcomeres in the muscle fibers of the skeletal muscle must shorten. The force generated by the contraction of the muscle (or shortening of the sarcomeres) is called muscle tension. However, muscle tension also is generated when the muscle is contracting against a load that does not move, resulting in two main types of skeletal muscle contractions: isotonic contractions and isometric contractions. In isotonic contractions, where the tension in the muscle stays constant, a load is moved as the length of the muscle changes (shortens). There are two types of isotonic contractions: concentric and eccentric. A concentric contraction involves the muscle shortening to move a load. An example of this is the biceps brachii muscle contracting when a hand weight is brought upward with increasing muscle tension. As the biceps brachii contract, the angle of the elbow joint decreases as the forearm is brought toward the body. Here, the biceps brachii contracts as sarcomeres in its muscle fibers are shortening and cross-bridges form; the myosin heads pull the actin. An eccentric contraction occurs as the muscle tension diminishes and the muscle lengthens. In this case, the hand weight is lowered in a slow and controlled manner as the amount of crossbridges being activated by nervous system stimulation decreases. In this case, as tension is released from the biceps brachii, the angle of the elbow joint increases. Eccentric contractions are also used for movement and balance of the body. An isometric contraction occurs as the muscle produces tension without changing the angle of a skeletal joint. Isometric contractions involve sarcomere shortening and increasing muscle tension, but do not move a... Q: An isometric type of what occurs as the muscle produces tension without changing the angle of a skeletal joint? A:
OPTIONS:
- compression
- extension
- acceleration
- contraction
contraction

Answer the following question given this paragraph: Q: Snippet 3: the diploid cells resulting from karyogamy are short-lived and undergo meiosis, producing what? A:
OPTIONS:
- binary spores
- hyperactive spores
- stunted spores
- haploid spores

Answer: haploid spores

Question: Answer the following question given this paragraph: Magnetic poles always occur in pairs of north and southit is not possible to isolate north and south poles. All magnetism is created by electric current. Ferromagnetic materials, such as iron, are those that exhibit strong magnetic effects. The atoms in ferromagnetic materials act like small magnets (due to currents within the atoms) and can be aligned, usually in millimeter-sized regions called domains. Domains can grow and align on a larger scale, producing permanent magnets. Such a material is magnetized, or induced to be magnetic. Above a material's Curie temperature, thermal agitation destroys the alignment of atoms, and ferromagnetism disappears. Electromagnets employ electric currents to make magnetic fields, often aided by induced fields in ferromagnetic materials. Q: Materials, such as iron, that exhibit strong magnetic effects are labeled what? A:
OPTIONS:
- paramagnetic
- superconducting
- ultramagnetic
- ferromagnetic
Answer: ferromagnetic

input with options: Answer the following question given this paragraph: In convection, materials move depending on their heat relative to nearby materials. Q: The process in which materials move depending on their heat relative to nearby materials is known as what? A:
OPTIONS:
- induction
- radiation
- ventilation
- convection
output: convection

Q: Answer the following question given this paragraph: Soil type also influences the type of vegetation that can grow in the region. We can identify climate types by the types of plants that grow there. Q: Along with climate, this also influences the type of vegetation that can grow in the region? A:

OPTIONS:
- gravity
- fertilizer use
- population density
- soil type

A: soil type

Answer the following question given this paragraph: Sponges are filter feeders. They pump water into their body through their pores. The water flows through a large central cavity called the spongocoel (see Figure above ). As the water flows by, specialized collar cells filter out food particles such as bacteria. Collar cells have tiny hairs that trap the particles. They also have a flagellum that whips the water and keeps it moving. Once the food is trapped, the collar cells digest it (see Figure below ). Cells called amebocytes also help digest the food. They distribute the nutrients to the rest of the body as well. Finally, the water flows back out of the body through an opening called the osculum. As water flows through the sponge, oxygen diffuses from the water to the sponge's cells. The cells also expel wastes into the water for removal through the osculum. Q: Filter feeders, such as sponges, pump water into their body through what structures? A:
OPTIONS:
- fibers
- lungs
- valves
- pores
pores