Answer the following question given this paragraph: The muscular system consists of all the muscles of the body. Muscles are organs composed mainly of muscle cells, which are also called muscle fibers . Each muscle fiber is a very long, thin cell that can do something no other cell can do. It can contract, or shorten. Muscle contractions are responsible for virtually all the movements of the body, both inside and out. There are three types of muscle tissues in the human body: cardiac, smooth, and skeletal muscle tissues. They are shown in Figure below and described below. Q: What are muscle cells in the muscles called? Choices: - human fibers - use fibers - job fibers - muscle fibers A:
muscle fibers
Answer the following question given this paragraph: Evolution can be described as a change in species over time . Dinosaur fossils are significant evidence of evolution and of past life on Earth. Q: What term refers to a change in species over time? Choices: - spontaneous change - generation - mutation - evolution A:
evolution
Q: Answer the following question given this paragraph: 6. Sound energy is a form of mechanical energy that starts with a vibration in matter. For example, the singer's voice starts with vibrations of his vocal cords, which are folds of tissue in his throat. The vibrations pass to surrounding particles of matter and then from one particle to another in waves. Sound waves can travel through air, water, and other substances, but not through empty space. Q: What is a form of mechanical energy that starts with a vibration in matter? Choices: - solar energy - electrical energy - industrial energy - sound energy A:
A: sound energy
Question: Answer the following question given this paragraph: Puberty lasts from about ages 12 to 18 years and is controlled by hormones. Q: What chemical affects the onset of puberty and duration? Choices: - steroids - enzymes - acids - hormones A:
Answer: hormones
*Question*
Answer the following question given this paragraph: Q: Each microspore develops into a pollen grain containing a male what? Choices: - progesterone - zygote - sperm - gametophyte A:
**Answer**
gametophyte
Answer the following question given this paragraph: What causes puberty to begin? The hypothalamus in the brain "tells" the pituitary gland to secrete hormones that target the testes. The main pituitary hormone involved is luteinizing hormone (LH) . It stimulates the testes to secrete testosterone. Testosterone, in turn, promotes protein synthesis and growth. It brings about most of the physical changes of puberty, some of which are shown in Figure below . In addition to the changes shown below, during puberty male facial hair begins to grow, the shoulders broaden, and the male voice deepens. You can watch an animation of these and other changes that occur in boys during puberty at the Interactive Body link: http://www. bbc. co. uk/science/humanbody/body/interactives/lifecycle/teenagers/ . Q: What hormone, which is associated with luteinizing hormone and male sexuality, helps bring about physical changes in puberty? Choices: - steroids - epinephrine - estrogen - testosterone A:
testosterone