Answer the following question given this paragraph: Some animals change their depth by changing their density. Recall that things that are denser than their surroundings sink while those that are less dense than their surroundings float. Most fish have a swim bladder, a special sac that is filled with gases from their blood. When the fish's swim bladder is full, it is less dense than the surrounding water and the fish will rise towards the surface. Another property of water that affects lakes is the unique changes in density during phase changes. The density of most substances increases when a liquid becomes a solid. This is not so for water: Solid water is actually less dense than liquid water. It is for this reason that ice floats. Can you imagine a world where ice sank? Lakes would freeze from the bottom up, killing many fish. Frozen water in the Polar Regions would sink and change the ocean levels. The fact that ice floats is essential for the survival of many aquatic ecosystems and ultimately life on Earth. Besides the changes in density, there are other ways in which the phase changes of water have significant impacts. When water is trapped in small cracks in rocks, it will expand as it freezes and break up the rock causing weathering. The transpiration (evaporation) of water from a good-sized tree can move 1800 liters of water out of the ground in a single day. Sublimation, the phase change between solid and gas, is responsible for the formation of frost. As you can see, water has many special properties that make its role in nature unique. It is considered the "universal solvent" because its bipolar molecule enables it to dissolve a wide variety of substances. Water is the only substance that occurs naturally in all three states; solid, liquid, and gas. Water is truly a miracle for life!. Q: How do some animals change their depth? Choices: - mass migration - metamorphosis - spontaneous mutations - by changing their density A:
by changing their density
Answer the following question given this paragraph: 31.3 Peripheral nervous system The peripheral nervous system is broken down into two sub-systems, the somatic nervous system and the autonomic nervous system. ANS - Autonomic Nervous System The ANS has two components - parasympathetic and sympathetic. The sympathetic nervous system is the "fight or flight" or fright response and results in an increased heart rate, increased rate of breathing, and an elevated blood glucose level. There is also decreased digestion. The second neurotransmitter is epinephrine. In this case, the first neuron is short and the second neuron is long. The parasympathetic nervous system is the rest and digest system. Drugs must be able to pass the blood brain barrier to have an effect on the CNS. Drugs act by affecting the neuron and how likely it is to fire an action potential. Stroke occurs when there is a blood clot that goes to the brain and prevent blood flow. Q: What are the two components of the autonomic nervous system? Choices: - empathetic and sympathetic - crystallisation and sympathetic - neurons and sympathetic - parasympathetic and sympathetic A:
parasympathetic and sympathetic
Q: Answer the following question given this paragraph: Many STIs are caused by bacteria. Some of the most common bacterial STIs are chlamydia, gonorrhea, and syphilis. Bacterial STIs can be cured with antibiotics. Q: What are most stis caused by? Choices: - vaccines - parasites - viruses - bacteria A:
A: bacteria
Question: Answer the following question given this paragraph: Ionic substances dissociate into ions when they dissolve in water, but most molecular substances do not. Q: What substances dissociate into ions when dissolved in water? Choices: - isotopes - magnetic - solvent - ionic A:
Answer: ionic
*Question*
Answer the following question given this paragraph: The dermis is the lower layer of the skin, located directly beneath the epidermis (see Figure below ). It is made of tough connective tissue and attached to the epidermis by collagen fibers. The dermis contains blood vessels and nerve endings. Because of the nerve endings, skin can feel touch, pressure, heat, cold, and pain. The dermis also contains hair follicles and two types of glands. Q: What layer of skin is located right beneath the epidermis? Choices: - cusps - scars - humus - dermis A:
**Answer**
dermis
Answer the following question given this paragraph: Every chemical reaction occurs with a concurrent change in energy. Q: Every chemical reaction occurs with a concurrent change in what? Choices: - neutrons - mass - hydrogen - energy A:
energy