Answer the following question given this paragraph: Echinoderms lack respiratory and excretory systems. Instead, the thin walls of their tube feet allow oxygen to diffuse in and wastes to diffuse out. Echinoderms also lack a centralized nervous system. They have an open circulatory system and lack a heart. On the other hand, echinoderms have a well-developed coelom and a complete digestive system. Echinoderms use pheromones to communicate with each other. They detect the chemicals with sensory cells on their body surface. Some echinoderms also have simple eyes ( ocelli ) that can sense light. Like annelids, echinoderms have the ability to regenerate a missing body part. Q: Echinoderms lack what type of system that in humans consists of the brain and spinal cord? Choices: - autonomic system - endocrine system - peripheral nervous system - centralized nervous system A:
centralized nervous system
(Question)
Answer the following question given this paragraph: Covalent Solids Covalent solids are formed by networks or chains of atoms or molecules held together by covalent bonds. A perfect single crystal of a covalent solid is therefore a single giant molecule. For example, the structure of diamond, shown in part (a) in , consists of sp3hybridized carbon atoms, each bonded to four other carbon atoms in a tetrahedral array to create a giant network. The carbon atoms form six-membered rings. Figure 12.19 The Structures of Diamond and Graphite. Q: Covalent solids are formed by networks or chains of atoms or molecules held together by what? Choices: - ionic bonds - bail bonds - gravitational bonds - covalent bonds A:
(Answer)
covalent bonds
Ques: Answer the following question given this paragraph: Flat-earther is a term used to describe someone who believes something despite the evidence. Or who does not believe something despite the evidence. There are actually people who believe that Earth is flat. They say that satellite photos are faked. They believe that the Apollo Moon landings were faked. But there are very few people alive today who actually believe that Earth is flat. There are, however, plenty of people who can be called flat-earthers. These people believe (or disbelieve) something despite the evidence. Q: Someone who believes something despite the evidence is referred to by what term that references a false belief about our planet? Choices: - geocentric-earther - conspiracy theorist - solid - earther - flat-earther A:
Ans: flat-earther
(Q).
Answer the following question given this paragraph: All gases exert pressure; it is one of the fundamental measurable quantities of this phase of matter. Even our atmosphere exerts pressurein this case, the gas is being "held in" by the earth's gravity, rather than the gas being in a container. The pressure of the atmosphere is about 14.7 pounds of force for every square inch of surface area: 14.7 lb/in2. Pressure has a variety of units. The formal, SI-approved unit of pressure is the pascal (Pa), which is defined as 1 N/m2 (one newton of force over an area of one square meter). However, this is usually too small in magnitude to be useful. A common unit of pressure is the atmosphere (atm), which was originally defined as the average atmospheric pressure at sea level. However, "average atmospheric pressure at sea level" is difficult to pinpoint because of atmospheric pressure variations. A more reliable and common unit is millimeters of mercury (mmHg), which is the amount of pressure exerted by a column of mercury exactly 1 mm high. An equivalent unit is the torr, which equals 1 mmHg. (The torr is named after Evangelista Torricelli, a seventeenth-century Italian scientist who invented the mercury barometer. ) With these definitions of pressure, the atmosphere unit is redefined: 1 atm is defined as exactly 760 mmHg, or 760 torr. We thus have the following equivalences: 1 atm=760 mmHg=760 torr. Q: The pressurized gas of earth's atmosphere is contained by what force? Choices: - variation - light - plasma - gravity A:
(A).
gravity
Ques:Answer the following question given this paragraph: Most mature plant cells have a central vacuole that occupies more than 30% of the cell's volume. The central vacuole can occupy as much as 90% of the volume of certain cells. The central vacuole is surrounded by a membrane called the tonoplast . The central vacuole has many functions. Aside from storage, the main role of the vacuole is to maintain turgor pressure against the cell wall. Proteins found in the tonoplast control the flow of water into and out of the vacuole. The central vacuole also stores the pigments that color flowers. Q: What function does a vacuole do for a cell? Choices: - division - transfer - reproduction - storage A:

Ans:storage
Ques:Answer the following question given this paragraph: The duodenum is the first part of the small intestine. It is also the shortest part. This is where most chemical digestion takes place. Many enzymes and other substances involved in digestion are secreted into the duodenum. Q: The duodenum is the first and the shortest part of what, and is where most chemical digestion takes place? Choices: - rectum - large intestine - stomach - small intestine A:

Ans:
small intestine