What does Zinkoff realize about the test he is taking?

It is about himself and is almost fun.

What question on the test stumps Zinkoff?

What do you want to be when you grow up?

What unique characteristic does Hector Binns have?

He wears glasses and cleans his ear with a paper clip.

What does Zinkoff offer to Hector to make a friendship proposal?

He mentions he makes good snickerdoodle cookies.

He promises to help with homework.

He suggests they hang out after school.

He offers to play games together.

What does Zinkoff think best friends do?

They are always together and share experiences.

They compete against each other.

Loser Chapter 18 | Quizalize

Escape from Unsuitable Conditions Some species can survive unfavorable environmental conditions by escaping from them temporarily. For example, desert animals usually hide underground or in the shade during the hottest part of the day. Many desert species are active at night, when temper- atures are much lower. A longer-term strategy is to enter a state of reduced activity, called dormancy, during periods of unfavorable conditions, such as winter or drought. Another strategy is to move to a more favorable habitat, called migration. An example of migration is the seasonal movements of birds, which spend spring and summer in cooler climates and migrate to warmer climates in the fall. THE NICHE Species do not use or occupy all parts of their habitat at once. The specific role, or way of life, of a species within its environment is its niche (NICH). The niche includes the range of conditions that the species can tolerate, the resources it uses, the methods by which it obtains resources, the number of offspring it has, its time of reproduction, and all other interactions with its environment. Parts of a lion’s niche are shown in Figure 18-6. Generalists are species with broad niches; they can tolerate a range of conditions and use a variety of resources. An example of a generalist is the Virginia opossum, found across much of the United States. The opossum feeds on almost anything, from eggs and dead animals to fruits and plants. In contrast, species that have narrow niches are called specialists. An example is the koala of Australia, which feeds only on the leaves of a few species of eucalyptus trees. Some species have more than one niche within a lifetime. For example, caterpillars eat the leaves of plants, but as adult butter- flies, they feed on nectar. Plants and animals are able to share the same habitats because they each have different niches. FIGURE 18-6 niche from the Old French nichier, meaning “to nest” Word Roots and Origins www.scilinks.org Topic: Niche/Habitats Keyword: HM61029 mb06se_iecs02.qxd 5/24/07 10:25 AM Page 365 366 CHAPTER 18 ENERGY TRANSFER All organisms need energy to carry out essential functions, such as growth, movement, maintenance and repair, and reproduction. In an ecosystem, energy flows from the sun to autotrophs, then to organisms that eat the autotrophs, and then to organisms that feed on other organisms. The amount of energy an ecosystem receives and the amount that is transferred from organism to organism affect the ecosystem’s structure. PRODUCERS Autotrophs, which include plants and some kinds of protists and bacteria, manufacture their own food. Because autotrophs cap- ture energy and use it to make organic molecules, they are called producers. Recall that organic molecules are molecules that con- tain carbon. Most producers are photosynthetic, so they use solar energy to power the production of food. However, some autotrophic bacteria do not use sunlight as an energy source. These bacteria carry out chemosynthesis (KEE-moh-SIN-thuh-sis), in which they use energy stored in inorganic molecules to produce carbohydrates. In terres- trial ecosystems, plants are usually the major producers. In aquatic ecosystems, photosynthetic protists and bacteria are usu-

In many cases, cells must move materials from an area of lower concentration to an area of higher concentration, or “up” their concentration gradient. Such movement of materials is known as active transport. Unlike passive transport, active transport requires a cell to expend energy. CELL MEMBRANE PUMPS Ion channels and carrier proteins not only assist in passive trans- port but also help with some types of active transport. The car- rier proteins that serve in active transport are often called cell membrane “pumps” because they move substances from lower to higher concentrations. Carrier proteins involved in facilitated diffusion and those involved in active transport are very similar. In both, the molecule first binds to a specific kind of carrier protein on one side of the cell membrane. Once it is bound to the molecule, the protein changes shape, shielding the molecule from the hydrophobic interior of the phospholipid bilayer. The protein then transports the molecule through the membrane and releases it on the other side. However, cell membrane pumps require energy. Most often the energy needed for active transport is supplied directly or indirectly by ATP. Sodium-Potassium Pump One example of active transport in animal cells involves a carrier protein known as the sodium-potassium pump. As its name sug- gests, this protein transports Na ions and K ions up their con- centration gradients. To function normally, some animal cells must have a higher concentration of Na ions outside the cell and a higher concentration of K ions inside the cell. The sodium- potassium pump maintains these concentration differences. Follow the steps in Figure 5-6 on the next page to see how the sodium-potassium pump operates. First, three Na ions bind to the carrier protein on the cytosol side of the membrane, as shown in step . At the same time, the carrier protein removes a phosphate group from a molecule of ATP. As you can see in step , the phos- phate group from the ATP molecule binds to the carrier protein. Step shows how the removal of the phosphate group from ATP supplies the energy needed to change the shape of the carrier pro- tein. With its new shape, the protein carries the three Na ions through the membrane and then forces the Na ions outside the cell where the Na concentration must remain high. 3 2 1 SECTION 2 OBJECTIVES ● Distinguish between passive transport and active transport. ● Explain how the sodium-potassium pump operates. ● Compare endocytosis and exocytosis. VOCABULARY active transport sodium-potassium pump endocytosis vesicle pinocytosis phagocytosis phagocyte exocytosis www.scilinks.org Topic: Active Transport Keyword: HM60018 mb06se_homs02.qxd 5/18/07 11:02 AM Page 103 104 CHAPTER 5 K+ K+ K+ K+ K+ K+ INSIDE OF CELL OUTSIDE OF CELL Carrier protein Cell membrane P P P P Na+ Na+ Na+ ATP ADP Na+ Na+ Na+ Na+ Na+ Na+ 1 2 3 4 5 6 At this point, the carrier protein has the shape it needs to bind two K ions outside the cell, as step shows. When the K ions bind, the phosphate group is released, as indicated in step , and the carrier protein restores its original shape. As shown in step this time, the change in shape causes the carrier protein to release the two K ions inside the cell. At this point the carrier protein is ready to begin the process again. Thus, a complete cycle of the sodium-potassium pump transports three Na ions out of the cell and two K ions into the cell. At top speed, the sodium-potassium pump can transport about 450 Na ions and 300 K ions per second. The exchange of three Na ions for two K ions creates an electrical gradient across the cell membrane. That is, the outside of the membrane becomes positively charged relative to the inside of the membrane, which becomes relatively negative. In this way, the two sides of the cell membrane are like the positive and nega- tive terminals of a battery. This difference in charge is important for the conduction of electrical impulses along nerve cells. The sodium-potassium pump is only one example of a cell membrane pump. Other pumps work in similar ways to transport important metabolic materials across cell membranes.

History of policing Pre-confederation Mostly informal policing by community residents First police officers Quebec city, mid 17th century Upper Canada, early 19th century Mandate Police conflicts between ethinc groups and employes/labours Maintain moral standards (drunkenness, alcoholism) Apprehend criminals Provincal Police Force Response to disorder resulting form gold strikes in 19th century Replaced by RCMP during 20th century Currently, Ontario,Quebec and parts of Newfoundland have their own provincal police force History of RCMP North-Wesr Mounted Police Founded in 1873 Maintain law and order Ensure orderly settlement in prairies Many problems: desertion, resignation and improper conduct Replaced by Royal Canadain Mounted Police Police Today About 70,000 police officers across Canada 199 police officers per 100,000 population Lower than Scotland (337), England(244), U.S (238) NUmber increased over past decade NUmber of female officers increased 1 out of 5 officers is a women Contemporary Policing Structure of policing Four levels Federal, Provincial, municipal, and First nations Also public transportation police (railway, airport, and transit) Some municipalities have own forces E.g, Peel, Toronoto Others use provincial force detachments or RCMP detachments Royal Candanin Mounted Police Governed by Royal Canadian Mounted Pollcei Act (1985) Broad Range of policing activities, including federal policing and international peacekeppiong Contract Policing Provincial, territorial and municipal level Concerns about local oversight and accountability In but not of communities-difficult to ensure that RCMp detachments are responsive to communities Provincial Police Three forces Ontario Provincial Police Surete du Quebec (SQ) Royal Newfoundland Constabulary (RNC) Other provinces contractually use the RCMP Responsibilities Police rural areas and areas outside municipalities Enforce provincial laws and Criminal Code Regional Police Amalgamated Forces E.g Peel region police and Halton Regional Police Force Provide Police Services to over Half of Ontarians Advantages Cheaper, more servies Disadvantages To centralized, not in touch with community Municipal Police Responsibilites Enforce Criminal Code, Provincal Statues, municipal by laws, some federal statues (e.g drugs) Largest number of officers of any level My be contracted to RCMP or Provincal force Costs are paid by the municipality First Nations Type of policing is negotiated by First Nations Commnity Autonomous reserve based First Nations Officers from RCMP or OPP Responsibilites Enforce Criminal Code, federal and provicanl statues, band bylaws Accountability Reserve based police commission or band council Private Security Services Two main types 1. Private Security Firms 2. Company based, in house security officers No more legal authority than ordinary citizens But can arrest and detain people who commit crimes on private property In Canada, Private security officers outnumber police officer by four to one Parapolice Extension of activities Lack of systems of oversight like transitional police Police Work POlicing The activities of any indivual or organization acting legally on behalf of public or private organizations or persons to maintain security or social order Pluralization of Policing The sharing between public and private security Legislative Framework Carry out tasks within a number of legislative frameworks, define role, powers/responsibilites Canadian charter of rights and freedoms- most impactful on power/actvites of police Provincial and municipal legislation - Status such as motor vehicle administration acts, highway traffic acts, liquor acts and provincial/musincpal police acts Democracy Governance Categories of Policing Recruitment and Training of police officers Police recruitment Recruiting Visible Minorites and Aboriginal People Special initvates and programs for youth, women and visible minorities PEACE (Police Ethnic and Cultureal Exchange) OPPBound (particpate in variety of activate with officer) Toronto POlice recruitment of Somali Officers Edmonton police uniforms that include a hijab Police Training Residential/non-residential academies, centralized and decentralized Physical and academic instruction, socilization into the police occupation Operational field traiing Hands-on application of principles learned in the academy Mentoship form senior officer Working Personality of Police officers Challenges of Police Work Work Enviroment Long hours and shift work Exposure to stressors, especially in high demand environments PTSD and burnout Work Organiztion Harassment of female officers Cumbersome of system of internal redress Summary A number of misconceptions arounds police work, including th emotion that most police work involves crime control A variety of influences on the roles and activities of the police Four levels of policing: federal, provincial, mnicipal and First Nations, each with different responsibilities

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