Answer the following question given this paragraph: Types of Receptors Receptors are protein molecules in the target cell or on its surface that bind ligand. There are two types of receptors, internal receptors and cell-surface receptors. Internal receptors Internal receptors, also known as intracellular or cytoplasmic receptors, are found in the cytoplasm of the cell and respond to hydrophobic ligand molecules that are able to travel across the plasma membrane. Once inside the cell, many of these molecules bind to proteins that act as regulators of mRNA synthesis (transcription) to mediate gene expression. Gene expression is the cellular process of transforming the information in a cell's DNA into a sequence of amino acids, which ultimately forms a protein. When the ligand binds to the internal receptor, a conformational change is triggered that exposes a DNA-binding site on the protein. The ligand-receptor complex moves into the nucleus, then binds to specific regulatory regions of the chromosomal DNA and promotes the initiation of transcription (Figure 9.4). Transcription is the process of copying the information in a cells DNA into a special form of RNA called messenger RNA (mRNA); the cell uses information in the mRNA (which moves out into the cytoplasm and associates with ribosomes) to link specific amino acids in the correct order, producing a protein. Internal receptors can directly influence gene expression without having to pass the signal on to other receptors or messengers. Q: What type of receptors, also known as intracellular or cytoplasmic receptors, are found in the cytoplasm of the cell and respond to hydrophobic ligand molecules that are able to travel across the plasma membrane? Choices: - external - essential - mechanical - internal A:
internal
(Question)
Answer the following question given this paragraph: At what population size does growth start to slow in the logistic model of growth? That depends on the population's carrying capacity (see Figure above ). The carrying capacity (K) is the largest population size that can be supported in an area without harming the environment. Population growth hits a ceiling at that size in the logistic growth model. Q: The largest population size that can be supported in an area without harming the environment is referred to as what? Choices: - population shift - containing capacity - population density - carrying capacity A:
(Answer)
carrying capacity
Ques: Answer the following question given this paragraph: The direct conversion of a solid to a gas, without an intervening liquid phase, is calledsublimation. The amount of energy required to sublime 1 mol of a pure solid is theenthalpy of sublimation (Hsub). Common substances that sublime at standard temperature and pressure (STP; 0C, 1 atm) include CO2 (dry ice); iodine (Figure 11.18 "The Sublimation of Solid Iodine"); naphthalene, a substance used to protect woolen clothing against moths; and 1,4-dichlorobenzene. As shown in Figure 11.17 "The Three Phases of Matter and the Processes That Interconvert Them When the Temperature Is Changed", the enthalpy of sublimation of a substance is the sum of its enthalpies of fusion and vaporization provided all values are at the same T; this is an application of Hess's law. (For more information about Hess's law, see Chapter 5 "Energy Changes in Chemical Reactions", Section 5.2 "Enthalpy"). Equation 11.3. Q: The direct conversion of a solid to a gas, without an intervening liquid phase, is called what? Choices: - amplification - isolation - insertion - sublimation A:
Ans: sublimation
(Q).
Answer the following question given this paragraph: The chloroplast is the site of photosynthesis. Part of the photosynthesis reactions occur in an internal membrane within the organelle. Many of the pigments and other molecules necessary for photosynthesis are embedded within these internal membranes, The chloroplast contains many of these internal membranes, allowing numerous photosynthetic reactions to occur simultaneously, and making photosynthesis very efficient. These internal membranes stack on top of each other, just like a stack of pancakes. Q: Where is the site of photosynthesis? Choices: - another chloroplast - the chloroburst - the organism - the chloroplast A:
(A).
the chloroplast
Ques:Answer the following question given this paragraph: 20.2 Alcohols and Ethers Many organic compounds that are not hydrocarbons can be thought of as derivatives of hydrocarbons. A hydrocarbon derivative can be formed by replacing one or more hydrogen atoms of a hydrocarbon by a functional group, which contains at least one atom of an element other than carbon or hydrogen. The properties of hydrocarbon derivatives are determined largely by the functional group. The OH group is the functional group of an alcohol. The ROR group is the functional group of an ether. 20.3 Aldehydes, Ketones, Carboxylic Acids, and Esters Functional groups related to the carbonyl group include the CHO group of an aldehyde, the CO group of a ketone, the CO2H group of a carboxylic acid, and the CO2R group of an ester. The carbonyl group, a carbon-oxygen double bond, is the key structure in these classes of organic molecules: Aldehydes contain at least one hydrogen atom attached to the carbonyl carbon atom, ketones contain two carbon groups attached to the carbonyl carbon atom, carboxylic acids contain a hydroxyl group attached to the carbonyl carbon atom, and esters contain an oxygen atom attached to another carbon group connected to the carbonyl carbon atom. All of these compounds contain oxidized carbon atoms relative to the carbon atom of an alcohol group. 20.4 Amines and Amides The addition of nitrogen into an organic framework leads to two families of molecules. Compounds containing a nitrogen atom bonded in a hydrocarbon framework are classified as amines. Compounds that have a nitrogen atom bonded to one side of a carbonyl group are classified as amides. Amines are a basic functional group. Amines and carboxylic acids can combine in a condensation reaction to form amides. Q: Compounds containing an atom of what element, bonded in a hydrocarbon framework, are classified as amines? Choices: - oxygen - hydrogen - ammonia - nitrogen A:

Ans:nitrogen
Answer the following question given this paragraph: Two unique properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like the water droplet that has formed on the leaky faucet pictured in the Figure below . You can learn more about surface tension at this URL: http://io9. com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension . Q: What is the force that pulls particles at the exposed surface of a liquid toward other liquid particles called? Choices: - conservative tension - shinking tension - transfer tension - surface tension A:
surface tension