Answer the following question given this paragraph: When lactose is available, a lactose metabolite called allolactose binds to the allosteric site on the repressor. This interaction causes a conformational change in the repressor shape and the repressor falls off the operator, allowing RNA polymerase to bind to the promoter and initiate transcription. Allolactose is called an inducer because it turns on, or induces the expression of the lac genes. Q: Which inducer turns on the expression of the lac genes? Choices: - xerophyte - glucose - galactose - allolactose A:
allolactose
(Question)
Answer the following question given this paragraph: All living things can sense and respond to stimuli in their environment. Stimuli might include temperature, light, or gravity. Q: What can all living things sense and respond to in their environment? Choices: - sunlight - warmth - wind - stimuli A:
(Answer)
stimuli
Ques: Answer the following question given this paragraph: Muscular dystrophy is a term encompassing a variety of muscle wasting diseases. The most common type, Duchenne Muscular Dystrophy (DMD) , affects cardiac and skeletal muscle, as well as some mental functions. DMD is caused by a defective gene for dystrophin, a protein prevalent in skeletal and cardiac muscles. DMD is an X-linked recessive disorder occurring in 1 in 3,500 male newborns. Because DMD is X-linked, no females are affected. Most affected individuals die before their 20th birthday. Daughters of female carriers of the mutant allele have a 50% chance of also being carriers. Q: What type of disease is muscular dystrophy? Choices: - contagious disease - mutation - infectious disease - a wasting disease A:
Ans: a wasting disease
(Q).
Answer the following question given this paragraph: A familiar example may help you understand the vibrating electric and magnetic fields that make up electromagnetic waves. Consider a bar magnet, like the one in the Figure below . The magnet exerts magnetic force over an area all around it. This area is called a magnetic field. The field lines in the diagram represent the direction and location of the magnetic force. Because of the field surrounding a magnet, it can exert force on objects without touching them. They just have to be within its magnetic field. Q: A magnet can exert force on objects without touching them, as long as they are within what? Choices: - audio field - molecular field - gravitational field - magnetic field A:
(A).
magnetic field
Ques:Answer the following question given this paragraph: Carbon is an element. By itself, it's a black solid. You can see a lump of carbon in Figure below . Carbon is incredibly important because of what it makes when it combines with many other elements. Carbon can form a wide variety of substances. For example, in the air, carbon combines with oxygen to form the gas carbon dioxide. Q: A black solid by itself, this element is incredibly important because of what it makes when it combines with many other elements, including oxygen? Choices: - lead - dioxide - hydrogen - carbon A:

Ans:carbon
Ques:Answer the following question given this paragraph: 10.3 Muscle Fiber Contraction and Relaxation A sarcomere is the smallest contractile portion of a muscle. Myofibrils are composed of thick and thin filaments. Thick filaments are composed of the protein myosin; thin filaments are composed of the protein actin. Troponin and tropomyosin are regulatory proteins. Muscle contraction is described by the sliding filament model of contraction. ACh is the neurotransmitter that binds at the neuromuscular junction (NMJ) to trigger depolarization, and an action potential travels along the sarcolemma to trigger calcium release from SR. The actin sites are exposed after Ca++ enters the sarcoplasm from its SR storage to activate the troponin-tropomyosin complex so that the tropomyosin shifts away from the sites. The cross-bridging of myposin heads docking into actin-binding sites is followed by the "power stroke"the sliding of the thin filaments by thick filaments. The power strokes are powered by ATP. Ultimately, the sarcomeres, myofibrils, and muscle fibers shorten to produce movement. Q: What is the smallest contractile portion of a muscle? Choices: - filaments - cell - capillary - sarcomere A:

Ans:
sarcomere