Answer the following question given this paragraph: A catalyst works by providing a lower energy pathway from reactants to products. The use of a catalyst involves intermediate reactions which have lower activation complexes than the original reaction. On a simplified reaction energy diagram, this can be thought of as lowering the activation energy for a given transformation. If the activation energy of a reaction is decreased, more collisions will have enough energy to overcome this lower barrier, so the reactant-to-product transformation will occur more frequently. As a result, the overall reaction rate will be higher than for an identical reaction with a larger activation energy barrier. Q: What works by providing a lower energy pathway from reactants to products? Choices: - thermodynamics - hormones - magnetism - catalyst A:
catalyst
(Question)
Answer the following question given this paragraph: Cellular respiration and photosynthesis are important parts of the carbon cycle. The carbon cycle is the pathways through which carbon is recycled in the biosphere. While cellular respiration releases carbon dioxide into the environment, photosynthesis pulls carbon dioxide out of the atmosphere. The exchange of carbon dioxide and oxygen during photosynthesis ( Figure below ) and cellular respiration worldwide helps to keep atmospheric oxygen and carbon dioxide at stable levels. Q: Cellular respiration and photosynthesis are important parts of which cycle? Choices: - vapor cycle - greenhouse effect - water cycle - carbon cycle A:
(Answer)
carbon cycle
Ques: Answer the following question given this paragraph: When heat is positive, the total energy of the system is increasing. Q: What happens to the total energy of the system when heat is positive? Choices: - nothing - it remains constant - it decreases - it increases A:
Ans: it increases
(Q).
Answer the following question given this paragraph: Some athletes attempt to boost their performance by using artificial hormones that enhance muscle performance. Anabolic steroids, a form of the male sex hormone testosterone, are one of the most widely known performance-enhancing drugs. Steroids are used to help build muscle mass. Other hormones that are used to enhance athletic performance include erythropoietin, which triggers the production of red blood cells, and human growth hormone, which can help in building muscle mass. Most performance enhancing drugs are illegal for non-medical purposes. They are also banned by national and international governing bodies including the International Olympic Committee, the U. Olympic Committee, the National Collegiate Athletic Association, the Major League Baseball, and the National Football League. The side effects of synthetic hormones are often significant and non-reversible, and in some cases, fatal. Androgens produce several complications such as liver dysfunctions and liver tumors, prostate gland enlargement, difficulty urinating, premature closure of epiphyseal cartilages, testicular atrophy, infertility, and immune system depression. The physiological strain caused by these substances is often greater than what the body can handle, leading to unpredictable and dangerous effects and linking their use to heart attacks, strokes, and impaired cardiac function. Regulation of the Female Reproductive System In females, FSH stimulates development of egg cells, called ova, which develop in structures called follicles. Follicle cells produce the hormone inhibin, which inhibits FSH production. LH also plays a role in the development of ova, induction of ovulation, and stimulation of estradiol and progesterone production by the ovaries, as illustrated in Figure 37.9. Estradiol and progesterone are steroid hormones that prepare the body for pregnancy. Estradiol produces secondary sex characteristics in females, while both estradiol and progesterone regulate the menstrual cycle. Q: Anabolic steroids, a form of the male sex hormone testosterone, are one of the most widely known performance-enhancing drugs. steroids are used to help build what? Choices: - bone mass - nervous tissue - brain tissue - muscle mass A:
(A).
muscle mass
Ques:Answer the following question given this paragraph: Q: What is the term for the basic contractile unit of the muscle? Choices: - filament - sphincter - bandimere - sarcomere A:

Ans:sarcomere
Ques: Answer the following question given this paragraph: The diatoms are unicellular photosynthetic protists that encase themselves in intricately patterned, glassy cell walls composed of silicon dioxide in a matrix of organic particles (Figure 23.18). These protists are a component of freshwater and marine plankton. Most species of diatoms reproduce asexually, although some instances of sexual reproduction and sporulation also exist. Some diatoms exhibit a slit in their silica shell, called a raphe. By expelling a stream of mucopolysaccharides from the raphe, the diatom can attach to surfaces or propel itself in one direction. Q: The diatoms are unicellular photosynthetic protists that encase themselves in intricately patterned, glassy cell walls composed of silicon dioxide in a matrix of organic particles. these protists are a component of freshwater and these? Choices: - waste plankton - land plankton - source plankton - marine plankton A:
Ans:
marine plankton