Answer the following question given this paragraph: A unique feature of echinoderms is their water vascular system . This is a network of canals that extend along each body part. In most echinoderms, the canals have external projections called tube feet (see Figure below ). The feet have suckers on the ends. Muscle contractions force water into the feet, causing them to extend outward. As the feet extend, they attach their suckers to new locations, farther away from their previous points of attachment. This results in a slow but powerful form of movement. The suckers are very strong. They can even be used to pry open the shells of prey. Q: What makes echinoderms force water into the feet and move forward? Choices: - spring contractions - vacuum contractions - field contractions - muscle contractions A:
muscle contractions
(Question)
Answer the following question given this paragraph: Hydrogen sulfide is a noxious and toxic gas produced from decaying organic matter that contains sulfur. A lethal concentration in rats corresponds to an inhaled dose of 715 molecules per million molecules of air. How many molecules does this correspond to per mole of air? How many moles of hydrogen sulfide does this correspond to per mole of air?. Q: Hydrogen sulfide is a noxious and toxic gas produced from decaying organic matter that contains what? Choices: - tin - methane - helium - sulfur A:
(Answer)
sulfur
Ques: Answer the following question given this paragraph: An ionic bond forms when the metal sodium gives up an electron to the nonmetal chlorine. Q: What forms when the metal sodium gives up an electron to the nonmetal chlorine? Choices: - covalent bond - van der waals force - hydrogen bond - an ionic bond A:
Ans: an ionic bond
(Q).
Answer the following question given this paragraph: The cytoplasm consists of watery cytosol and cell structures. It has several functions. The cytoskeleton is the "skeleton" of the cell. It helps the cell keep its shape. Q: What is the skeleton of the cell? Choices: - cytoplasm - cell membrane - cell wall - cytoskeleton A:
(A).
cytoskeleton
Ques:Answer the following question given this paragraph: Since natural selection acts on the phenotype, if an allele causes death in a homozygous individual, aa , for example, it will not cause death in a heterozygous Aa individual. These heterozygous Aa individuals will then act as carriers of the a allele, meaning that the a allele could be passed down to offspring. People who are carriers do not express the recessive phenotype, as they have a dominant allele. This allele is said to be kept in the population's gene pool. The gene pool is the complete set of genes and alleles within a population. Q: What is the term for the complete set of genes and alleles within a population? Choices: - the ancestral pool - the chromosomal pool - the biodiversity pool - the gene pool A:

Ans:the gene pool
Ques:Answer the following question given this paragraph: Contact metamorphism occurs when a rock is altered by heat from a nearby magma. Q: When a rock is altered by heat from a nearby magma, what occurs? Choices: - sublimation - evaporation - form metamorphism - contact metamorphism A:

Ans:
contact metamorphism