Q: What are colonies of cells stuck to a surface called? Read this paragraph and choose the correct option from the provided answers: Prokaryotic cells are extremely small and have a variety of shapes. Most have flagella and a cell wall. They have several other cell structures as well. Their DNA exists as large and small loops. Some prokaryotes form biofilms, which are colonies of cells stuck to a surface. Choices: - membranes - cellular coating - membranes - biofilms A:
biofilms
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Q: What is the most common cause of dwarfism? Read this paragraph and choose the correct option from the provided answers: Whereas cystic fibrosis, Tay-Sachs, and phenylketonuria are all autosomal recessive disorders, achondroplasia is an autosomal dominant disorder. Achondroplasia is the most common cause of dwarfism in humans. Achondroplasia is a result of an autosomal dominant mutation in the fibroblast growth factor receptor gene 3 (FGFR3), which causes an abnormality of cartilage formation. FGFR3 normally has a negative regulatory effect on bone growth. In achondroplasia, the mutated form of the receptor is constitutively active (constantly "turned on") and this leads to severely shortened bones. Individuals with achondroplasia are heterozygous for the mutation (one mutant copy, one normal copy). Homozygous for the achondroplasia mutation is lethal prior to birth or shortly after birth. Choices: - deformity - hypothyroidism - retinopathy - achondroplasia A:
achondroplasia
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Q: Carbon-14 dating is a method of what kind of dating? Read this paragraph and choose the correct option from the provided answers: The best-known method of radiometric dating is carbon-14 dating . A living thing takes in carbon-14 (along with stable carbon-12). As the carbon-14 decays, it is replaced with more carbon-14. After the organism dies, it stops taking in carbon. That includes carbon-14. The carbon-14 that is in its body continues to decay. So the organism contains less and less carbon-14 as time goes on. We can estimate the amount of carbon-14 that has decayed by measuring the amount of carbon-14 to carbon-12. We know how fast carbon-14 decays. With this information, we can tell how long ago the organism died. Choices: - orbital - stratigraphy - metamorphic - radiometric A:
radiometric
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Q: What is the force that pulls particles at the exposed surface of a liquid toward other liquid particles called? Read this paragraph and choose the correct option from the provided answers: 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 . Choices: - conservative tension - shinking tension - transfer tension - surface tension A:
surface tension
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