There are approximately alveoli in the adult human lung.
A. 500,000
B. 50 million
C. 500 million
D. 300,000
E. 300 million
E. 300 million
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Amino acid sequences evolve through: (choose all that apply)
A. mutation. B. selection. C. adaptation. D. translation.
Which of the following statements about villi is correct? (Select all correct choices.)
A. Villi can be found in both the jejunum and the ileum. B. Villi serve to increase surface area. C. Villi allow for enhanced nutrient absorption. D. Villi move food particles through the digestive tract. E. Villi secrete multiple types of digestive enzymes.
Polymerase chain reaction (PCR) can be used to perform DNA sequencing reactions. In this case, are two primers (a forward and a reverse) necessary?
A. Yes-you can't perform PCR without two specific primers to amplify the region in question in the DNA. B. No-dideoxynucleotide sequencing depends on different length fragments being formed and then separated based on size. This can take place with only a specific forward OR a specific reverse primer. C. No-you actually need a primer pair for each round of DNA amplification ... so you'll need many, many primer pairs. D. Yes-and it will be important to make sure that the primer pairs are made with dideoxynucleotides that are labeled with fluorescent dyes. Otherwise, you won't be able to detect the fragments that are made in the PCR process.
As a naturalist, you are responsible for training volunteers in the identification of the types of amphibians. The volunteers will use this information to correctly describe the animals to school groups that will visit your nature center. The training documentation for the volunteers lists important characteristics of the different groups of amphibian, but you notice that one of the items on the list is incorrect. Indicate which description is not correct.
A. Frogs and toads have external fertilization whereas salamanders and caecilians have internal fertilization. B. Frogs, toads, and most salamanders have four legs whereas caecilians are legless. C. Frogs and toads lay eggs whereas some caecilians lay eggs and others give birth to live young. D. Salamanders and caecilians have external tails whereas frogs and toads do not. E. Adult frogs, toads, and salamanders are predators of insects and other small animals whereas caecilians are herbivores.