A geneticist wants to isolate mutants in mice that are defective in nucleotide-excision repair (NER) but is unable to do biochemical analysis on the NER system so must use some other method to identify putative NER mutations. Which of the following would most likely be useful in identifying NER mutations in mice?1. Identifying possible NER mutants by their progeny consisting of a reduced number of females with a normal number of males when they are crossed to normal mice
2. Identifying possible NER mutants by their high spontaneous mutation rates for base-pair substitution and frameshift mutations
3. Identifying possible NER mutants by their increased susceptibility to UV irradiation compared to normal mice
4. Identifying possible NER mutants by their high rate of cytosine deaminations compared to normal mice
5. All of the above would be characteristic of NER nutants

On a recent expedition to a remote region of northern canada, scientists uncovered skeletal remains from about 100,000 years ago. surprisingly, all the skeletal remains, which included many species from differing biological families and spanned about two thousand years, showed evidence of experiencing temperatures in excess of 1000 degrees fahrenheit (or 538 degrees celsius). which of the following, if true, best explains the apparent paradox between the cold environment and the evidence of the bones experiencing hot temperatures? (a) chemical changes that naturally occur during the process of decay in only one north canadian species produce the same evidence of the species' skeletons being exposed to hot temperatures as the expedition scientists found. (b) a little over 103,000 years ago, a large fire is known to have occurred in northern canada. (c) strong evidence exists that as early as 70,000 years ago, homo sapiens around the world relied heavily on fire to cook animals. (d) in the same expedition and in roughly the same layer of excavation, scientists found rudimentary wood cutting and hunting tools used by early humans.

What organ systems are working to you cool down after a workout?

(amoeba sisters video recap: pedigrees and need