ob/ob mice
What will be an ideal response?
Mice that are homozygous for the mutant ob gene; their body fat produces no leptin, and they become very obese; discovered in 50s
> eat more than control mice; they convert calories to fat more efficiently, and they use their calories more efficiently
> Coleman hypothesized that they lack a critical hormone that normally inhibits fat production and maintenance
> in 1994, Friedman characterized and cloned the gene that is mutated in ob/ob mice
> found this gene expressed only in fat cells, and they characterized the protein it normally encodes, a peptide hormone they named leptin
>SO because of the mutation, the mice lacked leptin
> led to exciting hypothesis that perhaps leptin is a negative feedback signal normally released from fat stores to decrease appetite and increase fat metabolism
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Your botany instructor likes to tell nerdy jokes, like this: "I wanted to buy a pink Toyota Corolla, but the dealer only had a green Calyx available." Impress your instructor with a clever response to this joke.
A. "Oh, I would have chosen the blue Receptacle." B. "Those are great cars, but the pinecone tires don't roll very well." C. "Me too! But I could only afford the yellow Androecium." D. "The factory must have run out of class A genes." Clarify Question What is the key concept addressed by the question? What type of thinking is required? Gather Content What do you already know about flower anatomy? What other information is related to the question? Choose Answer Given what you now know, what information is most likely to produce the correct answer? Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
People with albinism carry two copies of the ____________________ allele (aa) and cannot make a pigment called
____________________ which is the principal pigment in skin, hair and eye color. Fill in the blank(s) with the appropriate word(s).
homeostasis
What will be an ideal response?
Motor neurons
A) carry impulses to the brain. B) send signals to effector organs. C) transmit impulses toward the spinal cord. D) receive stimuli from inside or outside the body. E) integrate information from many sources.