According to the fossil record, which of the following jawed fishes diversified in the Devonian and Carboniferous periods, but left no direct descendants?
a. placoderms
b. ostracoderms
c. osteolepiforms
d. conodonts
Ans: a. placoderms
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Adrenoleukodystrophy (ALD) is a fatal disease that results from the inability of liver cells to transport very long chain fatty acids (VLCFAs) across the peroxisomal membrane. It is diagnosed by the presence of high levels of VLFCAs in the blood. The disease results in destruction of brain myelin leading to progressive cognitive impairment, coma, and death by the age of 14. ALD is an X-linked recessive condition, and there has never been a case of ALD described in girls. You have just started your internship at the Mayo clinic and a 10-year-old girl comes in who is in a coma and having seizures. Blood tests show she has extremely elevated levels of long-chain fatty acids. This looks like ALD, but a girl has never been afflicted. When you go to your supervisor to give your diagnosis, which
of the following hypotheses do you present to support it? A. The patient's mother and father are both recessive carriers of ALD. B. Most of the Barr bodies in the patient's liver have a normal peroxisome gene. C. The patient's mother is a carrier for ALD. D. The patient has Turner syndrome. E. The patient's mother is a carrier, and the young girl has either only genetically normal Barr bodies in the liver or the girl has Turner syndrome.
Vitamins are ________ substances and minerals are ________ substances that perform essential metabolic functions
a. inessential / essential b. organic / inorganic c. essential / inessential d. inorganic / organic
Fungi are heterotrophs that feed off decaying matter. What is the term for this type of feeder?
a. saprobes b. mycophytes c. caprophiles d. chemolithotrophs
Hemophilia is a group of different inherited blood-clotting disorders. Which is true about hemophilia?
A. It causes sterility. B. It is more common in males than in females. C. It is inherited only on the autosomes. D. It is more common in females than in males.