Answer:
False
Explanation:
Cytosine, guanine, thymine, and adenine are collectively referred to as nitrogenous bases. These are not phosphates. The cytosine, guanine, thymine, and adenine are the four different types of nitrogenous bases. These nitrogenous bases are present in the deoxyribonucleotides. Cytosine and thymine are smaller in structure and have single ring structures. These are collectively called pyrimidines. On the other hand, adenine and guanine are the larger nitrogenous bases each with double ring structures. They are collectively called purines
Physical exercise preserves bone mass. Measurements of bone biomarkers may reflect the events in bone during exercise. Fifteen healthy, well-trained individuals (7 men and 8 women) performed a running test for 21 min until exhaustion. Venous blood samples were drawn before and 30 min after the exercise to measure the levels of osteocalcin, the carboxyterminal propeptide of type I procollagen (PICP) and the carboxyterminal cross-linked telopeptide of type I collagen (ICTP). After exercise, the women had a marked increase in serum osteocalcin concentrations (from 7.5±5.0 μg/1 to 11.5±3.0 μg/1), whereas the level was unaffected in the men (from 14.5±3.0 μg/1 to 13.5±4.6 μg/l). In the men there was a marked increase in PICP (from 240±47 μg/1 to 268±56 μg/1) that was not seen in the women (from 244±70 μg/1 to 253±60 μg/1). In neither group did ICTP levels change. In conclusion, significant responses were seen in PICP and osteocalcin during exercise, indicating that such measurements may be valuable for the further delineation of the effects of physical activity on bone. Furthermore, the different responses in men and women point to interesting areas for future studies.
Answer:
Scientists learn how climatic changes during the ice age affected life in this region by analyzing specimens found in these tar pits
Explanation:
La Brea Tar Pits are a group of tar pits in Los Angeles. Many preserved remains of ancient organisms (i.e., fossils) were extracted from the tar, including, among others, Western horses, prehistoric camels, three-toed tapirs, rodent bones, insects, mollusks, wood, plants, etc. The oldest fossils have been dated to be approximately 38,000 years ago by radiometric techniques. Moreover, the Last Glacial Period was the most recent glacial period within the Quaternary glaciation, which encompassed the period between 115,000 to 10,000 years ago. This period (LGP) encompassed the Last Glacial Maximum (LGM), which occurred about 20,000 years ago. In consequence, many of the fossils found in La Brea Tar Pits evidence how the ice age affected life in this region. Moreover, many of the fossil species extracted from the tar are still present today, thereby indicating how these species adapted to fluctuating climatic conditions, whereas certain species couldn't adapt fast enough as the environment changed and therefore they went extinct.
The correct answer is B The young sun's solar winds pushed gases outward to the outer solar system.
