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:
Sertoli cells
Explanation:
The Sertoli cells nourish and protect the developing sperm cells, and spermatogenesis—the developmental pathway from germ cell to mature sperm—occurs in the recesses of the Sertoli cells (Figure 19.17)
Answer:
The correct answer is - 2n = 41 chromosomes.
Explanation:
It is given that the cat has a diploid chromosome number of 38 while the rabbit has a diploid number of 44 chromosomes and if they form a hybrid then their expected chromosome number in somatic cells would be -
Cat (2n=38) produces haploid gametes with 19 chromosomes (n-19).
Rabbit (2n=44) produces haploid gametes with 22 chromosomes(n=22)
19+22= 41 chromosomes in the particular hybrid as half number of chromosomes come from each parent.
Answer:D. Prothetic leg
Explanation:
All the other answer choices are still dreamt of by many scientists and engineers. but you always see people wearing prosthetic legs. D is the obvious answer.
