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:
Mitosis is first and the ending product is 2 new nuclei and cytokinesis is last and the ending is two new cells.
Explanation: Hope this helps<3
Answer:
10 chromosomes/sister chromatids
Explanation:
Prophase is the first stage of cell division (mitosis). Prior to the cell entering the actual division stage, it undergoes a phase where it prepares its content and most importantly undergo the duplication of its genetic material (DNA). This DNA are found as chromosomes. It undergoes replication of its DNA in the S-phase of interphase stage.
Since Arabidopsis thaliana has 10 chromosomes, and each chromosome holds one DNA molecule, 10 molecules of DNA will be present in the mustard plant's genome. These 10 molecules of DNA will be replicated on another copy of chromosome which is identical to the template. This chromosomes are called SISTER chromatids i.e. replicated chromosome. Each sister chromatids are held together at the centromere and are considered one individual chromosome until they separate during anaphase stage.
Hence, at the Prophase stage, before separation, each sister chromatid (replicated chromosome) is considered as one chromosome. Thus, in the mustard plant with 10 chromosomes, it will possess 10 sister chromatids or chromosomes at the Prophase stage.
N.B: When sister chromatids separate during anaphase stage, they will be regarded as individual chromosomes.
Answer: Clathrin cages assemble, vesicles form but cannot be pinched of but no disassembly occurs so the vesicles remain coated in clathrin.
Explanation:
Endocytosis is a cellular mechanism that allows the introduction of extracellular material into the cell. Clathrin-coated vesicles act to incorporate different molecules that are recognized by specific proteins located in the clathrin-coated pits. Upon invagination of a portion of the plasma membrane, the material is transported to its final intracellular destination.
<u>Clathrin is a protein that forms the lining of cell membrane microcavities where various receptors are located. Once a particle is recognized by the receptors, invagination of the plasma membrane occurs, which then fuses to form an endocellular vesicle.</u> When vesicle budding occurs, the vesicle is detached from its attachment to the membrane with the help of a GTPase protein called dynamin. Then, the vesicle is freed from clathrin by the action of a type of ATP-ase called Hsp70-ATP and docks to late endosomes that are immediate precursors of lysosomes, fusing the membranes of both. The fission of the clathrin-coated vesicle is controlled by the GTPase dynamin and it has been proposed that dynamin acts by generating the necessary force to strangle the "neck" and cleave the vesicles from the membrane. So they are mainly involved in the cleavage of newly formed vesicles from the membrane of one cell compartment, their orientation, and their fusion with another compartment. Also, without the dynamin, vesicles are not freed from clathrin.
<u>In the absence of dynamin, vesicles are formed but the membrane fusion or pinching off will not occur. Then, invaginated coated pits will be found.</u>
