<span>The male reproductive parts of a flower is the stamens which are comprised of the anther (which produces pollen) and the filament which supports the anther. The primary purpose of the stamen is to produce pollen which is used to fertilize the female parts of the flower (typically another flower from the same species of plant, but it is possible for some plants to be self fertilizing).</span>
Answer:
A. If the aerobic pathway—cellular respiration—cannot meet the energy demand, then the anaerobic pathway—lactic acid fermentation—starts up, resulting in lactic acid buildup and "oxygen debt."
C. After about 90 seconds of intense exercise, the muscles become depleted of oxygen, and anaerobic respiration can no longer function to produce ATP, resulting in "oxygen debt."
Explanation:
There are two sources of carbohydrates in the human's body for energy (ATP) production. 1) Creatine phosphate and 2) Glycogen. Creatine phosphate metabolizes easily and yields ATP quickly. Whereas glycogen is stored form of carbohydrate which yields energy more slowly. Therefore, initially, our bodies use creatine phosphate and then shift to glycogen. Within 60-90 seconds, the creatinine phosphate in the body is mostly utilized and then energy is produced by the use of glycogen in aerobic pathway. During areobic pathway, oxygen supply is sufficient and per cycle, it produces 32 molecules of ATP. However, when oxygen supply is limited or absent, the body will metabolize glycogen to lactic acid via fermentation and produce only 2 molecules of ATP.
Now consider the example: Kenny hikes all day at a steady pace therefore the supply of oxygen is sufficient for aerobic cellular respiration for ATP production. In this scenario, the oxygen debt is minimal and Kenny relies on aerobic respiration pathway to obtain energy. On the other hand, Janelle runs fast (100 meters in 13.5 seconds) and her cellular respiration would be on the compense of aerobic pathway initially which will be shifted to anaerobic pathway after the supply of oxygen is reduced/minimum. Janelle will heavily rely on the anaerobic pathway because running fast needs energy which cannot be provided via aerobic pathway easily. Therefore, Janelle's body will produce lactic acid and suffer from oxygen debt.
Answer: When the DNA collected on the crime scene is being analysed in the forensic lab, the results will be inconclusive, because error in DNA transcription, particularly in mRNA encoding leads to inheritable phenotype change by reprogramming the transcriptional network, without changing the DNA. Transcription errors are brief with no long-term consequences. Due to mRNA being short-lived and the erroneous proteins are degraded. A decrease in transcription accuracy triggers cellular identity change.
Explanation: This is called epimutation, a heritable modification that results in the change of gene expression, but not the DNA sequence. Epimutation is not associated with DNA mutation, but is associated with the loss or gain of DNA methylation or other heritable changes of the chromatin.
