<span> cell - A membrane bound structure that is the basic unit of life
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- Xylem contains tracheids, vessels, xylem parenchyma and xylem fibre.
- Tracheids: They are elongated, tubular dead cells with tapering end walls.
- Vessels: These are also known as trachea. They are elongated, tubular dead cells. They are joined to each other by end to end forming a continuous pipe. The cells are thick and lignified.
- Xylem parenchyma: They are also called wood parenchyma. This is the only living tissue of xylem.
- Xylem fibre: They are dead cells with thick walled fibre.
- Phloem consists of sieve tubes, companion cells, phloem parenchyma and phloem fibres.
- Sieve tubes: These are elongated, tubular living cells arranged in a row, with their perforated end walls forming a sieve. They are non-nucleated. Their protoplasm are inter-connected through sieve plates. They possess vacuoles.
- Companion cell: They are elongated, lens-shaped cells containing dense cytoplasm and prominent nuclei. These cells maintain connection with sieve cells through pits.
- Phloem parenchyma: They are living thin walled parenchyma cells.
- Phloem fibre: They are also known as bast fibre. They are elongated fibre like sclerenchymatous dead cells with thick walls containing pits and interlocked ends. Phloem fibre are the only dead cells in phloem.
Hope you could get an idea from here.
Doubt clarification - use comment section.
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.
<span>I believe the answer is REM alpha sleep. Sleep is a complex biological process that accompany various physiological changes. Normal sleep is usually
classified into non-rapid movement (NRE) and rapid eye movement sleep (REM),
where the stages of NREM are followed by REM sleep. REM alpha sleep is a stage of REM that is associated with unique brain wave pattern such that during REM sleep a sleepers brain waves demonstrate characteristics similar to a walking sleep, a combination of alpha, beta and desynchronous waves.</span>
Answer:
a. Oxygen performs an essential role in the mentioned microbial cell in a manner that it takes part in the procedure of glycolysis, Krebs cycle, and electron transport chain, which eventually assists in the production of energy from food substrates and this generation of energy helps the cell to survive.
In the existence of oxygen, sugar gets dissociated through glycolysis to generate pyruvate, which again in the existence of oxygen is transformed into acetyl CoA. This moves into the Krebs cycle and gets dissociated to water and carbon dioxide generating ATP through ETC. This generation of ATP helps the cell to survive.
In low oxygen surrounding or in the absence of oxygen, some of the aerobic microbes can switch their respiratory pathway and carry on the process of fermentation and anaerobic respiration to produce energy and thrive. However, the mentioned microbial cell, which when it comes in contact with the low oxygen environment cannot carry out fermentation process and would die eventually.
b. This organism can be classified as obligate aerobes as they always need oxygen and do not possess the tendency to carry out the process of anaerobic respiration or fermentation under the absence of oxygenic environment.
