Heavy metal refers to metals and metalloids that are toxic to both plants and animals even at a very low concentration. Some of these heavy metals do not perform any known physiological function in plants, such as As, Cd, Hg, Pb or Se, these are non essential metals. Others, such as Co, Cu, Fe, Mn, Mo, Ni and Zn, are essential elements required for normal growth and metabolism of plants. Essential elements can lead to poisoning when their concentration rises to beyond optimal levels [1]. Human activities, such as mining, industrial and domestic waste water and sludge, fertilizers and pesticides application to field, also atmospheric deposition are the main sources of heavy metal contamination in plants [2].
Metal contamination of agricultural
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However, further investigation on how essential and non- essential metal ions affect plant growth at different stages of development under varying environmental conditions have to be done. Seed is a stage in the plant life cycle that is well protected against various kinds of stress. However, after imbibition and during vegetative developmental processes, they become stress sensitive. Therefore seed carefully monitors external conditions such as light, temperature and nutrient in order to maintain the protective state until conditions become favourable for further developmental processes …show more content…
Plants absorb heavy metals from the subsurface of 25cm depth zone of the soil where roots of most cereal crops are located [16]. After the soil is saturated with heavy metals, more of it would be distributed in the aqueous phase and the availability of the heavy metals to plants would subsequently be increased [17]. High concentration of heavy metals in soil will increase the potential of being taken up by plants [18].
Plasma membrane of root cells is the first barrier for heavy metals entering the symplasm, any interaction of ions with the plasma membrane like negative and/or toxic effect should be first studied at the level of the plasma membrane. Metal ion toxicity on the plasma membrane is indicated via disturbed membrane functionality, lipid peroxidation and subsequent ion imbalance in the cytoplasm due to loss of ions, such as K+. Such disturbances in the plasma membrane function induce an imbalanced ion influx/efflux ratio resulting in a change in the membrane potential
Hypothesis: If one-day pinto bean seedlings are soaked in a water solution, 1% NaCl solution, and 3% NaCl solution, the seedlings exposed to higher sodium concentrations will have decreased cellular respiration rates. Treatments: This experiment involved three treatments and a control. The goal of the experiment was to see how different levels of NaCl affect the rates of cellular respiration in day-old pinto bean seedlings.
According to the article “How Tap Water Became Toxic in Flint, Michigan,” written by Sara Ganim and Linh Tran, the residents of Flint, Michigan highly disapproved of the new water source. Around 2 years ago, the city of Flint was forced to switch their water supply from Lake Huron to a more local source, Flint River. Before, this was not a big problem to the residents of Flint because they were told that the water they were drinking was harmless. However, people began to doubt that the water they were drinking was safe because it looked like sewage. Over time, new evidence began to arise claiming that the water contained massive amounts of lead and iron.
If the experiment was completed again, more higher concentrations could be applied to the seeds to see if the data is further supported. Either way the more trials the better and more accurate results, this applies to any experiment. Practical applications of the principles of this investigation may be using the correct concentration for a specific plant or seed. This lab shows that it is necessary to follow the directions and specifications when using the fertilizer miracle
Cell Respiration Lab Research Question What is the optimal temperature for germinating pea-seeds where the rate of respiration is the greatest? Background Information Cell Respiration refers to the biochemical process conducted by the cells of an organism that combines glucose and oxygen to produce energy in the form of ATP, along with two by-products, water and carbon dioxide. The equation representing this chemical reaction is shown below. C6H12O6 + 6 O2 6 CO2 + 6 H2O
These were shown to display spikes of activity of EPSPs. The spikes in cell 2 match up with the sub-threshold activity in cell 1. This was expected. When cell 2 reaches an action potential with its amplitude at 12mV, in figure 4, has a knock on effect of slightly hyperpolarising the following spike in cell 1. This hyperpolarisation is due to the fact that cell 1 and cell 2 are linked and so a depolarisation in cell 2 will lead to a small hyperpolarisation in cell 1.
RESTING MEMBRANE POTENTIAL When the neuron is not sending a signal at rest the membrane potential called as resting membrane potential. In this stage, permeability of K+ much greater than Na+ When a neuron is at rest, the inside of the neuron is negative relative to the outside. Although the concentrations of the different ions endeavor to balance out on both sides of the membrane, they cannot because the cell membrane sanctions only some ions to pass through channels (ion channels). At rest, potassium ions (K+) can cross through the membrane facilely. Additionally at rest, chloride ions (Cl-) and sodium ions (Na+) have a more arduous time crossing.
This allows sodium ions to flood into the cell at that location the membrane there is ‘depolarized’, with the inside of the cell having a net positive charge and the outside having a net negative charge. This affects neighboring sodium channels, which then open moving the depolarization along the membrane. This is called action potential. Changes occur behind the action potential to restore the resting membrane potential. The sodium channels close and the potassium channels open.
Thus the gradients push potassium ions out of the axon, helping the membrane potential go back to its value at rest. As the resting potential goes back to its original value, it is temporarily hyperpolarized due to the potassium ions just leaving and causing the charge between the inside and outside to differ more than resting potential (the inside is seemingly more negative in comparison to the outside).The resting potential is restored after the potassium ions diffuse away, even though the distributions of Na+ and K+ differ from what they were before the process. This is where the sodium-potassium pump comes back to reestablish the concentrations of the ions before the action
A change in Na+ or K+ conductance would affect the resting membrane potential by changing the difference
Arsenic comes in several forms which are potentially poisonous. Many water supplies which are located near mines have a higher risk of being contaminated by arsenic poisons. Arsenic can disrupt the metabolic levels in the human body. Lead is another chemical which is a great concern to the human health. Although lead is a natural element in the environment, most of the pollutants of lead come from human activities.
This lets us to notice what in the red blood cell was able to permeable across the cell membrane, since they were placed in different osmolality solutions we are able observe the tonicity of the cell’s behavior. When the Erythrocyte is placed into a hypotonic solution, the cell will swell because water will move gradually into the cell. The concentration of solutes are lower outside than the inside of the cell, so the water will move in the cell and cause the cell to swell. If the cell was placed to hypertonic solution, the solution has a higher solute concentration than the cell, so the water moves out the cell and causes the cell to shrink. When the red blood cell is placed into a isotonic solution, the concentration of the
Introduction: In this task I will be researching the effect that acid rain has on the rate of plant growth. Acid rain is any type of precipitation with a high pH, with high levels of nitric acids. The reason why I had chosen this topic was because acid rain seems to have a great effect on the effect of plant growth, and plants play a very important role in our ecosystem. Acid rain is a major problem in our environment when we are not able to neutralize the acidity.
In some areas, soils contain enough calcium ions (Ca2+) and magnesium ions (Mg+2) that are attached to the negatively charged minerals in the soil to neutralise or buffer
This means there is no movement of ions in or out of the cell membrane and a resting potential is attained. At this point, there are more sodium ions outside the cell membrane and more potassium ions inside the
Introduction Plants are a major necessity in the balance of nature, people’s lives, and our terrain. We may not realize it, but plants are the ultimate source of food for almost 95% of the world population so says the National Group of Food. It’s a fact that over 7,000 species of plants are being consumed today. Plants are one of the reasons that we get clean water; as they help regulate the water cycle.