The main purposes of roots are to stabilize the plant in the soil while also absorbing water and nutrients and absorb them from the soil and then begin to travel them up to disperse to the rest of the plant. Plants can also act as storage sites for food reserves. Water doesn't come to roots nearly as much as roots must come to water. Roots constantly have to grow to adapt to new water supplies. This constant need for water helps with the process of photosynthesis. Each plant has its own root system. These systems include either a taproots system or a fibrous root system.
A taproot system can be described as a large central root with numerous smaller lateral roots extending from that (ex: carrot). This large central root provides a strong anchor for the plant in the soil. Sometimes it is also used for food storage including a buildup of starch and water storage. The smaller, lateral roots serve as the main source to the central root for water and nutrients. Sections of this taproot system can create a new plant.
A fibrous root system consists of many roots that are all the same size; it has no predominant root. This root system has a large surface area to volume ratio (meaning that there is more area of the root touching the soil then there is actual volume of the root) making it effective in gathering nutrients. It also helps to anchor the plant and prevent soil erosion. Both of these systems have a threadlike extension (elongated cells) of their roots called root hairs.
The vascular bundles consist of the xylem and phloem and run throughout the plant as the transport system. They carry water to the leaves and carry sugar from photosynthesis throughout the plant. Vascular bundles refers to collections of tubes through which fluid materials move from one part of the plant to another.
Within a plant there are two main vascular tissues: the xylem and the phloem. The xylem is a principal vascular tissue within the plant. It transports water and helps to dissolves inorganic nutrients. The xylen is the tissue through which water and dissolved minierals flow in vascular plants. Xylem cells are stacked together to form a pipeline/tube throughout the plant from the root to the tips of all the leaves. The xylem is also involved in a process known as transpiration, serving as a tube to carry the water up the plant out the stomata. A xylem consists of vessel elements and tracheids which are two types of fluid conducting cells. These cells die off before the point of maturity. The tubes are essentially just strands of empty cells that have been cleared out. The walls of these cells are strengthened with cellulose and lignin that enables the load-bearing capacity.
Transpiration is the process that results once the water has evaporated from the plant and there is open space within the leaf. This space then creates a type of "suction" that is then filled by more water until it reaches the xylem. Once the water has reached the xylem the process of cohesion of hydrogen bonds between water molecules allows water to be transported, against gravity, up the plant. Also at work is the role of adhesion of the water molecules to the sides of the xylem helping with the transpiration stream of water.
The second main vascular tissue is called the phloem. Its primary purpose is in creating pressure flow. Phloem cells are laid out end to end in the plant to create a tube that transfers the product of photosynthesis (glucose or sugar) and some hormones throughout the plant. When photosynthesis occurs it creates sugar that is then loaded into the phloem, which then transports that sugar to the fruits, stems, and roots when it is stored. Phloem contains a sieve element who's job is to do the actual nutrient conducting. It doesn't die at maturity but it loses it's cell nucleus including all DNA. Every sieve element has an associating with a companion cell that retain its DNA and does all the housekeeping needs. The nucleus is removed to make extra space for the rapid flow of food through it.
All plant have chemical substances inside of them that bring about a certain response called hormones. Hormones serve as "chemical messengers" that originate in one part of the pant and then send a message to another part of the plant. Hormone production is a more diffuse process that in collections of cells carry out a range of different functions. There are five major hormones in plants, two of which called auxins and ethylene. Auxins are hormones that promote and regulate growth in the plant and the falling off of the leaves. They are also the hormone responsible for phototropism, or the growth of plants toward their light source. Also, auxins help differentiate between xylem and phloem tissue. Ethylene are hormones that are released by plants as a gas and affect the ripening of fruit and the promotion of the falling off of leaves. It is also responsible for slowing down of the lateral bud growth For example, if you were to place an unripe banana in a paper bag with a ripe banana the ethylene gas from the ripe banana would escape and spread to the unripe banana encouraging the production of more ethylene to create ripening. Ethylene initiates the reaction that converts the starches in plants to sugar, also known as the ripening of fruit.
Environmental factors that affect a plant are numerous. One such example is Photoperiodism which is the ability of plants to grow in accordance with the lengths of day and night. This process keys the plant on to important knowledge such as the length of day in accordance to the season. It could signal to the plant that it is time to start to produce buds or flowers and conversely if the days are shorter the plant knows to produce seeds for the winter season to allow for seasonal adaptation. (http://www.wisegeek.com/what-is-photoperiodism.htm). Another response to the environment is in response to sunlight. Phototropism is the bending, curvature and growth of plants according to its light source. This is because plants produce their own food and light is necessary for that production. Phototropism is the plant's response when sunlight becomes blocked by another plant or some other physical object. When the hormone auxin is redistributed in the plant according to the amount of light it is receiving, the plant bends toward more light in order to equalize the auxin throughout the plant. When light hits one side of the shoot, it causes auxin to move to the other side where it acts to lengthen the cells on the far side. This effects makes the shoot curve towards the light.
As the picture shows, the hormone auxin shifts to the dark side of the plant signaling to the cells to elongate themselves on a certain side of the plant. This process causes the bending of the plant toward the light source.
Another process of the plant responding to the environment is called photoperiodism.
Another response to the environment occurs through gravitropism which is the plants response to gravity; the fact that the roots desire to grow down toward the water and minerals that the plant needs, and the shoots want to grow upwards to access the sunlight. Roots have a positive gravitropic response because of they grow downwards. Shoots have a negative gravitropic response because they grow against gravity, upwards. This process is required in order for the plant to survive. For example, if a root's tip were to be snipped off then there would be no bending with regards to gravitropism, but instead a continuation of straight horizontal grows. It shows that cells or substances in the root cap are essential for root gravitorpism. Similarly to phototropism, the movement of the hormone auxin signifies the the plant a need to elongate some cells causing the plant to bend in a certain direction (http://www.microgravity.ac.uk/subjects/Plantgrav.htm).
The main purposes of roots are to stabilize the plant in the soil while also absorbing water and nutrients and absorb them from the soil and then begin to travel them up to disperse to the rest of the plant. Plants can also act as storage sites for food reserves. Water doesn't come to roots nearly as much as roots must come to water. Roots constantly have to grow to adapt to new water supplies. This constant need for water helps with the process of photosynthesis. Each plant has its own root system. These systems include either a taproots system or a fibrous root system.
A taproot system can be described as a large central root with numerous smaller lateral roots extending from that (ex: carrot). This large central root provides a strong anchor for the plant in the soil. Sometimes it is also used for food storage including a buildup of starch and water storage. The smaller, lateral roots serve as the main source to the central root for water and nutrients. Sections of this taproot system can create a new plant.
A fibrous root system consists of many roots that are all the same size; it has no predominant root. This root system has a large surface area to volume ratio (meaning that there is more area of the root touching the soil then there is actual volume of the root) making it effective in gathering nutrients. It also helps to anchor the plant and prevent soil erosion. Both of these systems have a threadlike extension (elongated cells) of their roots called root hairs.
The vascular bundles consist of the xylem and phloem and run throughout the plant as the transport system. They carry water to the leaves and carry sugar from photosynthesis throughout the plant. Vascular bundles refers to collections of tubes through which fluid materials move from one part of the plant to another.
Within a plant there are two main vascular tissues: the xylem and the phloem. The xylem is a principal vascular tissue within the plant. It transports water and helps to dissolves inorganic nutrients. The xylen is the tissue through which water and dissolved minierals flow in vascular plants. Xylem cells are stacked together to form a pipeline/tube throughout the plant from the root to the tips of all the leaves. The xylem is also involved in a process known as transpiration, serving as a tube to carry the water up the plant out the stomata. A xylem consists of vessel elements and tracheids which are two types of fluid conducting cells. These cells die off before the point of maturity. The tubes are essentially just strands of empty cells that have been cleared out. The walls of these cells are strengthened with cellulose and lignin that enables the load-bearing capacity.
Transpiration is the process that results once the water has evaporated from the plant and there is open space within the leaf. This space then creates a type of "suction" that is then filled by more water until it reaches the xylem. Once the water has reached the xylem the process of cohesion of hydrogen bonds between water molecules allows water to be transported, against gravity, up the plant. Also at work is the role of adhesion of the water molecules to the sides of the xylem helping with the transpiration stream of water.
The second main vascular tissue is called the phloem. Its primary purpose is in creating pressure flow. Phloem cells are laid out end to end in the plant to create a tube that transfers the product of photosynthesis (glucose or sugar) and some hormones throughout the plant. When photosynthesis occurs it creates sugar that is then loaded into the phloem, which then transports that sugar to the fruits, stems, and roots when it is stored. Phloem contains a sieve element who's job is to do the actual nutrient conducting. It doesn't die at maturity but it loses it's cell nucleus including all DNA. Every sieve element has an associating with a companion cell that retain its DNA and does all the housekeeping needs. The nucleus is removed to make extra space for the rapid flow of food through it.
Environmental System
All plant have chemical substances inside of them that bring about a certain response called hormones. Hormones serve as "chemical messengers" that originate in one part of the pant and then send a message to another part of the plant. Hormone production is a more diffuse process that in collections of cells carry out a range of different functions. There are five major hormones in plants, two of which called auxins and ethylene. Auxins are hormones that promote and regulate growth in the plant and the falling off of the leaves. They are also the hormone responsible for phototropism, or the growth of plants toward their light source. Also, auxins help differentiate between xylem and phloem tissue. Ethylene are hormones that are released by plants as a gas and affect the ripening of fruit and the promotion of the falling off of leaves. It is also responsible for slowing down of the lateral bud growth For example, if you were to place an unripe banana in a paper bag with a ripe banana the ethylene gas from the ripe banana would escape and spread to the unripe banana encouraging the production of more ethylene to create ripening. Ethylene initiates the reaction that converts the starches in plants to sugar, also known as the ripening of fruit.
Environmental factors that affect a plant are numerous. One such example is Photoperiodism which is the ability of plants to grow in accordance with the lengths of day and night. This process keys the plant on to important knowledge such as the length of day in accordance to the season. It could signal to the plant that it is time to start to produce buds or flowers and conversely if the days are shorter the plant knows to produce seeds for the winter season to allow for seasonal adaptation. (http://www.wisegeek.com/what-is-photoperiodism.htm). Another response to the environment is in response to sunlight. Phototropism is the bending, curvature and growth of plants according to its light source. This is because plants produce their own food and light is necessary for that production. Phototropism is the plant's response when sunlight becomes blocked by another plant or some other physical object. When the hormone auxin is redistributed in the plant according to the amount of light it is receiving, the plant bends toward more light in order to equalize the auxin throughout the plant. When light hits one side of the shoot, it causes auxin to move to the other side where it acts to lengthen the cells on the far side. This effects makes the shoot curve towards the light.
As the picture shows, the hormone auxin shifts to the dark side of the plant signaling to the cells to elongate themselves on a certain side of the plant. This process causes the bending of the plant toward the light source.
Another process of the plant responding to the environment is called photoperiodism.
Another response to the environment occurs through gravitropism which is the plants response to gravity; the fact that the roots desire to grow down toward the water and minerals that the plant needs, and the shoots want to grow upwards to access the sunlight. Roots have a positive gravitropic response because of they grow downwards. Shoots have a negative gravitropic response because they grow against gravity, upwards. This process is required in order for the plant to survive. For example, if a root's tip were to be snipped off then there would be no bending with regards to gravitropism, but instead a continuation of straight horizontal grows. It shows that cells or substances in the root cap are essential for root gravitorpism. Similarly to phototropism, the movement of the hormone auxin signifies the the plant a need to elongate some cells causing the plant to bend in a certain direction (http://www.microgravity.ac.uk/subjects/Plantgrav.htm).