0
What else can I help you with?
What are the primary meristems?
they are... 1.Protoderm 2.Procambium 3.Ground meristem
What three kinds of tissues does meristematic develop into?
The three kinds of tissues that meristematic tissue develops into are protoderm, procambium, and ground meristem. All three are responsible for an increase in height and length.
What three kinds of tissues does meristematic tissue develop into?
Meristematic tissue develops into epidermal tissue, vascular tissue, and ground tissue. Epidermal tissue forms the outer layer of the plant, vascular tissue conducts water and nutrients, and ground tissue provides support and storage.
What do Apical Meristems produce?
Apical meristems produce new primary growth in plants, including new leaves, stems, and branches. They are responsible for the upward growth of the plant and play a key role in its development and overall structure.
What makes new xylem and phloem?
The new xylem is produced by the division and differentiation of cells in the vascular cambium layer, while new phloem is produced by the division and differentiation of cells in the vascular cambium or the procambium during secondary growth in plants. These cells differentiate into xylem vessels, fibers, and phloem sieve tubes, companion cells, and fibers respectively.
What is the dermal tissue ground tissue and vascular tissue systems are derived from?
According to the theory of Tunica-corpus, the dermal tissue is derived from tunica and the rest of the tissues namely ground tissue and vascular tissue systems are derived from the corpus. This theory has been accepted by a large number of botanists.
What is the common name for secondary xylem?
primary xylem is primary in nature & is derived from procambium. But secondary xylem is secondary in nature and derived from fascicular cambium and interfascicular cambium. Primary xylem is differentiated into protoxylem and metaxylem, but secondary xylem has no such differentiation. In primary xylem vessels and tracheids are long and narrow, and vessels don't have tyloses, but in secondary xylem, vessels are blocked by tyloses, and vessels and tracheids are wider and shorter. Xylem fibres are more abundant in secondary xylem , and found in small numbers in primary xylem. Also unlike in primary xylem, secondary xylem has differentiated into sapwood & heartwood.
What is the function of a pith of a tree?
The pith of the tree is formed from the procambium, usually during the first year of growth. The heartwood is not a storage area for "impurities". The heartwood is between the pith and the sapwood. It acts as mechanical support for the tree and contains "extractives" (not impurities) that evolve, over eons, to protect the tree from disease, insects, fungi, fire, and other environmental competitors.Pith isn't even considered as wood. It's usually a spongy type of material consisting of parenchymous cells. Heartwood is "dead" and the sapwood, cambium, and inner bark (phloem...HEY, that's my username!) are living tissues (contain cytoplasm)
Difference between primary and secondary phloem?
Primary phloem 1. . Derived from procambium of apical meristem. 2. . District protophloem and metaphloem elements.3 Sieve tubes long and narrow. 3. Less or no development of phloem parenchyma. 4. Phloem fibres on the outer part. Secondary phloem 1. . Derived from vascular cambium. 2. . No clear demarcation between protophloems and metaphloems. 3. Sieve tubes short and wide. 4. .Well developed and abundant phloem parenchyma. 5. . Phloem fibers among the phloem parenchyma.
How tree rings formed?
EASY EXPLANATION Trees form rings (also known as annual growth rings) because in temperate regions the vascular cambium, a type of lateral meristem that causes growth of secondary xylem, becomes dormant during the winter and later resumes growth in the spring. Because the cells are much smaller right before dormancy compared to the large cells right after dormancy, there is a clear difference, or ring, that is visible. This process occurs periodically every winter (every year), resulting in annual growth rings.SLIGHTLY LESS EASY EXPLANATIONVascular tissues of plants are of two types1. Xylem2. PhloemAnd these 2 tissues are again of 2 types1. Primary2. SecondaryThe primary vascular tissues are present in all vascular plants and are formed from a primary meristem called PROCAMBIUM . The secondary vascular tissues are found only in dicot plants because they develop from a special kind of meristem ( lateral ) called VASCULAR CAMBIUM which is seen only in dicots. The production of secondary vascular tissues is called SECONDARY GROWTH.The vascular cambium produces secondary xylem to its inner side and secondary phloem to its outer side.During spring, there is more activity in the plant due to the formation of new leaves, etc, hence the increased need for more water supply and thus more secondary xylem with large lumen is produced. This wood appears light in colour and is called EARLY WOOD or SPRING WOOD.During autumn all the leaves fall off and there is not much need of xylem and hence the activity of vascular cambium decreases and less xylem with narrow lumen are produced. This wood appears dark and is called LATE WOOD or AUTUMN WOOD.Thus every year two types of wood are formed which appear as a ring called ANNUAL RING or GROWTH RING.
What does the phloem cell do?
The phloem originates, and grows outwards from, meristematic cells in the vascular cambium. Phloem is produced in phases. Primary phloem is laid down by the apical meristem and develops from the procambium. Secondary phloem is laid down by the vascular cambium to the inside of the established layer(s) of phloem. In some eudicot families (Apocynaceae, Convolvulaceae, Cucurbitaceae, Solanaceae, Myrtaceae, Asteraceae), phloem also develops on the inner side of the vascular cambium; in this case a distinction between external phloem and internal phloem or intraxylary phloem is made. Internal phloem is mostly primary, and begins differentiation later than the external phloem and protoxylem, though it's not without exceptions. In some other families (Amaranthaceae, Nyctaginaceae, Salvadoraceae) the cambium also periodically forms inward strands or layers of phloem, embedded in the xylem: such phloem strands are called included phloem or interxylary phloem The Pressure flow hypothesis was a hypothesis proposed by Ernst Munch in 1930 that explained the mechanism of phloem translocation. A high concentration of organic substance inside cells of the phloem at a source, such as a leaf, creates a diffusion gradient that draws water into the cells. Movement occurs by bulk flow; phloem sap moves from sugar sources to sugar sinks by means of turgor pressure gradient. A sugar source is any part of the plant that is producing or releasing sugar. During the plant's growth period, usually during the spring, storage organs such as the roots are sugar sources, and the plant's many growing areas are sugar sinks. The movement in phloem is multidirectional, whereas, in xylem cells, it is unidirectional (upward). After the growth period, when the meristems are dormant, the leaves are sources, and storage organs are sinks. Developing seed-bearing organs (such as fruit) are always sinks. Because of this multi-directional flow, coupled with the fact that sap cannot move with ease between adjacent sieve-tubes, it is not unusual for sap in adjacent sieve-tubes to be flowing in opposite directions. While movement of water and minerals through the xylem is driven by negative pressures (tension) most of the time, movement through the phloem is driven by positive hydrostatic pressures. This process is termed translocation, and is accomplished by a process called phloem loading and unloading. Cells in a sugar source "load" a sieve-tube element by actively transporting solute molecules into it. This causes water to move into the sieve-tube element by osmosis, creating pressure that pushes the sap down the tube. In sugar sinks, cells actively transport solutes out of the sieve-tube elements, producing the exactly opposite effect. Some plants however appear not to load phloem by active transport. In these cases a mechanism known as the polymer trap mechanism was proposed by Robert Turgeon. In this case small sugars such as sucrose move into intermediary cells through narrow plasmodesmata, where they are polymerised to raffinose and other larger oligosaccharides. Now they are unable to move back, but can proceed through wider plasmodesmata into the sieve tube element. The symplastic phloem loading (polymer trap mechanism above) is confined mostly to plants in tropical rain forests and is seen as more primitive. The actively-transported apoplastic phloem loading is viewed as more advanced, as it is found in the later-evolved plants, and particularly in those in temperate and arid conditions. This mechanism may therefore have allowed plants to colonise the cooler locations. Organic molecules such as sugars, amino acids, certain hormones, and even messenger RNAs are transported in the phloem through sieve tube elements.
What is some of the characteristics of Phylum Coniferophyta?
Phylum Coniferophyta includes plants like pine trees, spruce, and fir. They have needle-like or scale-like leaves, produce cones for reproduction, and are typically evergreen. Conifers are adapted to colder climates and tend to have a conical shape to shed snow easily.
