Types of Economic System

• Capitalist Economy- In a capitalist system, the products manufactured are divided among people not according to what people want but on the foundation of Purchasing Power—which is the ability to buy products and services. Which means an individual needs to have the money with him to buy the goods and services. The Low-cost housing for the underprivileged is much required but will not include as demand in the market because the needy do not have the buying power to back the demand. Therefore, the commodity will not be manufactured and provided as per market forces.
• Socialist Economy- This economy system acknowledges the three inquiries in a different way. In a socialist society, the government determines what products are to be manufactured in accordance with the requirements of society. It is believed that the government understands what is appropriate for the citizen of the country, therefore, the passions of individual buyers are not given much attention. The government concludes how products are to be created and how the product should be disposed of. In principle, sharing under socialism is assumed to be based on what an individual need and not what they can buy. A socialist system does not have a separate estate because everything is controlled by the government.
• Mixed Economic – Mixed systems have characteristics of both the command and market economic systems. For this purpose, the mixed economic systems are also called as dual economic systems. However, there is no sincere method to determine a mixed system. Sometimes, the word represents a market system beneath the strict administrative control in certain sections of the economy.

The three phases of the author's relationship with his grandmother before he left the country to study abroad are :-

• 1. CHILDHOOD = When he went to the village school and the grandmother helped him to get ready and went to school with him.
• 2. BOYHOOD = When he went to the city school in a bus he shared a room with his grandmother but she could not longer help him in his studies.
• 3. EARLY YOUTH = When he went to the university and was given a room of his own. The common link of friendship was snapped.

Stomata are small pores present in the epidermis of leaves. They regulate the process of transpiration and gaseous exchange. The stomatal pore is enclosed between two bean-shaped guard cells. The inner walls of guard cells are thick, while the outer walls are thin. The guard cells are surrounded by subsidiary cells. These are the specialised epidermal cells present around the guard cells. The pores, the guard cells, and the subsidiary cells together constitute the stomatal apparatus.

The xylem and phloem within a vascular bundles are arranged in an alternate manner on different radii is called radial vascular bundle. The xylem and phloem are situated at the same radius of the vascular bundles is called conjoint. 

1. Exarch: It is a type of primary xylem in which the protoxylem lies towards the periphery while the metaxylem lies towards the pith.
2. Endarch: It is a type of primary xylem in which the protoxylem lies towards the pith (centre) and the metaxylem lies towards the periphery of the organ.

Exarch xylem is the arrangement in which the protoxylem (the first formed primary xylem cells in a plant shoot/root) is directed towards the periphery and metaxylem (later formed primary xylem cells in a plant shoot/root) is directed towards the centre. Its development follows a centripetal pattern and is characteristics of roots. 

The first formed xylem elements are called protoxylem, while the later formed primary xylem is called metaxylem.

Protoxylem is the initially formed Xylem that develops before the plant organ is completely grown and Metaxylem is formed later.

The exterior portion of the cerebrum is called the cortex or the cerebral mantle. The cortex is extremely convoluted, due to which, it has a large surface area. 

let's look at the roles of a teacher. In short, a teacher teaches, but they also design the educational content to pass knowledge to students. Teachers are responsible for assessing students' learning and skills through testing or other assignments designed to illustrate the students' abilities. Through these assessments, teachers are often expected to identify at-risk students and bring those students to the attention of the proper departments within the school.

In short, a teacher is much more than a person who presents information.

Now, what is the role of a special education professional? A special education professional's roles include those of a traditional classroom teacher and of a support service provider. The difference between a special education professional and a mainstream teacher is that the special education professional performs all duties with and for students with varying degrees of disability and not all duties are related to teaching. All teachers must be aware of laws that regulate the education environment, but special education professionals must also be aware of the laws pertaining to people with disabilities. As we discuss special education professionals, we should first discuss their responsibilities to their students as vulnerable individuals.

The narrator’s uncle was considered to be a crazy man. Actually, he was the natural descendant of the crazy streak in the family. He was a huge and powerful man. He had a big strong head with black hair. He was a man of furious nature. He was short tempered and of irritable nature. He would not let anybody talk before him. He would stop him shouting. “It is no harm ; pay no attention to it.”

Stomatal apparatus is a pair of guard cells with or without surrounding subsidiary cells which function as a value to open or close a stomatal pore for gaseous exchange and transpiration. 

Each stoma is made of two bean-shaped cells called the guard cells. The guard cells are dumb-bell shaped in grasses. They contain chloroplasts and small vacuoles. They are thick-walled in the area of contact and thin-walled elsewhere. As the guard cells swell up due to endosmosis, their thin-walled sides expand. The thick walls of the two guard cells also bend outwardly and create a pore in between them.

Vascular bundles wherein xylem and phloem lie side by side are called as radial bundles while conjoint vascular bundles have xylem and phloem separated from one another as are found in leaves.
A conjoint vascular bundle can be collateral or bicollateral. Collateral vascular bundles have xylem and phloem arranged in same radium with xylem present towards the inner side and phloem towards the outer side. Bicollateral bundles have phloem on both sides of the xylem as compared to collateral bundles wherein phloem is present on one side of xylem only. In leaves, xylem is present near upper epidermis and phloem near the lower one with phloem on one side of xylem thus collateral, not bicollateral bundles. On the basis of the presence of absence of cambium, collateral bundles are grouped as open or close bundles, those with cambium are termed as open vascular bundles while the vascular bundles without cambium are termed as closed.
Leaves lack cambium in vascular bundles making them closed type, this vascular bundles in leaves are found irregularly scattered in the mesophyll with the largest and the oldest one at centre and is termed as midrib vein. Each vascular bundle has a bundle sheath of compactly arranged barrel shaped parenchyma cells which cover both xylem and phloem. Xylem is present near upper epidermis and phloem near the lower one. Xylem has protoxylem and metaxylem vessels with protoxylem present towards upper epidermis, thus conjoint, collateral close vascular bundle with endarch xylem. 

Simple permanent tissues are composed of cells which are structurally and functionally similar. They are of three types – parenchyma, collenchyma and sclerenchyma.

1. Parenchyma –

Parenchyma tissue consists of relatively unspecialised cells with thin cell walls. They are live cells. They are usually loosely packed, so that large spaces between them.  This tissue provides support to plants and also stores food. In some cases, it contains chlorophyll and performs photosynthesis, and then it is called as chlorenchyma. In aquatic plants, large air cavities are present in parenchyma to give buoyancy to the plants to help them float. Such a parenchyma type is called aerenchyma. The parenchyma of stems and roots also stores nutrients and water.

ii. Collenchyma –

The cells of collenchyma tissue are living, elongated and irregularly thickened at the corners. There is very little or no intercellular space. It allows easy bending in various parts of a plant (leaf, stem) without breaking. Thus, provides flexibility to the plant. It also provides mechanical support to plants.  

iii. Sclerenchyma –

The cells of sclerenchyma tissue are dead. They are long and narrow as the walls are thickened due to deposition of lignin. The walls of cells are so thick that there is no internal space inside the cell. This tissue is present in stems, around vascular bundles, in the veins of leaves and in the hard covering of seeds and nuts. It provides strength to the plant parts and makes the plant hard and stiff.

• Meristematic Tissue:

Meristematic tissues are growth tissues and found in the growing regions of the plant. According to their position in plant, meristems are apical, lateral and intercalary.

1. Apical meristem - Apical meristem is present at the growing tips of stems and roots and increases the length of the stem and the root.
2. Lateral meristem – Lateral meristems are found beneath the bark. The girth of the stem or root increases due to lateral meristem (cambium).
3. Intercalary meristem - Intercalary meristem is the meristem at the base of the leaves or internodes (on either side of the node) on twigs. It increases the length of the organs such as leaves and internodes.

Characteristics of Meristematic Tissues:

1. Their cells are similar in structure and have thin cellulose cell walls.
2. The cells are active and have dense cytoplasm.
3. They contain few vacuoles or no vacuoles at all.
4. The meristematic cells are compactly arranged and do not contain any intercellular space between them.

Complex permanent tissues –

Complex tissues are made of more than one type of cells. All these cells coordinate to perform a common function. Xylem and phloem are examples of such complex tissues. They are both conducting tissues and constitute a vascular bundle.

1. Xylem –

Xylem is a vascular and mechanical tissue. It consists of tracheids, vessels, xylem parenchyma and xylem fibres. Except xylem parenchyma, all xylem elements are dead and bounded by thick lignified walls. Tracheids and vessels are tubular structures which transports water and minerals vertically. The parenchyma stores food and helps in the sideways conduction of water. Fibres are mainly supportive in function.

ii. Phloem –

Phloem contains tubes but performs no mechanical function. Phloem is made up of four types of elements: sieve tubes, companion cells, phloem fibres and the phloem parenchyma. Sieve tubes are tubular cells with perforated walls. Phloem is unlike xylem in that materials can move in both directions in it. Phloem transports food from leaves to other parts of the plant. Except for phloem fibres, phloem cells are living cells.

Difference between Bar Diagram and Histogram:
(i) The spacing and the width or the area of bars are all arbitrary. It is the height and not the width or the area of the bar that really matters. But the width in a histogram is as important as its height.
(ii) Bar diagram can be drawn both for discrete and continous variables but histogram is drawn only for a continuous variables.
(iii) In bar diagram some space must be left between consecutive bars; but in histogram no space is, left between two rectangles.