Write characteristics and Classification.

Question:

Write characteristics and Classification. 

Answer:

Characteristics of Fungi

Following are the important characteristics of fungi:

1. Fungi are eukaryotic, non-vascular, non-motile and heterotrophic organisms.
2. They may be unicellular or filamentous.
3. They reproduce by means of spores.
4. Fungi exhibit the phenomenon of alternation of generation.
5. Fungi lack chlorophyll and hence cannot perform photosynthesis.
6. Fungi store their food in the form of starch.
7. Biosynthesis of chitin occurs in fungi.
8. The nuclei of the fungi are very small.
9. The fungi have no embryonic stage. They develop from the spores.
10. The mode of reproduction is sexual or asexual.
11. Some fungi are parasitic and can infect the host.
12. Fungi produce a chemical called pheromone which leads to sexual reproduction in fungi.
13. Examples include mushrooms, moulds, yeast.

Classification of Fungi

Kingdom Fungi are classified based on different modes. The different classification of fungi is as follows:

Based on Mode of nutrition

On the basis of nutrition, kingdom fungi can be classified into 3  groups.

1. Saprophytic – The fungi obtain their nutrition by feeding on dead organic substances. Examples: Rhizopus, Penicillium and Aspergillus.
2. Parasitic – The fungi obtain their nutrition by living on other living organisms (plants or animals) and absorb nutrients from their host. Examples: Taphrina and Puccinia.
3. Symbiotic – These fungi live by having an interdependent relationship association with other species in which both are mutually benefited. Examples: Lichens and mycorrhiza. Lichens are the symbiotic association between algae and fungi. Here both algae and fungi are mutually benefited as fungi provide shelter for algae and in reverse algae synthesis carbohydrates for fungi.

Based on Spore Formation

Kingdom Fungi are classified into the following based on the formation of spores:

1. Zygomycetes – These are formed by the fusion of two different cells. The sexual spores are known as zygospores while the asexual spores are known as sporangiospores. The hyphae are without the septa.
2. Ascomycetes – They are also called as sac fungi. They can be coprophilous, decomposers, parasitic or saprophytic. The sexual spores are called ascospores. Asexual reproduction occurs by conidiospores. Example – Saccharomyces
3. Basidiomycetes – Mushrooms are the most commonly found basidiomycetes and mostly live as parasites. Sexual reproduction occurs by basidiospores. Asexual reproduction occurs by conidia, budding or fragmentation. Example- Agaricus
4. Deuteromycetes – They are otherwise called imperfect fungi as they do not follow the regular reproduction cycle as the other fungi. They do not reproduce sexually. Asexual reproduction occurs by conidia. Example – Trichoderma.

Write Law of Dominance Segregation.

Question:

Write Law of  Dominance Segregation.

Inheritance is the acquiring of genetic characteristics or traits from parents by their offspring.

In the year 1860, Gregor Johann  Mendel, the father and founder of genetics unlocked the mystery of genetics. He conducted many experiments on the pea plants and observed their pattern of inheritance from one generation to the next generation. His investigation led to the discovery of three laws of inheritance, famously known as Mendel’s Laws of Inheritance.

The Law of Dominance, Law of Segregation and Law of Independent Assortment are the three Mendel’s laws of inheritance. These laws came into existence by the experiments on pea plants in a variety of differing traits. Mendel started his research with monohybrid cross.

Mendel observed that traits which were absent in the F1 generation had reappeared in the F2 generation. These observations led to the formulation of the Law of Dominance and the Law of Segregation.

Law of Dominance:

Mendel’s law of dominance states that:

“When parents with pure, contrasting traits are crossed together, only one form of trait appears in the next generation. The hybrid off springs will exhibit only the dominant trait in the phenotype.”

Law of dominance is known as the first law of inheritance. In this law, each character is controlled by distinct units called factors, which occur in pairs. If the pairs are heterozygous, one will always dominate the other.

Law of dominance explains that in a monohybrid cross between a pair of contrasting traits, only one parental character will be expressed in the F1 generation and both parental characters will be expressed in the F2 generation in the ratio 3:1.

The one which is expressed in the F1 generation is called the dominant trait and the one which is suppressed is called a recessive trait. In simple words, the law of dominance states that recessive traits are always dominated or masked by the dominant trait. This law can be described by Mendel’s experiment.

A monohybrid cross is a cross between the two monohybrid traits (TT and tt). Here plants which have the same characters, but differ in only one character were crossed.

For monohybrid cross, Mendel began with a pair of pea plants with two contrasting traits, i.e., one tall and another dwarf. The cross-pollination of tall and dwarf plants resulted in tall plants and the offspring were called F1 progeny. The trait which is expressed in the phenotype is called the dominant trait while the one that is not is called the recessive trait.

He then continued his experiment with self-pollination of F1 progeny plants. This resulted in both tall and short plants in the ratio of 3:1 which gave rise to the law of segregation.

Law of Segregation:

Mendel’s law of segregation states that:

“During the formation of gamete, each gene separates from each other so that each gamete carries only one allele for each gene.”

Law of segregation is the second law of inheritance. This law explains that the pair of alleles segregate from each other during meiosis cell division (gamete formation) so that only one allele will be present in each gamete.

In a monohybrid cross, both the alleles are expressed in the F2 generation without any blending. Thus, the law of segregation is based on the fact that each gamete contains only one allele.

This law is based on four basic concepts:

• A gene exists in more than one form of an allele.
• When gametes are produced by meiosis, the allelic pairs separate, leaving each gamete with a single allele.
• Every organism inherits two alleles for each trait.
• The two alleles of a pair are different, i.e., one is dominant and one is recessive.

 

Write Functions of RNA and write type of RNA.

Question:

Write Functions of RNA and write type of RNA.

Answer:

Functions of RNA

The ribonucleic acid – RNA, which are mainly composed of nucleic acids, are involved in a variety of functions within the cell and are found in all living organisms including bacteria, viruses, plants, and animals. These nucleic acid functions as a structural molecule in cell organelles and are also involved in the catalysis of biochemical reactions. The different types of RNA are involved in various cellular process. The primary functions of RNA:

• Facilitate the translation of DNA into proteins
• Functions as an adapter molecule in  protein synthesis
• Serves as a messenger between the DNA and the ribosomes.
• They are the carrier of genetic information in all living cells
• Promotes the ribosomes to choose the right amino acid which is required in building up of new proteins in the body.

Also Read: Difference between deoxyribose and ribose

RNA Types

There are various types of RNA, out which most well-known and most commonly studied in the human body are :

• tRNA – Transfer RNA

The transfer RNA is held responsible for choosing the correct protein or the amino acids required by the body in-turn helping the ribosomes. It is located at the endpoints of each amino acid. This is also called as soluble RNA and it forms a link between the messenger RNA and the amino acid.

• rRNA-Ribosomal RNA

The rRNA is the component of the ribosome and are located within the in the cytoplasm of a cell, where ribosomes are found. In all living cells, the ribosomal RNA plays a fundamental role in the synthesis and translation of mRNA into proteins. The rRNA is mainly composed of cellular RNA and are the most predominant RNA within the cells of all living beings.

• mRNA – Messenger RNA.

This type of RNA functions by transferring the genetic material into the ribosomes and pass the instructions about the type of proteins, required by the body cells. Based on the functions, these types of RNA is called the messenger RNA. Therefore, the mRNA plays a vital role in the process of transcription or during the protein synthesis process.

What is Irrigation? also write type of irrigation.

Question:

What is Irrigation? also write type of irrigation.

Answer:

What is Irrigation?

Irrigation is the process of applying water to the crops artificially to fulfil their water requirements. Nutrients may also be provided to the crops through irrigation. The various sources of water for irrigation are wells, ponds, lakes, canals, tube-wells and even dams. Irrigation offers moisture required for growth and development, germination and other related functions.

The frequency, rate, amount and time of irrigation are different for different crops and also vary according to the types of soil and seasons. For example, summer crops require a higher amount of water as compared to winter crops.

Let us have a look at different types of irrigation and the methods used for irrigation.

Types of Irrigation

There are different types of irrigation practiced for improving crop yield. These types of irrigation systems are practiced based on the different types of soils, climates, crops and resources. The main types of irrigation followed by farmers include:

Surface Irrigation

In this system, no irrigation pump is involved. Here, water is distributed across the land by gravity.

Localized Irrigation

In this system, water is applied to each plant through a network of pipes under low pressure.

Sprinkler Irrigation

Water is distributed from a central location by overhead high-pressure sprinklers or from sprinklers from the moving platform.

Drip Irrigation

In this type, drops of water are delivered near the roots of the plants. This type of irrigation is rarely used as it requires more maintenance.

Centre Pivot Irrigation

In this, the water is distributed by a sprinkler system moving in a circular pattern.

Sub Irrigation

Water is distributed through a system of pumping stations gates, ditches and canals by raising the water table.

Manual Irrigation

This a labour intensive and time-consuming system of irrigation. Here, the water is distributed through watering cans by manual labour.

Write Traditional Methods of Irrigation.

Question:

Write Traditional Methods of Irrigation.

Answer:

Traditional methods of irrigation are the oldest method used in the earlier years., which are more affordable, efficient than the modern methods.  Some of these methods of irrigation are still followed today.

The traditional methods of irrigation include the following:

• Check Basin Method
• Furrow Irrigation Method
• Strip Irrigation Method
• Basin Irrigation Method

Check Basin Method

It is one of the best methods of irrigation for levelled fields. The field is divided into basins according to the water capacity. A small drain connects the basin. The basin size is as per the water inflow. The topmost place in the field is the main source of water.

This method does not require any technique. Also, it is rather inexpensive. It prevents soil erosion as the rainwater stays in the basin. A large area can be efficiently irrigated by this method.

Furrow Irrigation

Furrow irrigation is very prominent in crops planted in rows. ‘Dol’ (meaning: to sprout) is formed along the sides of the rows and the water flows between two ‘Dols’.

If the furrow is filled, there is no need to provide water again. It is comparatively cheap but is labour-intensive. Food crops planted in large areas get a huge amount of water by this method.

Strip Irrigation

The fields are divided into strips of different sizes. The strips are constructed according to the slope. The structure of the land determines the size of the strips. It is an easy irrigation method and requires less labour.

Write importance of irrigation.

Question:

Write importance of irrigation.

Answer:

Importance of Irrigation

The importance of irrigation can be explained in the following points:

1. Insufficient and uncertain rainfall adversely affects agriculture. Droughts and famines are caused due to low rainfall. Irrigation helps to increase productivity even in low rainfall.
2. The productivity on irrigated land is higher as compared to the un-irrigated land.
3. Multiple cropping is not possible in India because the rainy season is specific in most of the regions. However, the climate supports cultivation throughout the year. Irrigation facilities make it possible to grow more than one crop in most of the areas of the country.
4. Irrigation has helped to bring most of the fallow land under cultivation.
5. Irrigation has stabilized the output and yield levels.
6. Irrigation increases the availability of water supply, which in turn increases the income of the farmers.

Irrigation should be optimum because even over-irrigation can spoil the crop production. Excess water leads to waterlogging, hinder germination, increased salt concentration and uprooting because roots can’t withstand standing water. Thus the proper method is to be used for the best cultivation.

Write three basic characteristics of a modern landfill site. What are the reasons they are used?

Question:

Write three basic characteristics of a modern landfill site. What are the reasons they are used?

Answer:

Following are the characteristics:

• Compaction and integument of the waste to prevent it from being blown by the wind

• Procedures to contain leachates such as lining clay or plastic liners

• To extract gas to use in the generation of power, landfills gas extraction systems are installed.

The following are the reasons why their use must be promoted:

• Through recycling and recovery of waste, they trigger the waste prevention

• A uniform cost for the disposal of waste is created which subsequently will prevent the essential transport of waste.

• They help in bringing down negative effects on the environment and risk to human health that emerges from the landfilling of wastes.