Kerala PSC KAS Prelims Paper 2 Mock Test - 9 - Kerala PSC KAS MCQ

• A proportional tax is an income tax system that levies the same percentage tax to everyone regardless of income. A proportional tax is the same for low, middle, and high-income taxpayers. Proportional taxes are sometimes referred to as flat taxes. Proportional taxation is intended to create greater equality between marginal tax rates and average tax rates paid. Hence statement 1 is not correct. 
• Proportional taxes reduce the autonomous expenditure multiplier because taxes reduce the marginal propensity to consume out of income. The proportional income tax acts as an automatic stabilizer – a shock absorber because it makes disposable income, and thus consumer spending, less sensitive to fluctuations in GDP as compared to progressive taxation. Hence statement 2 is not correct. 
  • Progressive tax is the one where the tax rate increases with the taxpayer’s income. An example for progressive taxation is: 10% tax rate for income of Rs 2 lakh, 20% for Rs 5 lakh and 30% for Rs 10 lakh. Here, the tax liability or the absolute amount as well as the proportion of income to be paid as tax increases with the income of the taxpayer.

In News: Seven products from across India including four from Rajasthan were given the Geographical Indication (GI) tag by the Geographical Indications Registry in Chennai. Statements 1 and 2 are correct : Geographical Indication (GI) is a sign used on products that have a specific geographical origin and possess qualities or a reputation that are due to that origin. 

• In order to function as a GI, a sign must identify a product as originating in a given place. 
• Geographical Indications are covered as a component of intellectual property rights (IPRs) under the Paris Convention for the Protection of Industrial Property. 
• At the International level, GI is governed by the World Trade Organisation’s (WTO’s) Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS). 
• In India, Geographical Indications registration is administered by the Geographical Indications of Goods (Registration and Protection) Act, 1999 which came into force with effect from September 2003. 
• Statement 3 is not correct : The first product in India to be accorded with GI tag was Darjeeling tea in the year 2004-05.

‘Mahatma Gandhi National Rural Employment Guarantee Act, 2005' is a poverty alleviation programme of the Government of India, which provides the legal Right to Work in exchange for money to the citizens of the country. 

• Statement 1 is not correct: It aims to enhance livelihood security in rural areas by providing at least 100 days of guaranteed wage employment in a financial year to every household whose adult members volunteer to do unskilled manual work.
• Statement 2 is correct: According to the MGNREGA, there should be one ombudsperson per district, responsible for registering suo-moto complaints and disposing of them within 30 days.
• It has directed State governments to provide the facility to ombudspersons

India’s DPI experiment - “India Stack”: 

• The remarkable transformation of India’s digital landscape has been made possible by pioneering digital public infrastructure (DPI) experiments.
• The Indian DPI ecosystem envisioned as “India Stack” has been pivotal in unlocking the power of identity, payments, and data sharing to drive economic growth and foster a more inclusive digital economy. 
• Its transformative ability lies in 
  • Its potential to be used across multiple use cases, 
  • Enabling the creation of novel solutions that drive innovation, 
  • Inclusion and competition in the digital realm through its modular layers.

Statement 1 is not correct: Coastal aquaculture includes the farming of marine life such as shrimp, prawn or fish in controlled conditions. It is carried out in saline and brackish water. Statement 2 is correct: The Bill amends the Coastal Aquaculture Authority Act, 2005. 

• The Act defines coastal aquaculture as farming, under controlled conditions, of: (i) shrimp, (ii) prawn, (iii) fish or (iv) any other aquatic life in saline or brackish water.
• The Bill expands the scope of coastal aquaculture to include allied activities such as hatcheries and nucleus breeding centres.
• It also decriminalises certain offences under it to promote the ease of doing business. Statement 3 is not correct: Penalties: The 2005 Act penalises unregistered farms or farms in prohibited areas, with imprisonment up to three years and/or a fine of one lakh rupees.

The Bill replaces this and specifies that if coastal aquaculture is carried out illegally:

(i) the activity may be suspended,
(ii) structure may be removed,
(iii) crop may be destroyed,
(iv) the registration may be cancelled, and/or
(v) a penalty may be imposed

Both the Statements are correct.
What is Deflation?

• Deflation is a general decline in prices for goods and services, typically associated with a contraction in the supply of money and credit in the economy. 
• During deflation, the purchasing power of currency rises over time. Impact of Deflation 
• Deflation benefits consumers because they can purchase more goods and services with the same nominal income over time.
• Deflation can harm borrowers, who are bound to pay their debts in money that is worth more than the money they borrowed, as well as any financial market participants who invest or speculate on the prospect of rising prices.

What is the ‘Withdrawal of accommodative stance’? 

• The RBI has focused on its stance of ‘withdrawal of accommodation’ until all risks to inflation dissipate.
• An accommodative stance means the central bank is prepared to expand the money supply to boost economic growth 
• Withdrawal of accommodation will mean reducing the money supply in the system which will rein in inflation further.

• According to RBI, Foreign Investment means any investment made by a person resident outside India on a repatriable basis in capital instruments of an Indian company or to the capital of an Limited Liability Partnership (LLP). Foreign Direct Investment (FDI) is the investment through capital instruments by a person resident outside of India: 
  •  in an unlisted Indian company or 
  •  in 10 percent or more of the post-issue paid-up equity capital on a fully diluted basis of a listed Indian company. Foreign Portfolio Investment is any investment made by a person resident outside India in capital instruments where such investment is 
  • less than 10 percent of the post-issue paid-up equity capital on a fully diluted basis of a listed Indian company or 
  • less than 10 percent of the paid-up value of each series of capital instruments of a listed Indian company. Based on these definitions, Foreign investments on a small scale of less than 10 percent in a listed company cannot be treated as FDI. So, Assertion (A) is correct. 
• As per the Aravind Mayaram committee, any foreign investment of 10 or more than ten percent in a listed company will be classified as FDI. Further, in the case of an unlisted company, irrespective of a threshold limit will be classified as FDI. Hence the benchmark limit set by the committee to differentiate between FDI and FPI is 10% and not 25%. So, Reason (R) is not correct.

• Acquiring a loan currently requires (Loan Service Providers) LSPs to shoulder a host of responsibilities. These include sourcing, identity verification, underwriting, disbursement, recollections and dispute management. Each of these is a process unto itself, and their execution impacts the profits earned by an LSP. Taking these processes online would reduce the time and cost of loan disbursements and could reflect more favourable interest rates charged by lenders. The new technology, OCEN, bundles these lending processes and executes them online. It automates screening processes to decide on loan-worthy customers and the on boarding of new borrowers. These processes are being streamlined further by integrating the verification process with Aadhaar’s existing e- KYC system. OCEN is a credit protocol infrastructure that will mediate the interactions between loan service providers, usually fintech and mainstream lenders, including all large banks and NBFCs. So, Statement 1 is correct. 
• OCEN is being developed by iSPIRT, an Indian software industry think tank, not by the Reserve Bank of India. OCEN could be instrumental in building a credit marketplace or, more broadly, a digital ecosystem of lenders and loan service providers (LSPs). So, Statement 2 is not correct. 
• Digitalizing credit systems is also expected to help democratize them by connecting loan providers with customers who are not part of any formalized credit system. OCEN can also be used by non-bank small- scale lenders, thus expanding the scope of lending and borrowing. So, Statement 3 is correct.

• Non-debt receipts are those receipts that do not incur any future repayment burden for the government. Almost 75 percent of the total budget receipts are non-debt receipts. It refers to those government receipts that may lead to a decrease in assets but not an increase in liabilities. For example, disinvestments, recovery of loans, proceeds from the sale of public enterprises, etc., are non-debt-creating capital receipts. So, Option (c) is correct. 

ADDITIONAL INFORMATION:
RECEIPTS
About:

• Taxes and duties levied by the government form the biggest source of its income or receipts. 
•  The government spends this money on both operational and developmental needs. 
• Usually, there are two main sources of the government’s income – revenue receipts and capital receipts
• Revenue receipts can be defined as those that neither create any liability nor cause any reduction in the government's assets. 
• Capital receipts are receipts that create liabilities or reduce financial assets. They also refer to incoming cash flows.
• Capital receipts can be both non-debt and debt receipts. 
• Debt Receipts have to be repaid by the government. Around 25 percent of government expenditure is financed through borrowing. 
• A reduction in debt receipt (or borrowing) can be a big leap for the economy's financial health. Most of the capital receipts of the government are debt receipts.

Capital Account Convertibility refers to the freedom to convert local financial assets into foreign ones and vice versa. It is associated with changes of ownership in foreign/domestic financial assets and liabilities and embodies the creation and liquidation of claims on, or by, the rest of the world. The Reserve Bank of India established the Committee on Capital Account Convertibility (CAC) or Tarapore Committee to propose a roadmap for full convertibility of the rupee on the capital account. The members of the Committee included Dr. Surjit S. Bhalla, Shri M. G. Bhide, Dr. Kirit Parikh and Shri A V Rajwade. So, Option (d) is correct.

• GVA stands for Gross Value Added. GVA at basic prices is also called GVA Producer’s prices. The term Basic prices is an alternate term to describe Producer’s prices. It is different from market prices or buyer’s prices. While producers pay production taxes and receive production subsidies, buyers pay product taxes and get product subsidies. 
• Simply, GVA basic prices = GVA factor cost + Production Taxes - Production subsidies 
• The reward to employees (CE), entrepreneurs (OS) and consumption of fixed capital (CFC) is called factor cost. There is a difference between the tax on products and the tax on production. Tax on products includes taxes like sales tax and excise duty. It is the tax imposed as it was produced and sold. Tax on production refers to the tax imposed irrespective of production, like license fees and land tax. So, Option (a) is correct.

• Consumer Price Index is a measure of change in retail prices of goods and services consumed by defined population group in a given area with reference to a base year. Hence statement 1 is not correct. 
• This basket of goods and services represents the level of living or the utility derived by the consumers at given levels of their income, prices and tastes. 
• The CPI includes the prices of goods consumed by representative customers, hence it includes prices of imported goods. Hence statement 2 is correct. 
• The consumer price index measures change only in one of the factors i.e. prices. This index is an important economic indicator and is widely considered as a barometer of inflation, a tool for monitoring price stability and as a deflator in national accounts. 
• Consumer price index is used as a measure of inflation in around 157 countries. The dearness allowance of Government employees and wage contracts between labour and employer is based on this index. 
• In 2011 the CSO brought out a revised CPI, which was CPI (Urban), CPI (Rural) and CPI (Urban +Rural) with 2010 as the base price. CSO revised the base year of this newly set up index to 2012 in January 2015.

• Money multiplier is the ratio of the total money supply to the stock of high-powered money in an economy. Hence option (b) is the correct answer. o By definition, money supply is equal to currency plus deposits 
• M = CU + DD = (1 + cdr )DD ▪ where, cdr = CU/DD o High-powered money then consists of currency held by the public and reserves of the commercial banks, which include vault cash and banks’ deposits with RBI. 
• H = CU + R = cdr.DD + rdr.DD = (cdr + rdr)DD
  • Thus the ratio of money supply to high powered money ▪ M/H = 1+cdr/cdr+rdr > 1, as rdr > 1 
  • This is precisely the measure of the money multiplier. 
• The factors affecting the Money multiplier are the: Reserve ratio (SLR, CRR) and banking habits of the population, etc. 
  • For instance, assume that X bank has received a deposit of Rs 1000 and both SLR and CRR are maintained at 10 percent respectively i.e 20 percent in total. Now, the bank will keep Rs 200 as reserves (SLR and CRR) and the rest of the amount will be made available to the public in the form of loans. Now, a borrower takes a loan of Rs 800 from the bank either for consumption or for investment purposes. 
  • Suppose, the borrower has spent the loan taken for the purchase of an article. The seller of the article will receive the money and simultaneously deposit Rs 800 again with the bank. This happens because we have assumed that there is only a single bank in the economy. After receiving Rs 800 from the seller, the bank will again keep aside 20% of the amount i.e Rs 160 as reserves, and provide a loan to the public with the remaining amount. This process continues till the initial deposit of Rs 1000 becomes Rs 5000 i.e. 5 times the initial deposit. 
  • Reserve deposit ratio is the fraction of their total deposits which commercial banks keep as reserves.
  • Speculative demand is the demand for money as a store of wealth. 
  • Transaction demand is the demand for money for carrying out transactions.

• In India, the minerals are classified as minor minerals and major minerals. 
• According to section 3(e) of the Mines and Minerals (Development and Regulation) Act, 1957 “Minor Minerals” means building stones, gravel, ordinary clay, ordinary sand other than sand used for prescribed purposes, and any other mineral which the Central Government may, by notification in the Official Gazette, declare to be a minor mineral. (For the purposes of this Act, the word "minerals” includes all minerals except mineral oils- natural gas and petroleum). 
• Major minerals are those specified in the appendices to the Mines and Minerals (Development and Regulation) Act, 1957 (MMDR Act 1957) and the common major minerals are Major Mineral are minerals like Agate, Asbestos, Barytes, Bauxite, Cadmium, Coal. Copper, Gold, Iron ore, Lead, Lignite, Manganese, Nickel, Rock Phosphate, Tungsten, Uranium, Wollastonite, Zinc, etc. It may be noted that there is no official definition for “major minerals” in the MMDR Act. Hence, whatever is not declared as a “minor mineral” may be treated as a major mineral. 
• The major-minor classification has nothing to do with the availability (abundance or scarcity) of these minerals, though it is correlated with the relative value of these minerals. Further, this classification is based more on their end-use, rather than the level of production, level of mechanization, export, and import, etc. (eg. Sand can be a major mineral or a minor mineral depending on where it is used; the same is the case for limestone).
•  Hence option (c) is the correct answer.

• The process of moving from self-employment and regular salaried employment to casual wage work is called casualization of the workforce. Casual workers are defined as those who work for others in farm or non-farm enterprises and are paid wages that are daily or periodic in nature. All daily wage-earning employees and some categories of contract employees are casual laborers. Hence, option (d) is the correct answer.
• The wage-paid labor is largely non-unionized due to the casual and seasonal nature of employment and the scattered location of enterprises. This sector is marked by low incomes, unstable and irregular employment, and a lack of protection either from legislation or trade unions.
• Formalization of the workforce refers to the situation wherein there is a continuous increase in the percentage of the workforce in the formal sector and a simultaneous decline in the percentage of the workforce in the informal sector. Around 90 percent workforce in India is in the ―unregulated informal sector.

• The balance of payments (BoP) records the transactions in goods, services and assets between residents of a country with the rest of the world for a specified time period typically a year. There are two main accounts in the BoP — the current account and the capital account. Hence, statement 1 is correct. 
• The essence of international payments is that , a country that has a deficit in its current account must finance it by selling assets or by borrowing abroad. Thus, any current account deficit must be financed by a capital account surplus, that is, a net capital inflow. 
• A country is said to be in a balance of payments equilibrium when the current account deficit is financed entirely by international lending without any reserve movements. Hence, if a country is having BoP equilibrium it's official foreign exchange reserves remain unchanged. Hence, statement 2 is not correct. 
• Alternatively, the country could use its reserves of foreign exchange in order to balance any deficit in its balance of payments. The reserve bank sells foreign exchange when there is a deficit. This is called an official reserve sale. The decrease (increase) in official reserves is called the overall balance of payments deficit (surplus).

• Hybrid Annuity Model (HAM) has been introduced by the Government to revive PPP (Public-Private Partnership) in highway construction in India. 
• HAM is a mix of The Build Operate and Transfer (BOT) Annuity and Engineering, Procurement and Construction (EPC) Models. As per the design, the government will contribute 40% of the project cost in the first five years through annual payments (annuity). The remaining payment will be made on the basis of the assets created and the performance of the developer. Hence, statement 1 is not correct. 
• Unlike the BOT model, under HAM there is no toll right for the developer. Under HAM, Revenue collection would be the responsibility of the National Highways Authority of India (NHAI). Hence, statement 2 is not correct. 
• The advantage of HAM is that it gives enough liquidity to the developer and the financial risk is shared by the government. While the private partner continues to bear the construction and maintenance risks as in the case of the BOT (toll) model, he is required only to partly bear the financing risk. The government’s policy is that the HAM will be used in the case of stalled projects where other models are not applicable.

Manure is an organic material that is used to fertilize land, usually consisting of the feces and urine of domestic livestock, with or without accompanying litter such as straw, hay, or bedding. Farm animals void most of the nitrogen, phosphorus, and potassium that is present in the food they eat, and this constitutes an enormous fertility resource. In some countries, human excrement is also used. Livestock manure is less rich in nitrogen, phosphorus, and potash than synthetic fertilizers and hence must be applied in much greater quantities than the latter.

Advantages of Manure: The organic manure is considered better than fertilisers. This is because:

● It enhances the water holding capacity of the soil.

● It makes the soil porous due to which exchange of gases becomes easy.

● It increases the number of friendly microbes.

● It improves the texture of the soil.

Option (d) is the incorrect statement. Synthetic fertilizers provide specific nutrients to plants in a specified quantity, manure on the other hand provides all nutrients in varying proportions.

Option (b) is the correct answer.

Microbes are also used for commercial and industrial production of certain chemicals like organic acids, alcohols and enzymes.

Examples of acid producers are

Pair 1 is incorrectly matched. Aspergillus niger (a fungus) of citric acid, Acetobacter aceti (a bacterium) of acetic acid;

Pair 3 is incorrectly matched. Clostridium butylicum (a bacterium) of butyric acid and

Pair 4 is incorrectly matched. Lactobacillus (a bacterium) of lactic acid,

Pair 2 is correctly matched.

Yeast (Saccharomyces cerevisiae) is used for commercial production of ethanol.

Pasteurization is a process in which water and certain packaged and non-packaged foods (such as milk and fruit juice) are treated with mild heat, usually to less than 100 °C (212 °F), to eliminate pathogens and extend shelf life. The process is intended to destroy or deactivate organisms and enzymes that contribute to spoilage or risk of disease.

Statement 1 is correct. Milk is heated to about 700C for 15 to 30 seconds and then suddenly chilled and stored. By doing so, it prevents the growth of microbes.

Statement 2 is correct. Pasteurised milk can be consumed without boiling as it is free from harmful microbes. KB) The process was named after the French scientist Louis Pasteur, whose research in the 1880s demonstrated that thermal processing would inactivate unwanted microorganisms in wine.

Spoilage enzymes are also inactivated during pasteurization. Today, pasteurization is used widely in the dairy industry and other food processing industries to achieve food preservation and food safety.

Statement 1 is correct.

● Nitrogen is a vital macronutrient for most plants.

● Nitrogen is an inert gas which is necessary for life.

● It is the most abundant element in the atmosphere.

● A little over 78% of dry air on Earth is nitrogen.

● Atmospheric nitrogen, or dinitrogen, is unreactive and cannot be utilized by plants directly. Statement 2 is correct.

● Nitrogen is being changed into forms that are harmful, and the natural nitrogen cycle is being disturbed.

● Nitrogen compounds running off from farmland have led to water pollution problems around the world, while nitrogen emissions from industry, agriculture and vehicles make a big contribution to air pollution.

Statement 3 is also correct.

● Nitrogen can be a pollutant when it escapes into the environment and react with other organic compounds.

● It is either released into the atmosphere, gets dissolved in water sources such as rivers, lakes or groundwater, or remains in the soil. It can even be a factor in the greenhouse effect.

Option (c) is the correct answer.

Pair 1 is correctly matched. Lichens are organisms which is a symbiotic relationship between two separate organisms, which is an algae, and a fungus. The fungus provides shelter, water and minerals to the algae and, in return, the algae prepares and provides food to the fungus.

Pair 2 is incorrectly matched. Cuscuta (Amarbel) is a plant that does not have chlorophyll. It takes readymade food from the plant on which it climbs. The plant on which it climbs is called the host. Since it deprives the host of valuable nutrients, Cuscuta is called a parasite.

Pair 4 is not correctly matched. Rhizobium is a bacterium that can take atmospheric nitrogen and convert it into a usable form. But Rhizobium cannot make its own food. So it often lives in the roots of gram, peas, moong, beans and other legumes and provides them with nitrogen. In return, the plants provide food and shelter to the bacteria. They, thus, it has a symbiotic relationship with plants and not animals.

● It is a 2.7-meter infrared telescope sitting inside a Boeing 747SP aeroplane, flying at an altitude of 38,000-45,000 feet above the surface.

● It is globally unique and, with the start of regular operations in 2014.

○ It has been successfully used for scientific research during a total of approximately 800 flights.

● It was designed to observe cosmic objects in far-infrared wavelengths.

○ This allows researchers to watch star formation by looking through huge, cold clouds of gas

○ The project has generated 309 scientific studies.

○ In 2020, SOFIA discovered water molecules (H2O) on the sun-facing side of the Moon.

○ In 2019, SOFIA also discovered helium hydride — the first molecule formed in the Universe almost 14 billion years ago.

○ SOFIA also identified atmospheric circulation patterns in Jupiter.

○ It also mapped the magnetic field within G47, one of the Milky Way’s spiral arms.

Statement 1 is correct. Our mouth has the salivary glands which secrete saliva. Saliva contains the enzyme amylase, also called ptyalin, which is capable of breaking down starch into simpler sugars.

Statement 2 is correct. The inner lining of the stomach secretes mucus, hydrochloric acid and digestive juices. The mucous protects the lining of the stomach. The acid kills many bacteria that enters along with the food and makes the medium in the stomach acidic and helps the digestive juices to act. The digestive juices break down the proteins into simpler substances. Digestive juices are also known as ‘gastric juices’. These include ‘pepsin’ and ‘renin’. Pepsin converts proteins into simpler, more easily absorbed substances. Renin aids in the digestion of milk proteins.

Bio-piracy is the term used to refer to the use of bio-resources by multinational companies and other organisations without proper authorisation from the countries and people concerned without compensatory payment.

Statement 1 is correct: A pseudopod or pseudopodia is a temporary arm-like projection of a eukaryotic cell membrane. Pseudopods are used for motility and ingestion. They are often found in amoebas. It keeps on changing its shape. The projections of varying lengths protrude out of the body. These are called pseudopodia (pseudo: false; podia: feet).

Statement 2 is correct: A white blood cell (WBC) in human blood is another example of a single cell which can change its shape.

Statement 1 is incorrect. Bacteria can fix atmospheric nitrogen while free-living in the soil (examples Azospirillum and Azotobacter), thus enriching the nitrogen content of the soil. Fungi are also known to form symbiotic associations with plants (mycorrhiza). Many members of the genus Glomus form mycorrhiza. The fungal symbiont in these associations absorbs phosphorus from soil and passes it to the plant. Plants having such associations show other benefits also, such as resistance to root-borne pathogens, tolerance to salinity and drought, and an overall increase in plant growth and development.

Statement 2 is correct. Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments many of which can fix atmospheric nitrogen, e.g. Anabaena, Nostoc, Oscillatoria, etc. In paddy fields, cyanobacteria serve as an important bio fertilizer. Blue green algae also add organic matter to the soil and increase its fertility.

The United Nations General Assembly during its 74th Plenary Meeting proclaimed 2019 as the International Year of the Periodic Table of Chemical Elements. UNESCO has launched the International Year of The Periodic Table.

Statement 1 is incorrect. The Periodic Table, also known as the periodic table of elements is a tabular display of the chemical elements, which are arranged by atomic number, electron configuration, and recurring chemical properties. The structure of the table shows periodic trends. The seven rows of the table, called periods, generally have metals on the left and nonmetals on the right. The columns, called groups, contain elements with similar chemical behaviours.

Statement 2 is correct. 1869 is considered as the year of discovery of the Periodic System by the Russian scientist, Dmitri Mendeleev.

Every day we are exposed to a large number of infectious agents. However, the body is able to protect itself from the majority of such agents.

This overall ability of the host to fight the disease-causing organisms, conferred by the immune system is called immunity. Immunity is of two types:

(i) Innate immunity and

(ii) Acquired immunity Innate immunity is non-specific type of defence, that is present at the time of birth. This is accomplished by providing different types of barriers to the entry of the foreign agents into our body. Innate immunity consists of four types of barriers.

These are —

(i) Physical barriers: Skin on our body is the main barrier which prevents entry of the microorganisms. Mucus coating of the epithelium lining the respiratory, gastrointestinal and urogenital tracts also help in trapping microbes entering our body.

(ii) Physiological barriers : Acid in the stomach, saliva in the mouth, tears from eyes–all prevent microbial growth.

(iii) Cellular barriers: Certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes.

(iv) Cytokine barriers: Virus-infected cells secrete proteins called interferons which protect non-infected cells from further viral infection.