Question Discussion & Solution

Explanation:

• The purpose of regression testing is to confirm that a recent program or code change has not adversely affected existing features.
• Regression testing is nothing but a full or partial selection of already executed test cases that are re-executed to ensure existing functionalities work fine.
• This testing is done to make sure that new code changes should not have side effects on the existing functionalities. It ensures that the old code still works once the new code changes are done.

The purpose of regression testing is to select test cases partially or fully to ensure existing functionalities work fine. Thus, regression testing is primarily related to functional testing

Need of Regression Testing

• Regression Testing is required when there is a change in requirements and code is modified according to the requirement or when one of the following has been done.
  • New feature is added to the software
  • Defect fixing
  • Performance issue fix

Logic:

Wall, Roof, and Beam are parts of a Room.

But, 

House is a collection of Rooms.

Important PointsBeam means a long, sturdy piece of squared timber or metal used to support the roof or floor of a building.

Hence, house is the odd one out.

Data for B+ Tree:

Disk Block size = D= 256 byte

Block pointer = B = 2 byte

Key field = K = 8 byte.

Order = p

Formula:

p × 2 + (p – 1) (8) ≤ 256

Calculation:

p × 2 + (p – 1) (8) ≤ 256

2p + 8p ≤ 264

p ≤ 26.4

∴ p = 26

• ​Is a substance that contains living microorganisms.
• These, when applied to seeds, plant surfaces, or soil, colonize the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant. 
• Biofertilizers add nutrients through the natural processes of Nitrogen fixation.
• Examples: Rhizobium, Azotobacter, Blue-green algae, Azospirilium.

Key PointsBlue green algae:

• Blue-green algae (BGA) is a photoautotrophic, prokaryotic algae.
• They are free-living creatures and also known as Cyanobacteria.
• It fixes the atmospheric nitrogen in moist soils.
• So BGA has been recommended as a biofertilizer.
• The algae include unicellular as well as filamentous species.
• Some of the filamentous forms have specialized cells known as heterocysts.​

Important Points

Biofertilizers:

Thus, the manure also considered as bio-fertilizer is Blue green algae.

Additional Information

Compost: 

• Composting is a process in which both aerobic and anaerobic micro-organisms decompose organic matter.
• Farm compost is a mass of rotted organic matter made from farm waste like sugarcane trash, paddy straw, weeds and other plants.
• While town compost is a mass of rotted organic matter made from town refuses like night soil, street sweepings and dustbin refuse.

​Green Manure:

• Green manures are the crops that are grown primarily for building and maintaining soil fertility and structure.
• Green manure crops should be such that they can be grown quickly.
• Green manure crops include legumes such as vetch, clover, beans and peas; grasses such as annual ryegrass, oats, rapeseed, winter wheat and winter rye and buckwheat.
• Green manure crops provide nitrogen as the major nutrient.

Farmyard Manure:

• It is the decomposed mixture of dung and urine of farm animals.
• It also contains litter and leftover materials from roughages or fodder fed to cattle.

All except Wheat are cash crops whereas wheat is a food crop.

Cash crops mainly used for direct sale in the market rather than for family consumption. Food crops are used for family consumption.