Question Discussion & Solution

Logic:

Train, Bus, and Boat are all vehicles,

Whereas a wheel is not a vehicle but a part of it.

Hence, "Wheel" is the odd word.

The correct answer is Primary key.

Key Points

• The foreign key is not necessarily the primary key in its current table.
  • It only has to contain the same information that is held in another table’s primary key.
  • Foreign keys are the columns of a table that points to the primary key of another table. They act as a cross-reference between tables.

Additional Information​ 

• A report generator is a computer program whose purpose is to take data from a source such as a database, XML stream or a spreadsheet, and use it to produce a document in a format which satisfies a particular human readership.
• The data dictionary is a set of information describing the contents, format, and structure of a database and the relationship between its elements, used to control access to and manipulation of the database.
• Schema objects are logical structures created by users. Objects such as tables or indexes hold data or can consist of a definition only, such as a view or synonym.

The correct answer is Mercury.

Key Points

• Mercury is the closest planet to the Sun.
• The planet probably received this name because it moves so quickly across space.
• Temperature variations on Mercury are the most extreme in the solar system ranging from 90 K to 700 K.
• Mercury is the second densest major body in the solar system, after Earth.

Important Points 

• The solar system is made up of the sun and everything that orbits around it, including planets, moons, asteroids, comets, and meteoroids.
  • It extends from the sun, called Sol by the ancient Romans, and goes past the four inner planets, through the Asteroid Belt to the four gas giants and on to the disk-shaped Kuiper Belt and far beyond to the teardrop-shaped heliopause.
  • Scientists estimate that the edge of the solar system is about 9 billion miles (15 billion kilometers) from the sun.
  • Beyond the heliopause lies the giant, spherical Oort Cloud, which is thought to surround the solar system.

Additional Information 

•  The sun is at the center of our solar system and is its largest object, accounting for 99.8% of the solar system's mass.
  • Our sun is a giant, raging ball of fire powered by nuclear reactions, and it provides the energy that sustains life on Earth.
  • The life-giving star is a yellow dwarf star made up of gas: about 91% hydrogen and 8.9% helium, according to NASA.
  • Compared with other stars, the size of the sun is relatively small and it's just one of the hundreds of billions of stars in our home galaxy, the Milky Way. 

Concept:

ER model describes data as entities, relationships, and attributes. It is a high-level conceptual data model. This model is used to define the data elements and relationships for a specified system.

Entity:

The entity is a thing in the real world with an independent existence. An entity may be an object with physical existence. For example particular person, car or it may be an object with a conceptual existence For example company, job, etc.

Attributes:

Each entity has attributes – the particular properties that describe it.

Relationship:

It is used to describe the relation between two entities.

Explanation:

E-R Diagram is design level task and Relational model is implementation.

The relational model is implemented from E-R Diagram and in this, it gets rid of the multivalued attributes.

Relations produced from the E - R Model will always be in 1NF, that is, Simple atomic values with non-multivalued attributes.

NOTES:

The correct answer is Only I.

Key Points

• In asexual reproduction, only one parent is involved and sex cells are not involved. 
• It is observed in both multicellular and unicellular organisms.
• Types of asexual reproduction are:
  • Binary Fission
  • Budding
  • Fragmentation
  • Vegetative Propagation
  • Sporogenesis
• Spore formation comes under sporogenesis. Hence, statement 1 is correct.
• Spore formation is a kind of reproduction process in plants by produces tiny spores and propagates through them.
• Spore Formation is a method of asexual reproduction. 
• Spore formation can be seen in the bread mould / Rhizopus.
• The airborne spores land on bread under favourable conditions and they germinate and produce new bread mould plants.
• Each spore is covered with a protective coat to withstand unfavourable conditions.
• Plants like ferns, mucor, and mosses are also reproduced through spore formation
• Spores are present in a sac called sporangia.
• Fragmentation is a type of asexual reproduction. Hence, statement 2 is incorrect.

Additional Information

• Pollination is a method of Sexual Reproduction.
• Self-pollination:
  • The transfer of pollen grains from another to the stigma of the same flower is called self-pollination.
• ​Cross-pollination:
  • The transfer of pollen grains from the anther of one flower to the stigma of another flower is called cross-pollination.
• Vegetative propagation:
  • It is a form of asexual reproduction of a plant wherein a new plant grows from a fragment of the parent plant.