Explanation

• The word “since” refers to a specific point in the past, so the past simple tense is required.
• Correct sentence: “We haven’t seen each other since he left.”

Last verified on 19-01-2026

Explanation

• In PCR (Polymerase Chain Reaction), the first step is denaturation, where the double-stranded DNA is heated to separate into single strands.
• This allows primers to bind in the next step.

Additional information:

• Second step: Annealing – primers attach to single-stranded DNA.
• Third step: Extension/Replication – DNA polymerase synthesizes new DNA strands.

Last verified on 19-01-2026

Explanation

• Maize (corn) completes its life cycle in one year, from sowing to harvest.
• It grows, flowers, produces seeds, and dies within a single season.

Additional information:

• Biennial crops: Take two years to complete life cycle (e.g., carrot, beetroot).
• Perennial crops: Live and produce for multiple years (e.g., apple, sugarcane).

Last verified on 19-01-2026

Explanation

• "Take after" means to look like or behave like a parent or elder relative.
• It is used to show similarity in appearance or character.

Last verified on 19-01-2026

Explanation

• Reducing the oxygen level around stored fruits slows down respiration and ripening, increasing shelf life.
• This method is used in controlled atmosphere storage.

Additional information:

• Increasing CO₂ can also slow ripening but must be carefully controlled.
• High oxygen accelerates ripening and spoilage.

Last verified on 19-01-2026

Explanation

• Fiber crops are grown for their fibers used in textiles and ropes.
• Main fiber crops include jute and cotton.

Additional information:

• Cotton: Used for clothing and industrial fabrics.
• Jute: Used for making bags, ropes, mats, and carpets.
• Other fiber crops: Flax, Hemp, Coir.

Last verified on 19-01-2026

Explanation

• Protandry is a condition in plants where male flowers mature before female flowers to prevent self-pollination.
• Commonly found in maize (corn).

Additional information:

• In maize, tassels are male flowers and silks are female flowers.
• Helps in cross-pollination and genetic diversity.

Last verified on 19-01-2026

Explanation

• Objective pronouns are used as the object of a verb or preposition.
• Examples include: me, us, him, her, them, you, it.

Additional information:

• Subjective pronouns: I, we, he, she, they (used as the subject of a sentence).
• Reflexive pronouns: Myself, ourselves, himself, herself, themselves (used when subject and object are the same).

Last verified on 19-01-2026

Explanation

• Club root disease affects plants in the Cruciferae family, especially cabbage and turnip.
• It is caused by the soil-borne pathogen Plasmodiophora brassicae, leading to swollen and distorted roots.

Additional information:

• Symptoms: Stunted growth, yellowing leaves, and club-shaped roots.
• Common in acidic soils and can persist for many years in the soil.

Last verified on 19-01-2026

Explanation

• Witches’ broom disease affects plants, causing abnormal clustering of branches like a broom.
• It is caused by a virus that disrupts normal growth patterns.

Additional information:

• Commonly affects cacao, citrus, and some ornamental plants.
• Symptoms: Dense, bushy growth, stunted leaves, reduced fruit yield.

Last verified on 19-01-2026