Correct Answer: A. thyroxine

Correct Answer: A. Large-scale farming for profit and market-oriented production

Explanation

Commercial agriculture refers to farming practices that are primarily focused on generating profit through the sale of agricultural products in the market. It involves large-scale cultivation of crops or raising of livestock with the aim of maximizing productivity and economic returns.

Correct Answer: B) higher the price of a commodity leads to lower quantity demanded

Explanation

(a) Ways in which weeds are beneficial to the farmer

• Weeds help in checking soil erosion
• Some weeds are useful as food for humans
• Some weeds serve as feed for livestock
• Certain weeds have medicinal properties
• Weeds can be ploughed into the soil to replenish soil nutrients
• Some weeds are used for roofmg, making mats, baskets etc
• Weeds can be cut and used as mulch
• For compost making
• Leguminous weeds harbour bacteria that help to fix atmospheric nitrogen into the soil

(b)Classification of insect-pests based on their mode of feeding and examples:

(i) Biting and chewing insects e.g locusts, grasshoppers, termites, mantids, the stick and leaf insects, beetles, leaf worms, army worms, budworms, crickets, larvae of lepidopetera

(ii) Piercing and sucking insects e.g capsids, cotton stainers, whiteflies, scale insects mealy bugs, green shield bugs, aphids, thrips, tsetsefly, ticks

(iii) Boring insects e.g beetles, weevils, stem borers, fruit borers

(c) Ways by which pasture can be made available to cattle

• Prepared as hay for livestock
• As silage
• Cut and carry as fresh fodder/zero grazing
• Animals can be taken out for grazing

Explanation

(a) Farm surveying is a series of activities, mainly measurements, performed in the field to locate the farm land, delineate its boundaries, determine its size and produce a map of the farmland.

(b) Six surveying instruments include (i) Prismatic compass (ii) Gunter's chain (iii) Measuring tape (iv) Ranging pole (v) Theodolite (vi) Beacon/Pillars

(c) (i) Ranging poles: These are wood or metal poles used in marking spots or stations during surveying.

(ii) Gunter's chain: This is a surveyor's chain of 100 links. 22 meters long used to measure a piece of land.

(iii) Measuring tapes: These are used in taking short or detailed measurements

(iv) Prismatic compass: This is used to measure horizontal angles between a reference median and a point of interest in order to find the orientation of the point and its bearing.

Correct Answer: D. nicotiana tabacum

Correct Answer: D. variegated grasshoppers

Correct Answer: C. To abandon the development of rural area

Correct Answer: D. solution

Correct Answer: A. bacteria and fungi