| 1101 |
The proportion of observed variation in a trait that is due to genetic differences is called: |
Agriculture
Quantitative inheritance |
Medium |
| 1102 |
Triticale, the first man-made cereal, was developed by crossing: |
Agriculture
Plant breeding: history, objectives and methods |
Easy |
| 1103 |
The chemical commonly used to double the chromosome number in plants is: |
Agriculture
Plant breeding: history, objectives and methods |
Easy |
| 1104 |
Pure-line selection is best suited to: |
Agriculture
Plant breeding: history, objectives and methods |
Medium |
| 1105 |
The superiority of an F₁ hybrid over both its parents is called: |
Agriculture
Plant breeding: history, objectives and methods |
Easy |
| 1106 |
A breeder wants to transfer a single disease-resistance gene into an otherwise excellent variety. The most su… |
Agriculture
Plant breeding: history, objectives and methods |
Hard |
| 1107 |
Virus-free plants can be obtained through tissue culture of the: |
Agriculture
Plant breeding: history, objectives and methods |
Medium |
| 1108 |
The bacterium used as a natural vector to transfer genes into plants is: |
Agriculture
Plant biotechnology |
Easy |
| 1109 |
The insect-killing gene in Bt cotton is obtained from: |
Agriculture
Plant biotechnology |
Easy |
| 1110 |
Golden Rice was developed to increase the content of: |
Agriculture
Plant biotechnology |
Medium |
| 1111 |
Enzymes that cut DNA at specific base sequences are called: |
Agriculture
Plant biotechnology |
Medium |
| 1112 |
Selecting plants for a desired gene by testing their DNA rather than their appearance is called: |
Agriculture
Plant biotechnology |
Hard |
| 1113 |
What is the pH of a solution whose hydrogen ion concentration is 10⁻⁵ mol/L? |
Agriculture
pH and buffers |
Easy |
| 1114 |
A solution of pH 3 has how many times more hydrogen ions than a solution of pH 4? |
Agriculture
pH and buffers |
Medium |
| 1115 |
Which pair can form a buffer solution? |
Agriculture
pH and buffers |
Easy |
| 1116 |
For an acetic acid buffer (pKa = 4.76), what is the pH when the salt-to-acid ratio is 10? |
Agriculture
pH and buffers |
Hard |
| 1117 |
The main buffer system that keeps blood pH near 7.4 is the: |
Agriculture
pH and buffers |
Medium |
| 1118 |
Lactose, the sugar of milk, is made of: |
Agriculture
Biomolecules |
Easy |
| 1119 |
The bond linking amino acids in a protein is the: |
Agriculture
Biomolecules |
Easy |
| 1120 |
Which vitamin is water-soluble? |
Agriculture
Biomolecules |
Medium |
| 1121 |
Deficiency of vitamin B₁ (thiamine) causes: |
Agriculture
Biomolecules |
Medium |
| 1122 |
Amylase, which breaks down starch using water, belongs to which enzyme class? |
Agriculture
Biomolecules |
Hard |
| 1123 |
The main storage carbohydrate in plants is: |
Agriculture
Biomolecules |
Easy |
| 1124 |
The fungal cell wall is mainly made of: |
Agriculture
Micro-organisms |
Easy |
| 1125 |
Rod-shaped bacteria are called: |
Agriculture
Micro-organisms |
Easy |
| 1126 |
The antibiotic streptomycin is obtained from: |
Agriculture
Micro-organisms |
Medium |
| 1127 |
Which feature is true of viruses? |
Agriculture
Micro-organisms |
Medium |
| 1128 |
Anabaena and Nostoc, which fix nitrogen in rice fields, are best classed as: |
Agriculture
Micro-organisms |
Hard |
| 1129 |
Conversion of ammonium to nitrite in soil is carried out by: |
Agriculture
Role of micro-organisms |
Easy |
| 1130 |
The products of yeast fermentation of glucose are: |
Agriculture
Role of micro-organisms |
Easy |
| 1131 |
Which organism fixes nitrogen while living freely in the soil, without a host plant? |
Agriculture
Role of micro-organisms |
Medium |
| 1132 |
Wheat straw added to soil decomposes slowly mainly because it has a: |
Agriculture
Role of micro-organisms |
Hard |
| 1133 |
Loss of soil nitrogen as N₂ gas under waterlogged conditions is called: |
Agriculture
Role of micro-organisms |
Medium |
| 1134 |
The setting of milk into curd is due to: |
Agriculture
Role of micro-organisms |
Easy |
| 1135 |
The single cotyledon of a maize grain is called the: |
Agriculture
Seed structure |
Easy |
| 1136 |
In a monocot seed, the sheath that protects the plumule is the: |
Agriculture
Seed structure |
Medium |
| 1137 |
The protein-rich outer layer of the endosperm in cereal grains is the: |
Agriculture
Seed structure |
Medium |
| 1138 |
The scar on a seed marking where it was attached to the fruit is the: |
Agriculture
Seed structure |
Easy |
| 1139 |
In which crop do the cotyledons come above the soil during germination? |
Agriculture
Seed structure |
Hard |
| 1140 |
Food in a gram (chickpea) seed is stored mainly in the: |
Agriculture
Seed structure |
Easy |
| 1141 |
In flowering plants, the endosperm formed by triple fusion is: |
Agriculture
Reproduction, pollination and fertilisation |
Easy |
| 1142 |
Papaya, which commonly has separate male and female plants, is an example of a: |
Agriculture
Reproduction, pollination and fertilisation |
Easy |
| 1143 |
In maize, pollen is shed before the silks of the same plant are receptive. This is called: |
Agriculture
Reproduction, pollination and fertilisation |
Medium |
| 1144 |
Which crop is normally self-pollinated? |
Agriculture
Reproduction, pollination and fertilisation |
Medium |
| 1145 |
Formation of seed without fertilisation is called: |
Agriculture
Reproduction, pollination and fertilisation |
Hard |
| 1146 |
Potato is commercially propagated through: |
Agriculture
Reproduction, pollination and fertilisation |
Easy |
| 1147 |
The tag colour on a bag of certified seed is: |
Agriculture
Seed dormancy and types of seeds |
Easy |
| 1148 |
Breaking dormancy of hard-coated legume seeds by rubbing them with sand paper is called: |
Agriculture
Seed dormancy and types of seeds |
Easy |
| 1149 |
Foundation seed is produced from: |
Agriculture
Seed dormancy and types of seeds |
Medium |
| 1150 |
Keeping moist seeds at low temperature for several weeks to break dormancy is called: |
Agriculture
Seed dormancy and types of seeds |
Medium |