Tissue culture cells shows sigmoid growth curve.

Correct Option: A

Tissue culture cells shows sigmoid growth curve.

In crop improvement programme, haploids are very important because they form perfect homozygotes which are helpful to get a pure line.

Correct Option: D

In crop improvement programme, haploids are very important because they form perfect homozygotes which are helpful to get a pure line.

Inorganic substances, oils, plant extracts used as insecticides are called first generation pesticides. Synthetic organic compounds are known as second generation pesticides. Insect hormones are third generation pesticides. Pheromones are the chemical substances which when released into an animal's surroundings, influence the behaviour or development of other individuals of the same species. Insect hormone analogues help in trapping the insects by confusing them as they mimic the odour of pheromones.

Correct Option: B

Inorganic substances, oils, plant extracts used as insecticides are called first generation pesticides. Synthetic organic compounds are known as second generation pesticides. Insect hormones are third generation pesticides. Pheromones are the chemical substances which when released into an animal's surroundings, influence the behaviour or development of other individuals of the same species. Insect hormone analogues help in trapping the insects by confusing them as they mimic the odour of pheromones.

Malathion is an organophosphate parasympathetic which binds irreversibly to cholinesterase. Malathion is an insecticide of relatively low human toxicity. However, malathion breaks down into malaoxon, which is 60 times more toxic than malathion. For this reason, if malathion is used or somehow enters an indoor environment, as it breaks down into malaoxon, it can seriously and chronically poison the occupants living or working in this environmnent. Malathion present in untreated water is converted to malaoxon during the chlorination phase of water treatment, so malathion should not be used in waters that may be used as a source for drinking water, or any upstream waters.

Correct Option: C

Malathion is an organophosphate parasympathetic which binds irreversibly to cholinesterase. Malathion is an insecticide of relatively low human toxicity. However, malathion breaks down into malaoxon, which is 60 times more toxic than malathion. For this reason, if malathion is used or somehow enters an indoor environment, as it breaks down into malaoxon, it can seriously and chronically poison the occupants living or working in this environmnent. Malathion present in untreated water is converted to malaoxon during the chlorination phase of water treatment, so malathion should not be used in waters that may be used as a source for drinking water, or any upstream waters.

2, 4-Dichlorophenoxy acetic acid is used for causing defoliation of forest trees. 2, 4-D or 2, 4 Dichlorophenoxy acetic acid is an auxin hormone. It stimulates the growth activities of the cells of the root due to which roots get destroyed and thus plants finally destroys. 2, 4-D is used as a defoliant for broad leaved dicots.

Correct Option: C

2, 4-Dichlorophenoxy acetic acid is used for causing defoliation of forest trees. 2, 4-D or 2, 4 Dichlorophenoxy acetic acid is an auxin hormone. It stimulates the growth activities of the cells of the root due to which roots get destroyed and thus plants finally destroys. 2, 4-D is used as a defoliant for broad leaved dicots.