Persistent chlorinated hydrocarbon pesticides persist in the environment and accumulate in the foods chain causing harmful effects on the environment including posing a threat to humans health in the long term. Nonpersistent organophosphate pesticides are more toxic than the former but degrade after a short life span. Therefore they cause immediate harm in case one is in contact with them.
The fact that they do not accumulate in the environment, they are more favourable than chlorinated hydrocarbon pesticides. Chlorinated hydrocarbon pesticides will affect several generations due to their accumulation in the environment. However they don't need to be re-applied hence are less expensive
Clonal selection identifies a __ lymphocyte that needs to be cloned for production of a specific antibody.
is B.
Answer:
Positive
Explanation:
Hydrotropism is how a plant responds to water in a growing way. Positive means towards and negative means away. Roots grow toward the source of moisture, making that relationship positive.
Compounds are made up of elements.
Elements are the ones we pull straight out from the periodic table.
For example:
H2O, HCl, NaCl, NaOH --> these are all compounds
H, N, B, Ne, Na, Cl, O, K --> these are all elements.
