The answer is <span>insect and pest populations decreased.
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DDT (dichlorodiphenyltrichloroethane) was used as an insecticide which is a substance used to kill insects. That resulted in decrease in insect and pest populations. It is a persistent and non-degradable insecticide, but as well organic pollutant readily accumulated to soils and consequently affects organisms.
Answer:
true
terrestrial planets
true
true
true
false
I am not sure about the last one
Answer:
A
Explanation:
It is believed that the moon was formed shortly (relative time) after the earth was newly formed. This occurred in a massive planet-sized collision that ejected a huge chunk of the earth out into space. The chunk, still within earth gravitational reach, began orbiting the earth becoming the moon. Both earth and moon are slightly more than 4 billion years old.
Answer:
A,B and E
Explanation:
- I+: I refers to the lac repressor, the + indicates that the repressor is functional
- P+: P refers to the promoter region and the + indicates that the promoter is functional
- Oc: O refers to the operator region, but the Oc indicates that the operator is constitutive ie. that it is always on/ can't be turned off.
- Z-: Z refers to the LacZ gene which produces β-galactosidase. Z- indicates that this gene is non-functional
- Y+: Y refers to the LacY gene which produces the permease protein. Y+ indicates that this gene is functional
So based on the breakdown above:
- C is not true because the lac operon is an inducible system. The operator needs to be able to be repressed. In this case the operator is constitutive (always on) which is not the correct form.
- D is not true because Z-, no β-galactosidase is produced.
Only A, B and E apply.
