How can eukaryotic tell which strand is the old dna and which one is the new dna strand to fix error?

Agroup of plant cells was exposed to radiation, which damaged the chloroplasts and caused them to lose function. if the mitochondria were unharmed, what would happen to the overall function of the plant cells? a. the cells would not be able to make food, but would be able to release energy from biomolecules. b. the cells would not be able to replicate dna, but would be able to break down waste. c. the cells would not be able to break down waste, but would be able to replicate dna. d. the cells would not be able to release energy from biomolecules, but would be able to make food.

What type of plant is good for a bioassay and where can i buy it? i only have a month.

Are the layers of rock above and below the coal older or younger?