what is the name of the region on duplicated chromosomes where the sister chromatids are most closely attached to each other? this region would be the 'waist' of the chromosome.

According to the law of conservation of energy, energy can neither be created nor destroyed. if this is true, why is there less energy in the top of the energy pyramid than there is in the bottom of the energy pyramid?

Identify any four organelles that should be present in the eukaryotic organism and describe the function of each organelle

What are the pros and cons of quadrat sampling?