What is the difference between the sugar found in dna and the sugar found in rna?

How does the molecular clock work? a. it analyzes the brain functionality of two different species.b. it examines and compares the physical characteristics of two different species.c. it illustrates relationships between two different species.d. it compares the number of mutations that exist in the dna of two different species.

All individuals have two alleles for a given trait. according to mendel's these alleles are passed down one each from both mother and father.

Which of the following cell structures is significantly different between gram- positive and gram-negative bacteria?