Can somone me out quick its a matter of life and death can some one tell me some plants in the relationship of mutualism parasitism and commensalism

What links the two strands in a dna helix together in the middle? a. phosphate groups b. sugar rings bonded together c. proteins d. bases with hydrogen bonds

What part of the brain is highlighted in the diagram below?

Consider the classification levels of a human. eukarya ,animalia ,chordata ,mammalia ,primates, hominidae ,homo ,sapiens .which is the most specific taxonomic level in the classification system above? a sapiens b homo c hominidae d primates