What holds the two strands of the DNA double helix together? A. Weak hydrogen bonds
B. Strong hydrogen bonds
C. Weak covalent bonds
D. Strong covalent bond

Hector is back from his morning run and is feeling lightheaded because his energy is depleted. which food item will provide him with a quick source of carbohydrates? a. fruit juice b. tuna fish c. scrambled eggs and butter d. beans

Aresearcher has developed two stains for use with seed plants. one stains sporophyte tissue blue; the other stains gametophyte tissue red. if the researcher exposes pollen grains to both stains, and then rinses away the excess stain, what should occur? a) the pollen grains will be pure red.b) the pollen grains will be pure blue.c) the pollen grains will have red interiors and blue exteriors.d) the pollen grains will have blue interiors and red exteriors.

Were does condensation occur? a) hydroshereb) lithosherec) boishered) atmosphere