Answer:
<u>A chemical bond between the phosphate group of one nucleotide and the sugar of a neighboring nucleotide holds the backbone together. Chemical bonds (hydrogen bonds) between the bases that are across from one another hold the two strands of the double helix together.</u>
Explanation:
Answer:
Producers are always at the beginning of a food chain. Producers begin every food chain because they can make their own food.
Each time an organism is consumed, 90% of the energy is lost as heat. that leaves only 10% for the carnivore
The wood in a matchstick is made of cellulose, a polymer of glucose molecules. When you light the matchstick, heat and light are given off, indicating that an exothermic reaction is occurring.
There are two types of reactions:
1. Exothermic reactions: In these reactions, the reactants combine to form product and heat is liberated. Example, burning of fuel.
2.Endothermic reactions: In these reactions, the reactants combine to form product and heat gets absorbed from the surroundings. Example, photosynthesis in plants where the energy of the Sun gets absorbed.