A DNA molecule consists of two strands of nucleotides twisted together to form a double helix. The sugar-phosphate backbone is found on the outside of this helix and the bases are found braching towards the middle. Hydrogen bonds join the thenitrogenous bases and hold the two strands together.
Therefore your answer is sugar and phosphate.
Answer:
The correct answer is: <em>C. Increased average lifespan to 78 in the US.</em>
Explanation:
Science has impacted human health by increasing the average lifespan to 78 in the US. Over the last couple of decades, the life expectancy of Americans has increased significantly than what it was 200 years ago. This can be attributed to:
1. Vaccinations- Since the invention of vaccinations, diseases such as tuberculosis, cholera and polio which were major causes of death 200 years ago have virtually been eradicated in the US.
2. Abundant and safer foods available- Commercial and large scale farming has made a wide variety of nutritious foods easier to obtain.
3. Improved sanitation- Safer drinking water, sewage treatment and stricter food inspection has significantly reduced the rate of illnesses due to poor hygiene and sanitation.
In these ways, science has impacted human health by increasing the average lifespan to 78 in the US.
Answer:
The answer is A
Explanation:
The answer is A because the sun is not a producer and only helps producers.
<span>Protein channels are needed to transport substances because it accelerates the transport process. Very few substances enter or leave cells without being attached to a transport protein. Different types of substances require different types of proteins to transport them. Protein channels transport water or ions downwards and ATP-powered pumps transport molecules or ions upwards. ATP generates energy to transport the molecules upwards. Gravity is used to transport the water molecules downwards. So, in a nutshell, if substances need to be transported from the top of the body downward, the force of gravity is used to transport the substances down. If substances need to be transported upwards, ATP, a coenzyme, is used to generate energy to transport the substance upwards</span>
The subunits are called nucleotides
