Answer:
When the required direction of transport is opposed to concentration levels, a cell <u>will </u> expend energy to force<u> ions</u> across its membrane.
Explanation:
If the concentration gradient is opposite to the direction of transport of minerals, then the cell will use energy to transport mineral ions from a lower concentration to a higher concentration. The most common process through which this happens is termed as the active transport.
The process of active transport is opposite to passive transport. In passive transport, molecules move from a higher concentration to a lower concentration.
Secondary succession occurs after the initial succession has been disrupted and some plants and animals still exist. The disruption occurs afer an event like a forrest fire or hurricane destroys the forest.
Answer:B. Sunlight provides energy to producers
Explanation: photoautotrophs (plants) produce energy from sunlight by photosynthesis. This is the only energy production based on an external source of energy. Plants, whether alive or dead, are consumed by heterotrophs - bacteria, fungi and animals. The nutrients and energy from dead heterotrophs (and some live ones) are recycled by both autotrophs and heterotrophs.
The heart is a vital organ, and its functioning is essential to life.
All your other organs may fail, and you will still be alive. Even if your brain stops working, and your heart is healthy, you will be alive in the vegetative state where you won't be conscious at all. However, once your heart stops working, you die, which means it is the most important organ in your body.
Answer:
<u>B. Animals do not use carbon dioxide as an energy source; they use carbohydrates.</u>
Explanation:
The most readily form of energy that an animal requires is carbohydrate molecules. Monosaccharide carbohydrates can be easily broken down and hence are the best sources of energy. Carbohydrates are broken down in the process of cellular respiration to generate ATP. ATP is the energy driving molecule which is required by every cell of an organisms body to carry out its normal metabolic functions. Hence, animals use carbohydrates as a source of energy, not carbon dioxide.
