Answer:
Atmosphere refers to the thin blanket of air that surrounds the earth.
It serves many important functions such as:
- It contains a mixture of gases that are essential for the existence of life on earth. For example, carbon dioxide is essential for photosynthesis and oxygen is essential for cellular respiration.
- It also serves as the reservoir of water in the form of water vapor. Thus, it forms an important constituent for the water cycle.
- It maintains the temperature of the earth. Through the greenhouse effect, it maintains the temperature of the earth in limited ranges.
- It protects the earth from harmful rays of the sun. For example, ozone inhibits the entry of most of the UV rays of the sun into the earth environment.
Answer:
4. cannot be made by the body and therefore must be consumed to maintain health.
Explanation:
Essential nutrients are nutrients that our body cannot synthesized and also those nutrients our body cannot produced in sufficient quantity, for the normal functioning of the body. These nutrients have to be obtained from the food we consume to support our life and health.
Essential nutrients obtained from food include carbohydrates, fats and oils, proteins, water, as well as certain vitamins and minerals. These essential nutrients that we get from our food are needed for good growth and development, prevention of diseases, as well as for maintaining good health.
The correct answer should be B. CARBOHYDRATES
Answer:
Promoter is located upstream and terminator is located downstream relative to the transcription start site.
Explanation:
Transcription start site is the site from where the transcription starts which is denoted by +1. The sequence of nucleotides which is present backword to them called upstream sequence and nucleotide sequence which is present in the forward direction of transcription start site are called downstream sequence.
Promoter sequences are present upstream to the transcription start site and are denoted with a minus sign and terminator sequence is present downstream to the transcription start site.
Answer:B
Explanation:provitamin A is preformed vitamin A .. The best source of these are animal sources than plant sources.. Best sources include diary foods,, meat and fish.
