A star’s life expectancy depends on its mass. Generally, the more massive the star, the faster it burns up its fuel supply, and the shorter its life. The most massive stars can burn out and explode in a supernova after only a few million years of fusion. A star with a mass like the Sun, on the other hand, can continue fusing hydrogen for about 10 billion years. And if the star is very small, with a mass only a tenth that of the Sun, it can keep fusing hydrogen for up to a trillion years, longer than the current age of the universe.
Answer:
Among others, two adaptations might be
- Avoiding corporal heat loss
- Increasing oxygen absorption
Explanation:
Up in the mountains, there is low oxygen, food is scarce, and adverse meteorological conditions. Animals and plants need to develop different strategies to survive. These adaptations involve not only physical and physiological changes but also behavioral changes. To mention a few adaptations, we can name:
- Avoiding heat loss. Temperature tends to be very low at highs, so, to <u>avoid heat loss,</u> animals develop shorter legs, tails, and ears. By doing this they reduce the area or surface of heat loss and also avoid getting frozen. In mammals, the coat is also very important. A thick coat helps them maintain a constant body temperature and keep warm. Some amphibians might also develop a thicker skin as they can not regulate their temperature, and it also helps them not to dehydrate.
- Camouflage: Coat is also helpful in camouflaging. Mammals´ hair color depends on their environment. Some animals, such as hares, can also change their fur color depending on the season. During snow seasons they turn white, and during the warmer season, they turn yellow or brown.
- Size and metabolism: Small mammals lose heat very fast, so they need to keep active and feeding most of the time. They have an elevated metabolism to keep warm. On the contrary, big animals, such as bears, need to hibernate to reduce their metabolism and get to survive, otherwise, they would need many reserves to cover their energetic requirements.
- Oxygen absorption: Some animals have adapted to the lack of oxygen by increasing their heart and lungs capacity as well as their capability to absorbing more oxygen from the blood.
Answer: B. Linoleic acid
Explanation:
Linoleic acid is an essential fatty acid. It is a polyunsaturated fatty acid for humans. It is a colorless or white colored oil. It is typically insoluble in water. It cannot be found deficient in the human body as humans obtain it in the form of different kind of food items like vegetable oils, seeds, eggs, meat and nuts. Thus it is abundantly consumed in the diet.
