The synthesis of thyroid hormones requires the iodination of tyrosine molecules and the combination of two iodinated tyrosine residues
I. Each carbon atom can form single bonds with up to four other carbon atoms. II. Each carbon atom can form double bonds with up to two other carbon atoms. III. Carbon atoms can join together to form chains or rings. IV. A single molecule of some compounds can contain thousands of carbon atoms.
Answer:
All the given choices
Explanation:
Carbon is a very interesting element which is the backbone of most organic compounds.
Organic compounds are made up of carbon. Carbon forms a wide range of compound due to the following properties;
- An atom of carbon has 4 valence electrons and can bond with 4 other carbon.
- Carbon can form single, double and triple covalent bonds.
- They can join together to form rings or chains.
Molecules with similar shapes have similar biological effects, because shape (structure) dictates effects (functions).
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.
