Answer:
The principal difference in development of Dorsoventral axis in deuterostomes and protostomes is something called inversion
Explanation:
In protostomates the neural tube is below the gut and the dorsal vessel is above the gut while in deuterostomates is the oppossite, there is an inversion and now, the neural tube is above the gut and the heart tube is below. In both cases the development is related to the gradient of expression of some genes, where the expresion of one gene supress the formation of one structure in one side of the axis.
In protostomates the TGT-B factor is expressed dorsally and supress neural tube formation and ventrally a sog gene is expressed and supress TGT-F factor allowing neural tube to develop. In deuterostomates, an homolog of TGT-B family gene BMP-4 is expressed ventrally while dorsally BMP inhibitors (sog gene like) are expressed.
Accordingly to some researchers, the first state of the common ancestor of deuterostomates and protostomates had an protostomate-like orientation in dorsoventral axis
Spines primarily have a protective function in plants. The spines can be sharp, and form a physical barrier against herbivores which may want to feed on the plant. Spines however also have other benefits. The spines on a jumping cactus allow segments of the cactus to stick to passing large animals or humans, thereby allowing the cactus to spread to other areas through asexual propagation. Spines are modified leaves, and spines have a much lower surface area than leaves, and therefore can reduce transpirative loss of water by the plant during harsh droughts. Some trees in alpine regions, such as pine trees, have developed spine-like leaves to prevent the accumulation of snow in the branches.
1. Early earth had no ozone layer, which means it was most likely extremely hot.
2. Young earth had no oxygen and life needs oxygen in order to survive.
3. There where so many natural disasters happening all the time, like volcanic eruptions and constant impact with meteorites and asteroids.
-Extra one (4. Earth originally had no ocean and water. Oceans eventually formed from the water vapor released from the volcanic eruptions, but before that there was nothing.)
C. Insulating the body
Insulating the body is not a function of a protein.
Lipids are macromolecules which provide insulation.
<span>A macromolecule is a large molecule. There are four groups of macromolecules: carbohydrates, proteins, nucleic acids and lipids. Lipids consist of glycerol and fatty acids and are constructed from fats, oils, waxes, phospholipids and steroids. A lipid's function is to insulate the body and provide warmth in cold conditions. It can be concluded that a person with very little body fat gets very cold easily and a person with a lot of body fat gets very warm very quickly.
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Answer:
Of all the energy that does reach Earth, slightly less than 34 percent is reflected back to space by clouds. The Earth itself reflects another 66 percent back to space. Less than one percent of the total energy that reaches Earth is used by plants for photosynthesis.
Explanation:
