There are 7 unifying themes in biology
1.Cell structure and function
2.Reproduction
3.Metabolism
4.Homeostasis
5.Heredity
6.Evolution
7.Interdependence
In general, yes, the dorsal blood vessel of a worm be seen from the worm's exterior because a worm's "skin" is very thin. Although of course there are exceptions.
Answer:
Minerals can form in all geological environments, which allows them to have a wide range of chemical and physical conditions. Two forms of this are temperature and pressure. There are 4 main categories of mineral formations. Igneous is where the minerals crystalize from a melt. Sedimentary is where the raw materials of the mineral are particles from other rocks that have suffered from erosion and weathering. Metamorphic is where new minerals are created from earlier ones owing to the effects of change. Most of the time it's from increasing temperature and/or pressure. Hydrothermal is where the minerals are chemically precipitated from hot solutions in the earth.
Answer:
The average trait value changed in one direction.(In this case, larger size)
Explanation:
In evolution a natural selection can be disruptive, directional or stabilizing
In stabilizing no extreme trait is favored hence provides intermediate values .
Disruptive selection both extreme traits are favored over the intermediate trait.
Directional, the enviroment will favor the survival of one trait hence a change in direction either towards the left or the right.
In the case of swallow cliff mortality, selection favored the larger size.