Answer:
directional selection
Explanation:
Directional selection is the most common type of natural selection and occurs when some individuals with characteristics favorable to the conditions of the environment in which they live, have survival advantages over individuals who do not have this advantage, who end up dying.
Imagine, for example, a graph showing the directional selection in the same species of moths. Moths of the same species have white and brown collations, in summer, brown moths can camouflage themselves on tree trunks, while white moths cannot and are easily captured by their predators, which means that the amount of white moths decrease. In this graph, the population of white moths would be at a minimum, at the same time that the population of brown moths would be at maximum.
However, with the arrival of the reverse, snow begins to cover the trees, allowing white moths to camouflage themselves more easily. The brown moths, then, are very exposed to predators, causing their population to reach the minimum while the population of white moths reaches the maximum.
Zygote implants itself in the uterus.
Answer:
The correct option is 3. "At pH 6.5 the enyzme is 50% active"
Explanation:
For the titratable group to be protonated and cause the enzyme to be in the active state, it needs to have gained a hydrogen cation (H+). In order for that to happen, there must be enough hydrogen cations in the environment of the enzyme, and hence, an acidic pH is required in this case.
Edwin Hubble used the Doppler effect to determine that the universe is expanding. After years of scientific research and observation of different celestial bodies through a telescope, Hubble found that the light from distant galaxies was shifted towards the red end of the spectrum. This red shift indicates that stars are moving away from us and from each other. This phenomenon is called the 'expansion of the universe', also known as the big band theory.