For natural selection to occur, several premises must be satisfied. Firstly, there must be variation in a population. If all individuals are the same, there is no variation on which selection can occur. Secondly, these traits must be heritable, meaning they are passed from parent to offspring. Natural selection cannot operate on traits that have no genetic basis. There must also be differential reproduction, which means that some individuals must reproduce more than others. When all of these factors occur, natural selection results in evolution as advantageous traits propagate throughout the population.
Natural selection is quite variable, as changes in the environment impact what traits are advantageous in a particular time and place. A good of example of this comes from Galapagos finches. These birds have varying beak sizes. Wide beaks are best for eating hard seeds, while long narrow beaks are more adept at exploiting the fleshy fruit from trees. Typically narrow beaks are more prevalent, but during drought conditions when trees cannot produce fruit, seeds become a more abundant food item. This results in those finches with wide beaks having more food available and reproducing more than those with narrow beaks. When droughts persist over many years, wide beaks replace narrow beaks as the most common, but this trend reverses when droughts end and fruits once again become available.
Answer:
Because they represent the leftover building blocks of the solar system-scientists can study these and learn about the composition of the solar system.
Answer:
c. recognize a member of their own species.
Explanation:
Imprinting is a form of social earning that occurs in a critical period based on early experience, in which an animal develop a sense of identity usually within few hours or days after birth.
In birds, for example in ducks, once an egg is hatched, the ducklings imprints on the first moving object they see which happens to be the mother. In other to keep track of the mother, they learn to respond to a characteristic sound that have been emitted by the mother. Through imprinting, they are able to distinguish their mother from the rest of the ducks. Imprintng helps birds to form an identity during early stage at birth, which helps them to recognize members of their own species.
There are many factors that affect the rate of chemical reactions and temperature is one of them.
Typically, the higher the temperature of a chemical reaction the faster the reaction occur, that is, the temperature and the rate of chemical reaction are directly related. This is due to the fact that increasing the temperature of the reaction increases the kinetic energy of the reacting particles and thus they are able to move faster and the reaction also occur faster. Thus, from the options given, the correct answer will be D [40 degree], this is because, it is the highest temperature out of all the options given.
Bacteria and restriction enzymes
,use enzymes to cut (and thereby destroy) foreign DNA (such as viral DNA), which would restrict the growth of the virus; own DNA is protected in some way (often by addition of methyl group CH3) to the sequence recognized by enzyme (thus preventing enzyme from binding there)
