Answer:
The correct option is B. Activation energy
Explanation:
The activation energy is usually used to designate the minimum energy necessary for a given chemical reaction to occur, that is, the basic requirement for the reaction to proceed.
For a reaction to occur between two molecules, they must collide in the correct orientation and have a minimum amount of energy. As the molecules approach, their electron clouds are rejected. This requires energy (activation energy) and comes from the heat of the system, that, is, from translational, vibrational energy, etc of each molecule. If the energy is sufficient, the repulsion is overcome and the molecules are close enough for a rearrangement of the bonds of the molecules.
The concept of Activation energy was introduced by Arrhenius in 1889. Arrhenius suggested that molecules must prossess a minimum amount of energy to react. That energy comes from the kinetic energy of the clliding molecules. Kinetic energy serves to cause reactions, but if the molecules move very slowly, the molecules will only bounce when they collide with other molecules and the reaction does not happen. In order for the molecules to react, they must have a total kinetic energy that is equal to or greater than a certain minimum value of energy called activation energy.
These pills inhibit ovulation processes as well as implantation. Therefore, women can prevent unplanned pregnancy by using these pills
Answer:
The correct answer will be option-B.
Explanation:
Deoxyribose nucleic acid or DNA is the genetic material of the organism which is made up of nucleotide monomer. The structure of DNA is made up of two strands of nucleotides coiled in a helical structure thus providing a double-helical shape to the structure.
Each nucleotide of a strand is composed of a five-carbon sugar, phosphate group and nitrogenous bases. These molecules are arranged in anti-parallel fashion in DNA which provides the polarity to the DNA strand. One strand is read from the 5' to 3' direction whereas another form 3'to 5' direction.
Thus, Option-B is the correct answer.
The main reason for the difference in the mass extinction occurring today and previously is the pace of the current extinction. The extinction is taking place globally and involves hundreds of species at the same time. In less than 50 years, we have lost numerous species. In contrast to this, previously during the mass extinction, only a few species were lost, and other managed to survive. But, not the status is opposite due to the magnitude of the extinction.
Only a fraction of the energy<span> available at one trophic </span>level<span>is </span>transferred to the next<span> trophic </span>level<span>; the fractions can vary between 1-15%, with an average value of 10%. Typically the numbers and biomass of organisms decreases as one ascends the </span>food chain<span>.</span>
