By lowering the activation energy of the reaction
Weathering is the process by which rocks are broken down into smaller particles as a result of physical and chemical changes that are occurring in them. There are three major types of weathering these are: physical, chemical and biological weathering.
For the question given above, the type of weathering that is occurring in the picture of the given rock is PHYSICAL WEATHERING.
Physical weathering is the type of weathering in which the affected rock is changed in size and shape by means of some agents. The broken particles are usually of the same composition as the parent rock. The agents of physical weathering include: ice, plant roots, animal activities, abrasion and exfoliation. Physically weathered rocks are usually round in shape as a result of the abrasion process which they have undergone.<span />
Answer:
Cystic fibrosis mutation is recessive to normal allele because only one functional or normal allele is enough to produce a functional protein. So, if mutation is present in one allele then also, a normal protein can be made from normal allele. The presence of normal protein prevents the expression of disease.
In addition, mutated allele only results in the loss of function of protein which can be compensated by the expression of normal allele. It does not add any toxic effect to the protein. Consequently, the disease is inherited in autosomal recessive fashion.
In contrast, Huntington mutation not only alters the structure of the functional protein but also adds toxicity to it. The altered protein is enable to interact with 100s of other proteins and inhibit or decrease their function. So, if only one allele is present then also, the mutated protein will be produced and it will result in the phenotype. Consequently, it is inherited as autosomal dominant fashion.
