Answer to Question 1
Climate factors that are especially important in soil formation are precipitation and temperature. Water from rainfall erodes rocks and can also leach nutrients and minerals into the soil. It is also essential for plant and microorganism growth. Temperature influences the rate of plant growth, chemical reactions, and rock weathering.
Physical factors that influence the production of soil include water movement, water freezing and thawing, glaciations, and wind. The expansion and contraction of water and also minerals are especially important in degradation of rocks. In North America, glaciation was a major factor affecting soil formation. Glaciers and their melt water rearranged the landscapes by transporting and depositing rocks and soils. Today, water still has a significant effect in soil formation as it erodes, transports, and deposits soil sediment on landscapes, floodplains, and deltas.
Biological factors needed for soil production include the action of plant roots on rock. Plant can break rocks apart by wedging roots into cracks. Also, the decay of plants produces organic matter, which, during decomposition, produces acids that dissolve rocks. Organic matter from plants can also accumulate and create unique soils such as the mollisol soils. Lichens and fungi growing on rock surfaces can dissolve the rock by the excretion of chemical compounds.
Chemical reactions that are a component of soil production include oxidation, carbonation, and hydrolysis.
Answer to Question 2
Chisels
An example showing a modification that has occurred as a result of biological evolution
Contrasting (a) polygenic and (b) pleiotropic effects.
Selected Drugs Associated with Serious Adverse Effects During Breast-Feeding
Major Types of Hydrogen Bonds Found in Biomolecular Interactions
The biological clock obviously constrains the social clock