Many of the organisms that had existed on the earth left no fossils because most of them can not meet the conditions that must be fulfilled before fossils can form. For fossils formation to occur, the organism soft tissue must decay leaving behind the hard part [majorly bone] in the sediment. Overtime, layers of sediment have to build up and pressed down on the buried remains. As time goes on, water and mineral seeped into the remains and form crystals.
Answer:
The correct answer is E. All of the above
Explanation:
Variation in offspring can be contributed by many different events that change the DNA sequence in gametic cells. These events are crossing over, mutation, independent assortment, and random fertilization.
During the gamete formation, the different genes are assorted independently from the other gametes which results in forming various possible combinations of genes in a gamete increasing the genetic variation.
Crossing over occurs during meiosis between the homologous chromosome that results in exchange of genetic material that brings genetic variation in gametes. During random fertilization, the two gametes fuse and genetic material of two different individual comes to make an offspring which forms a genetical different offspring.
Mutation in the gametic cell is transferred to the offspring during fertilization. Therefore all contributes to variation in offspring produced by sexual reproduction.
1.a.In agriculture cultural control is the practice of modifying the growing environment to reduce the prevalence of unwanted pests. Examples include changing soil pH or fertility levels, irrigation practices, amount of sunlight, temperature, or the use of beneficial animals or insects.
1.b. Cultural control is using the production or utilization methods of a commodity with a concern for insect management. Cultural control practices are usually multipurpose technical procedures that create environments that either avoid high-risk situations for infestations or develop unfavorable conditions for pests.
1.c.Simplicity and low cost are the primary advantages of cultural control tactics, and disadvantages are few as long as these tactics are compatible with a farmer's other management objectives (high yields, mechanization, etc.).
Your answer would be the second one B
