Beacuse they died long time ago
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa
Nitrofurantoin is an antibiotic drug that used for treating urinary tract infection. This drug is relatively safe but has toxicity to some organ such as liver, nervous and lungs.
Prior lab work will exclude the chance that the organ is damaged before treatment. It also can be used to monitor if there are major adverse effect happens to the patient.
Answer:
D) Competition between organisms
Explanation:
Random mating between organisms, absence of any factor of evolution (mutation, recombination, gene flow, migration etc.) and a large population size serve to maintain the allele frequency and thereby the phenotype frequency over generations. However, competition between organisms for any natural resource leads to natural selection of "better competing organisms" and increases their phenotype frequency in the population.