Answer:
1. Mutation- enhances genetic variation
2. Selection- may raise, lower, or maintain genetic variation
3. Genetic drift- diminishes genetic variation.
4. Gene flow- could either enhance or reduce genetic variation
Explanation:
1. Mutation denotes changes in an organism's DNA. The mutations lead to new adaptive traits that evolve, which increases the genetic diversity of organisms.
2. Natural selection favors organisms best suited to their environment. Thus, selection can increase, decrease, or keep variation in a population steady.
3. Genetic drift occurs due to random events altering a population's gene pool. When this phenomenon transpires, the genetic variation within that population typically decreases.
4. Gene flow involves changes to the gene pool due to immigration and emigration. This factor can thus increase or decrease genetic variation.
They demonstrate resilience. In 1988, Yellowstone National Park experienced wildfires that engulfed over a million acres and adjacent territories. However, after three decades, the park's forests have started to regenerate. This recovery stems from the resilient ecosystems, characterized by species that are adapted to endure periodic severe wildfires. Provided there is sufficient water, these plants will regrow. The lodgepole pines that burned in the wildfires are not fire-resistant, but their regrowth over the years illustrates resilience.
The answer is C. This conclusion is drawn from the understanding that roan coat coloration arises in heterozygous offspring produced by homozygous red and white parents, thereby nullifying option A, which involves two red parents. In B, the cross between CRCR and CRCW generates two roan and two red offspring but no white - eliminating that as a viable option. Option D, involving red and white homozygous parents, solely produces roan offspring. In option E, a cross of CWCW with CRCW yields two roan and two white but no red. Thus, option C remains valid as the cross of CRCW with CRCW results in 1 red, 2 roan, and 1 white offspring, matching the desired ratio.
Some organisms have adapted in such a way that they stay inactive during the active hours of their predators. The adaptive theory of sleep posits that prey tend to rest at night when their predators are most active, using this time to rejuvenate and gather energy for various tasks. By remaining inactive and sheltered, prey decrease their chances of being hunted.
Thus, the answer is the adaptive theory of sleep.
