Question

lab: natural selection
warm-up active
check your basic understanding of natural
review
check all statements below that are true.
all organisms must compete for survival.
when organisms struggle to survive, they usually mutate to increase chances of reproduction.
some organisms have phenotypes that make them better competitors than others in their
environment.
animals undergo natural selection, but plants and other organisms generally do not.
natural selection continues to occur even today.
phenotypes found in the most successful members of a species become the most prevalent after
several generations.
a decrease in food availability will increase the variation in a population.
done

Explanation:

• All organisms must compete for survival: This is a fundamental concept in natural selection. Resources are limited, so organisms compete for them to survive.
• Some organisms have phenotypes that make them better competitors than others in their environment: Phenotypes are the physical expressions of genes. Traits that give an organism an advantage in obtaining resources or avoiding predators make it a better competitor.
• Natural selection continues to occur even today: Natural selection is an ongoing process. Environmental changes (e.g., climate change, introduction of new predators or competitors) mean that organisms are constantly evolving through natural selection.
• Phenotypes found in the most successful members of a species become the most prevalent after several generations: Successful organisms (those that survive and reproduce) pass on their genes (and thus the phenotypes associated with those genes) to the next generation. Over time, these advantageous phenotypes become more common.

• When organisms struggle to survive, they usually mutate to increase chances of reproduction: Mutations are random. Organisms do not "mutate on purpose" to increase reproduction chances. Mutations that happen to be beneficial are selected for, but the mutation itself is not a response to struggle in a directed way.
• Animals undergo natural selection, but plants and other organisms generally do not: All living organisms (plants, animals, fungi, bacteria, etc.) undergo natural selection. They all have to interact with their environment, compete for resources, and reproduce.
• A decrease in food availability will increase the variation in a population: A decrease in food availability usually leads to more intense competition. This can lead to selection for certain traits (decreasing variation if a particular trait is strongly favored) rather than increasing variation.

Answer:

• All organisms must compete for survival.
• Some organisms have phenotypes that make them better competitors than others in their environment.
• Natural selection continues to occur even today.
• Phenotypes found in the most successful members of a species become the most prevalent after several generations.