Final answer:
Amoebas are indeed alive because they can reproduce through mitosis, which is an asexual form of reproduction. Despite being unicellular, they demonstrate key characteristics of life. Their reproduction does not involve genetic diversity like sexual reproduction involving meiosis does.
Step-by-step explanation:
The student is correct; amoebas are alive because they exhibit the characteristics of living organisms, such as reproduction. Even though amoebas are unicellular, they still undergo cellular processes inclusive of reproduction through mitosis, where a single cell splits to form two new cells. This type of reproduction is a form of asexual reproduction and differs from meiosis, which is involved in sexual reproduction and results in genetic diversity. Unicellular organisms like amoebas can be just as alive as multicellular organisms.
In the case of organisms that reproduce asexually through mitosis, the genetic makeup of the offspring cells is identical to the parent cell, because they are essentially a copy of the parent cell. In contrast, organisms that undergo meiosis to reproduce sexually produce offspring that have a combination of genetic material from two different cells, typically from two different parents, leading to genetically unique offspring.