Comparing Asexual and Sexual Reproduction You can see that each type of reproduction has its advantages and disadvantages when you look at each one as a strategy for survival. Species survive by reproducing. The better suited a species is to its environment, the greater its chance of survival.

For single-celled organisms, asexual reproduction is a survival strategy. When conditions are right, the faster they reproduce, the better their chance of survival over other organisms using the same resources. Having offspring that are genetically identical is also an advantage as long as conditions remain favorable. However, a lack of genetic diversity becomes a disadvantage when conditions change in ways that do not fit the characteristics of an organism.

Sexual reproduction is a different type of survival strategy. The process of finding a mate and the growth and development of offspring require more time. However, this can be an advantage for species that live in environments where seasonal changes affect weather conditions and food availability. Sexual reproduction also provides genetic diversity. If an environment changes, some offspring may have the right combination of characteristics needed to survive.

Some organisms reproduce both sexually and asexually. Yeasts, for example, are single-celled eukaryotes that use both strategies. They reproduce asexually most of the time. However, under certain conditions, they enter a sexual phase. The different advantages of each type of reproduction may help to explain why the living world includes organisms that reproduce sexually, those that reproduce asexually, and many organisms that do both.

10.1 Assessment

Review Key Concepts

1. 1. Review Identify two reasons why a cell's growth is limited.

   2. Explain As a cell's size increases, what happens to the ratio of its surface area to its volume?

   3. Applying Concepts Why is a cell's surface area-to-volume ratio important?

2. 1. Review What is asexual reproduction? What is sexual reproduction?

   2. Explain What types of organisms reproduce sexually?

   3. Summarize What are the advantages and disadvantages of both asexual and sexual reproduction?

VISUAL THINKING

3. The formula for finding the surface area of a sphere, such as a baseball or a basketball, is A = 4πr², where r is the radius. The formula for finding the volume of a sphere is V = 4/3πr³.

   1. Calculate Calculate the surface area and the volume of the baseball and the basketball. Then, write the ratio of surface area to volume for each sphere.

   2. Infer If the baseball and basketball were cells, which would possess a larger ratio of area of cell membrane to cell volume?

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