NSES Content Standard C 
Life Science: Reproduction and heredity
Grades 5-8, page 157

Reproduction is a characteristic of all living systems; because no individual organism lives forever, reproduction is essential to the continuation of every species. Some organisms reproduce asexually. Other organisms reproduce sexually.

Benchmark 5B The Living Environment: Heredity
Grades 6-8, page 108
In some kinds of organisms, all the genes come from a single parent, whereas in organisms that have sexes, typically half of the genes come from each parent.

Benchmark 6B The Human Organism: Human Development
Grades K-2, page 132
All animals have offspring, usually with two parents involved. People may prevent some animals from producing offspring.

Benchmark 6C The Human Organism: Basic Functions
Grades 9-12, page 138
Reproduction is necessary for the survival of any species. Sexual behavior depends strongly on cultural, personal, and biological factors.