Seed are sometimes sold commercially while still enclosed within the hard wall of the fruit, which must be split open to reach the seed. Different groups of plants have other modifications, the so-called stone fruits (such as the peach) have a hardened fruit layer (the endocarp) fused to and surrounding the actual seed. Nuts are the one-seeded, hard-shelled fruit of some plants with an indehiscent seed, such as an acorn or hazelnut. Seeds are produced in several related groups of plants, and their manner of production distinguishes the angiosperms ("enclosed seeds") from the gymnosperms ("naked seeds"). Angiosperm seeds are produced in
7 Seeds and volume 13 reached number 10. 7 Seeds When astronomers predict that the Earth will be hit by a meteorite, the world leaders meet to develop a plan for human survival called the Seven Seeds project. Each country will cryonically preserve a number of healthy young people, which will allow them to survive the devastation of the impact. After a computer determines that Earth is once again safe for human life, it will revive each group. The Japanese government creates five groups of survivors named Winter, Spring, Summer A, Summer B, and Fall. Each group consists of seven members, who