If someone puts all their eggs in one basket, they put all their effort or resources into doing one thing so that, if it fails, they have no alternatives left.
1. animal reproductive body consisting of an ovum or embryo together with nutritive and protective envelopes; especially the thin-shelled reproductive body laid by e.g. female birds
2. oval reproductive body of a fowl (especially a hen) used as food
3. one of the two male reproductive glands that produce spermatozoa and secrete androgens;