Lecturer and Coach (School Edu. Dept.) Comp. Ex-situ biodiversity conservation refers to the conservation of species outside their natural habitats. (a) Tissue culture propagation: This involves growing plant tissues in a laboratory, which is a form of ex-situ conservation. (b) Endangered species are protected in their natural habitat: This describes in-situ conservation, not ex- situ. (c) In-vitro fertilization: This technique can be used to assist in the breeding of endangered species in controlled environments, making it an ex-situ method. (d) Cryopreservation of gametes: Storing gametes (sperm and eggs) at very low temperatures is a method to preserve genetic material and is a form of ex-situ conservation.