APOMIXIS AND POLYEMBRYONY Flashcards
Some species of ________ and ____, have evolved a special mechanism, to produce seeds without fertilisation, called ____________
Asteraceae, grasses, Apomixis
Apomixis is a form of ________ reproduction that mimics ________ reproduction
Asexual, sexual
In some species, without reduction division ,n/2n egg cell is formed and develops into ____ without fertilisation.
2n , embryo
In ____ and ____ varieties, nucellar cells surrounding embryo sac start dividing, protrude into ________ and develop in embryos.
Citrus, Mango, Embryo sac
In some species of Citrus and Mango, each ovule contains many embryos.
True/false
True
Occurence of more than one embryo in a seed is referred as ___________
Polyembryony
Orange seeds also can have many embryos.
True/false
True
Culivation of hybrids has decreased productivity.
True/false
False
tremendously increased
Hybrid seeds have to be produced once in every 10 years.
True/false
False
every year
Because plants’ progeny of hybrid seeds segregate and do not maintain hybrid characters as during meiosis ( during spore formation) , crossing over will take place b/w chromosomes changing the genetic composition of progeny.
Production of hybrid seeds is cheap and cost of such seeds for farmers becomes cheap.
True / false
False
Costly production, expensive for farmers
To solve the problem related to hybrid seeds, hybrids should be made into ________ , then there is no segregation of characters in progeny and farmers no longer have to buy hybrid seeds every year.
Apomicts
To induce apomixis in hybrid seed industry , research is going on around the world to transfer apomictic genes to hybrid varieties.
True/false
True
