Question

Compare and contrast the origin (gametophyte generation? sporophyte generation?) and ploidy (1n, 2n, 3n) of the stored food in the seeds of corn, bean and pine.

Answer 1

GAMETOPHYTE GENERATION :- It is the one of alternating phases in the life cycle of plants and algea.It is the sexual phase in the life cycle of plants and algea.The gametophytes of seed plants develop with in the wall of spores that are retained within tissues of the parent sporophyte.These types are Dominant.And reduced,indipendent,photosynthatic,freeliving.It depends on surronding sporophytes tissues for nutrition.

SPOROPHYTE GENERATION:- In sporophyte like mosses and other non vascular plants they are reduced ,dependent on gametophyte for nutrition,while comming to ferns and other seedless vascular plants they are dominant.It is the diploid multicellular stage in the life cycle of plant and algea,It develops from the zygote produced when a haploid egg cell is fertilied by haploid sperms and each sporophyte cell therefor has double set of cromosomes one set from each plant.

PLOIDY:- It is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudosomal genes .Somatic cell,tissues and individual organisms can be discribed according to the number of sets of chromosomes present in the polody level that is monoploid(1 set), dipolid( 2 set), triploid(3 sets), tetraploid(4 sets)...etc