Some factors that might be relevant would include quantitative-trait loci, the phenotypic variance, the additive genetic variance, and the environmental variance. Just dropping these names (and others) does not really explain anything, unless you say what they are and how they interact to affect the resemblance between parents and offspring.

In reproduction ,both parents transfer equally half the amount of genetic material to their offspring's. So the genes in offsprings are combination of genes of both father and mother. That is why the offspring does not look exactly like one of their parents but more like a mixture of the two which creates resemblance of traits of both father and mother. Some traits are more dominant which cuts off the recessive ones. There are 23 pairs of chromosomes (total 46 chromosomes) in human cell. In reproduction, 23 chromosomes from father and 23 chromosomes from mother are duplicated into the new cell which further develops into a baby after undergoing various cell division mechanisms.

Explanation:

the answer is true!                                          

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals