Question Detail Placenta is the structure formed : by fusion of germ layersby foetus onlyby the union of foetal and uterine tissueby uterine only Answer: Option C Similar Questions : 1. DNA is Deoxyribo Nucleic AcidDouble Nucleic AcidDeoxy Nucleic AcidDeoxyribo Nucleic Alum Answer: Option A 2. Fungi are always ? hetrotrophicsaprophyticautotrophicparasitic Answer: Option A 3. Which blood group is known as Universal donor ? A+A-ABO Answer: Option D 4. Study of factors connected with the improvement of human race ? EvolutionEmbryologyEuthenicsEugenics Answer: Option DExplanation:Evolution - Study of origin of life and formation of new species. Embryology - Study of fertilization of egg, formation of zygote and development of embryo. Euthenics - Study of environmental conditions contributing to improvement of human beings. 5. The richest source of vitamin D is CheeseMilkSpinachCod liver oil Answer: Option D Read more from - Biology Questions Answers