Fill in the blanks with an appropriate verb form. This grammar worksheet is useful for students of classes 9 and 10.

Tenses gap filling worksheet for class 9

Cybrids are human-animal embryos ………………….. (creating / created / create) by using an empty or de-nucleated cow or rabbit cell ………………………. (filled / filling / full) with an adult human cell. The reconstituted one-cell embryo will ………………………… (allow / be allowed / allowing) to develop for a few days in the lab and once it …………………… (becomes / become / had become) a ball of a hundred or so cells, embryonic stem cells ……………………….. (will derive / will be derived / will be deriving) from it to study genetic diseases and the effects of the drugs.

Authorities said the cybrid embryos …………………… (will / would / should) be destroyed within 14 days, ………………………. (forestalling / forestalls / forestalled) the possibility of scientists creating a Frankenstein’s monster or liminal beings which could be both human and animal in form.

Answers

Cybrids are human-animal embryos created by using an empty or de-nucleated cow or rabbit cell filled with an adult human cell. The reconstituted one-cell embryo will be allowed to develop for a few days in the lab and once it becomes a ball of a hundred or so cells, embryonic stem cells will be derived from it to study genetic diseases and the effects of the drugs.

Authorities said the cybrid embryos would be destroyed within 14 days, forestalling the possibility of scientists creating a Frankenstein’s monster or liminal beings which could be both human and animal in form.