Tenses Gap Filling Exercise For Class 10

Fill in the blanks with an appropriate tense form.

American biologist Craig Venter, who ……………………. (founded / had founded / has founded) Celera Genomics in 1998 to sequence the human genome, ………………………… (says / is saying / has said) that he ……………………… (built / has built / had built) a synthetic chromosome out of laboratory chemicals. Mycoplasma laboratorium, the chromosome he ……………………….. (created / has created / was creating) is 381 genes long. When transplanted into a living cell, it ………………………… (will take / would take / takes) control of that cell, and become a new life form.

Genome is the blueprint that ………………………. (contains / is containing / has contained) details of what each individual ought to be like. Every cell in the human body contains a copy of the genome. Each human genome contains 23 chromosomes. Each of these chromosomes contains thousands of genes. These genes ………………………. (decide / decided / has decided), for instance, the colour of an individual’s skin, eyes or hair; his/her height; whether he/she is left handed or right handed.

Answers

American biologist Craig Venter, who founded Celera Genomics in 1998 to sequence the human genome, says that he has built a synthetic chromosome out of laboratory chemicals. Mycoplasma laboratorium, the chromosome he created is 381 genes long. When transplanted into a living cell, it will take control of that cell, and become a new life form.

Genome is the blueprint that contains details of what each individual ought to be like. Every cell in the human body contains a copy of the genome. Each human genome contains 23 chromosomes. Each of these chromosomes contains thousands of genes. These genes decide, for instance, the colour of an individual’s skin, eyes or hair; his/her height; whether he/she is left handed or right handed.