Download gene technologies in our Lives

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Skills Worksheet
Active Reading
Section: Gene Technologies in Our Lives
Read the passage below. Then answer the questions that follow.
In 1997, a scientist captured worldwide attention when he
announced the first successful cloning using an adult animal. A
lamb named Dolly was cloned from the nucleus of a mammary
(udder) cell taken from an adult sheep. The clone was made using
a process known as somatic-cell nuclear transfer (SCNT). SCNT is
a process in which the nucleus of an egg cell is replaced with the
nucleus of an adult cell.
The SCNT process that produced Dolly consisted of the
following: An electric shock was used to fuse a mammary cell
from one sheep with an egg cell without a nucleus from a different
sheep. The fused cell divided to form an embryo, which was
implanted into a surrogate mother. Dolly was born soon after. She
was genetically identical to the adult sheep from which the
mammary cell was taken.
SKILL: READING EFFECTIVELY
Read each question, and write your answer in the space provided.
1. What occurred in 1997?
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2. Why is the word udder enclosed in parentheses in the second sentence?
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3. What is somatic-cell nuclear transfer (SCNT)?
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Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology
8
Gene Technologies and Human Applications
Name ______________________________ Class ___________________ Date __________________
Active Reading continued
SKILL: SEQUENCING INFORMATION
Study the following steps of SCNT leading to the lamb Dolly. Determine the order
in which the steps took place. Write the number of each step in the space
provided.
_____ 4. The fused cell divided to form an embryo.
_____ 5. A mammary cell and an egg cell without a nucleus were taken from
two different sheep.
_____ 6. Dolly was born.
_____ 7. The embryo was implanted into a surrogate mother.
_____ 8. Electric shock was used to fuse the cells.
In the space provided, write the letter of the phrase that best completes the
statement.
_____ 9. Dolly was genetically identical to the sheep that
a. provided the mammary cell.
b. was the surrogate mother.
c. provided the egg cells.
d. Both (a) and (b)
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology
9
Gene Technologies and Human Applications