Name: 
 

LE Genetics Online Review



Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

1. 

The blood of newborn babies is tested to determine the presence of a certain substance. This substance indicates the genetic disorder PKU, which may result in mental retardation. Babies born with this disorder are put on a special diet so that mental retardation will not develop. In this situation, modification of the baby’s diet is an example of how biological research can be used to
A.
change faulty genes
C.
cure a disorder
B.
stimulate immunity
D.
control a disorder
 

2. 

The following diagram represents part of what process?
le_genetics_review_files/i0030000.jpg
A.
gel electrophoresis
C.
amniocentesis
B.
genetic engineering
D.
cell culturing
 

3. 

A change in the order of DNA bases that code for a respiratory protein will most likely cause
A.
the production of a starch that has a similar function
B.
a change in the sequence of amino acids determined by the gene
C.
the release of antibodies by certain cells to correct the error
D.
the digestion of the altered gene by enzymes
 

4. 

Some studies of identical human twins show that their IQ, height, and talents may be different. The best explanation for these differences is that
A.
the environment interacts with genes in the development and expression of inherited traits
B.
heredity and environment have no influence on the expression of phenotypes
C.
the genotype of twins depends on the interaction of diet and hormone control
D.
people are considered identical if at least half their genes are the same
 

5. 

A medical test indicates that a patient has a defective protein. This condition is most likely due to a change in the directions coded in the
A.
number of hydrogen atoms in starch molecules
B.
sequence of inorganic molecules
C.
number of carbon atoms in sugar molecules
D.
sequence of subunits in DNA
 

6. 

A normal bean seedling which had the ability to synthesize chlorophyll did not produce any chlorophyll when grown in soil totally deficient in magnesium salts. Which statement concerning this plant's inability to produce chlorophyll is true?
A.
The lack of magnesium caused a mutation of the gene controlling chlorophyll production.
B.
The production of chlorophyll was influenced by environmental conditions.
C.
The lack of magnesium prevented the plant's roots from absorbing water.
D.
The production of chlorophyll was controlled solely by heredity.
 

7. 

The nucleus is removed from a body cell of one organism and is placed in an egg cell that has had its nucleus removed. This process, which results in the production of organisms that are genetically alike, is known as
A.
cloning
C.
biological adaptation
B.
fertilization
D.
DNA production
 

8. 

Which statement best describes the result of some of the processes involved in genetic engineering?
A.
They alter the arrangement of hereditary material.
B.
They provide energy for mitosis and meiosis.
C.
They are necessary for normal gamete formation.
D.
They reduce variation in organisms that reproduce asexually.
 

9. 

The coded information in a DNA molecule directly determines the formation of
A.
proteins
B.
starches
C.
sugars
D.
fats
 

10. 

The diagram below represents the organization of genetic information within a cell nucleus.
le_genetics_review_files/i0110000.jpg
The circle labeled Z most likely represents
A.
amino acids
B.
chromosomes
C.
vacuoles
D.
molecular bases
 

11. 

Which laboratory procedure has made possible the development of bacteria that can synthesize human insulin?
A.
amniocentesis
C.
chromatography
B.
karyotyping
D.
genetic engineering
 

12. 

Which organic compounds must have their information encoded in DNA for green plants to synthesize the other three compounds?
A.
sugars
B.
starches
C.
fats
D.
proteins
 

13. 

Which is a technique of genetic research in which genetic information is transferred from cells of one organism to cells of another organism?
A.
genetic engineering
C.
amniocentesis
B.
population genetics
D.
chromatography
 

14. 

To separate leaf pigments, a biologist should use
A.
chromatography
C.
an electronic balance
B.
dissection
D.
a dichotomous key
 

15. 

A sudden change in the DNA of a chromosome can usually be passed on to future generations if the change occurs in a
A.
skin cell
B.
sex cell
C.
liver cell
D.
brain cell
 

16. 

Although all the body cells in an animal contain the same hereditary information, they do not all look and function the same way. The cause of this difference is that during differentiation
A.
embryonic cells use different portions of their genetic information
B.
the number of genes increases as embryonic cells move to new locations
C.
embryonic cells delete portions of chromosomes
D.
genes in embryonic body cells mutate rapidly
 

17. 

The diagram below represents a process that occurs within a cell in the human pancreas.
le_genetics_review_files/i0180000.jpg
This process is known as
A.
digestion by enzymes
C.
energy production
B.
protein synthesis
D.
replication of DNA
 

Short Answer
 
 
GENETIC ENGINEERING
   Genetic engineering is a technique used by scientists to combine or splice genetic material from different organisms. Gene splicing involves changing the normal base sequences of DNA by removing a section of DNA and introducing another gene. This technique may involve the use of the bacterium Escherichia coli. This bacterium has one large chromosome and several small plasmids, which are ring-shaped pieces of DNA found in the cytoplasm.
   Genetic engineers have been able to extract plasmids from E. coli. Restriction enzymes are then used to cut the DNA of the plasmid at designated places in the nucleotide sequence. These same enzymes are then used to cut a section of human DNA. This section of human DNA is then placed into the space in the cut DNA of the bacterial plasmid. The human DNA codes for the synthesis of a product such as human growth hormone. The spliced bacterial DNA, which now contains a piece of human DNA, is referred to as a hybrid. This hybridized plasmid is then transplanted into E. coli. When this bacterium reproduces, the hybrid DNA will be replicated. Offspring will possess the ability to synthesize the human growth hormone.
 

18. 

How do genetic engineers remove sections from human DNA for splicing into bacterial DNA?
 

19. 

What is one benefit of gene splicing?
 

20. 

What is a hybrid plasmid?
 

21. 

Explain why it is not necessary to continue splicing the gene for human growth hormone into E. coli once cultures of the bacteria with the spliced gene are established.
 

22. 

What is a bacterial plasmid?
 

23. 

For many years, humans have used a variety of techniques that have influenced the genetic makeup of organisms. These techniques have led to the production of new varieties of organisms that possess characteristics that are useful to humans. Identify one technique presently being used to alter the genetic makeup of an organism, and explain how humans can benefit from this change. Your answer must include at least:
- the name of the technique used to alter the genetic makeup
- a brief description of what is involved in this technique
- one specific example of how this technique has been used
- a statement of how humans have benefited from the production of this new variety of organism
 
 
CLUES ON AGING
   Researchers appear to have found a link between the aging of human cells and a specific human chromosome. The findings may be useful not only to the understanding of aging but also to the study of cancer.
   Normal human cells have a limited lifespan, after which the cells undergo a process called cellular senescence, or aging, which eventually results in a cell's death. But many animal tumor cells grow indefinitely and escape senescence. Scientists describe those cells as "immortal." Normal cells can be made "immortal" by exposure to chemical carcinogens, by the introduction of certain viruses, and by the addition of some genes found in tumors.
   Researchers have developed cells that were hybrids between immortal Syrian hamster cells and normal human fetal lung cells. After a period of time, they found that most of the hybrid cells died. The few hybrid cells that became immortal shared one feature: they had lost copies of the human chromosome number 1. When a copy of human chromosome 1 was introduced into the immortal hybrid cells, they began to show signs of aging.
   The linking of cellular aging to a specific chromosome suggests that aging is genetically programmed.
 

24. 

Using one or more complete sentences, explain why many human tumor cells are described as immortal.
 

25. 

Using one or more complete sentences, describe how the researchers showed the effect of chromosome 1 on aging.
 



 
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