Download Lesson 3 | DNA and Genetics

Name
Date
Class
Content Vocabulary
LESSON 3
DNA and Genetics
Directions: Write the correct term in the boxes to the right of each definition. Then unscramble the letters
in the shaded boxes to spell a seventh term.
DNA
RNA
mutation
transcription
nucleotide
translation
replication
1. a change in the nucleotide
sequence of a gene
2. the copying of DNA
3. carries the code for
making proteins from the
nucleus to the cytoplasm
4. process that makes mRNA
from DNA
5. nitrogen base + a sugar +
a phosphate group
6. organism’s genetic
material
7. When they are unscrambled, the letters from the shaded boxes spell
, the process that uses RNA to make protein.
Genetics
4
Name
Date
School to Home
Class
LESSON 3
DNA and Genetics
Directions: Use your textbook to answer each question or respond to each statement.
1. Chromosomes contain the genetic code that controls inherited traits.
Describe the typical set of human chromosomes in each cell in terms of the number
of chromosomes and explain what each parent contributes to each set.
2. The strands of DNA in chromosomes are shaped like a twisted ladder.
DNA’s shape is due to the nucleotides that form it.
What is a nucleotide, and how does it determine the structure of DNA?
3. The copying of a DNA molecule to make another DNA molecule is called
replication.
What are the steps of replication?
4. Mutation occurs when there is a change in the nucleotide sequence in a gene.
Describe the different types of mutations.
Genetics
53
Name
Date
Class
Key Concept Builder
DNA and Genetics
Key Concept What is DNA?
Directions: On the line before each statement, write T if the statement is true or F if the statement is false.
1. Genetic information is encoded in a molecule called DNA.
2. This molecule is shaped like a twisted ladder, a shape that is called a triple
helix.
3. James Watson and Francis Crick discovered the structure of this molecule after
studying gamma-ray images of the molecule.
4. The sides of the ladder are made from joined molecules called bases.
5. The combination of a nitrogen base, a sugar, and a phosphate group is a unit
called a gene.
6. The base guanine always joins with the base cytosine.
7. An organism’s genes are located in cell structures called chromosomes.
8. The process by which the molecule of heredity makes copies of itself is called
transcription.
9. Most genes encode information for the production of proteins.
Directions: Answer the question on the lines provided.
10. How does DNA replicate itself?
LESSON 3