Gene Code Reading Worksheet
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Biology Focus Article
The Code of Life: How Genes Work
Reading Skill Main Idea & Key Details
Family Clues and Genetics
Have you ever noticed that you share features with family members? You might have your mother’s eye color, your father’s smile, or your grandfather’s height. These physical characteristics are called traits. The study of how traits pass from parents to their children is called genetics. Inside almost every cell in your body, an invisible instruction manual guides how you grow, look, and develop.
DNA and Chromosomes
The master molecule carrying your genetic instructions is called DNA. DNA looks like a long, twisted ladder, a shape scientists call a double helix. If you uncoiled the DNA from just one human cell, it would stretch about six feet long. To fit inside tiny cells, DNA is tightly wound into compact packages called chromosomes. Most humans have 46 chromosomes in each body cell. You inherit exactly 23 chromosomes from your mother and 23 chromosomes from your father.
Genes: Individual Recipes
Each chromosome is divided into smaller segments called genes. You can think of your DNA as a huge family cookbook and each gene as a single recipe. One gene holds the recipe for eye pigment. Another gene gives instructions for your natural hair texture or blood type. Humans have about 20,000 to 25,000 different genes that work together to build and maintain the human body.
Inherited vs. Acquired Traits
Not every trait comes from your DNA. Scientists divide traits into two main groups. Inherited traits come directly from your biological parents through DNA, such as your natural eye color, skin tone, or blood type. In contrast, acquired traits are learned skills or changes that happen during your life. Playing the guitar, speaking two languages, or having a scar on your elbow are acquired traits. Your life is shaped both by the genes you inherit and by the environment around you.
Key Terminology Guide
Genetics The study of how traits pass between generations.
DNA The twisted ladder molecule holding instructions.
Gene A segment of DNA that controls a specific trait.
Trait A physical feature or characteristic of an organism.
The Code of Life • Comprehension Check Student Name:
Directions
Read each question carefully. Select the best answer for each item by bubbling the letter. Then, write one direct sentence from the article as your evidence.
1. What is the central idea of the entire article? Main Idea
A DNA and genes provide the instructions that pass inherited traits from parents to offspring.
B Every single trait a person exhibits during their life is determined entirely by DNA.
C Learning musical instruments and languages changes the number of chromosomes in cells.
D Scientists believe humans have only four active recipes in their genetic cookbook.
Text Evidence:
2. According to the text, how many chromosomes does a person inherit from each biological parent? Supporting Detail
A 46 chromosomes from each parent
B 23 chromosomes from each parent
C 6 chromosomes from each parent
D 20,000 chromosomes from each parent
Text Evidence:
3. What is the main idea of the section titled “Genes: Individual Recipes”? Main Idea
A Cooking food can change human genetics over many generations.
B DNA is shaped like a twisted ladder that stretches across a room.
C Genes are specific segments of DNA that each carry instructions for individual traits.
D Human cells only contain genes that control eye color and blood type.
Text Evidence:
4. Based on the passage, which of the following is an example of an acquired trait? Supporting Detail
A Natural eye color
B Biological blood type
C Playing the guitar
D Natural skin tone
Text Evidence:
Genetics Reading & Comprehension Series Standards: CCSS.ELA-LITERACY.RI.9-10.1 • RI.9-10.2
