Problem Overview:
The worksheet focuses on understanding chromosomes, genes, and their roles in heredity. The questions provided are based on the information given in the text and the diagram of an animal cell (Figure A). Below is a detailed explanation and solution for each question.
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Section II: Chromosomes and Genes
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Question 1:
"A nucleus contains tiny rod-shaped bodies. What are they called?"
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Explanation: The text states that the nucleus of a cell contains threadlike structures called
chromosomes. These chromosomes are rod-shaped and are responsible for controlling heredity.
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Answer: Chromosomes
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Question 2:
"A chromosome is made up of even smaller bodies. What are they called?"
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Explanation: According to the text, each chromosome is composed of many dark bands, and each band represents a small part of the chromosome called a
gene. Genes are the units of heredity that control inherited traits.
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Answer: Genes
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Question 3:
"How is chromosome, gene, and DNA related?"
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Explanation: This question requires understanding the hierarchical relationship between chromosomes, genes, and DNA:
1.
DNA (Deoxyribonucleic Acid): DNA is the genetic material that carries the instructions for the development, functioning, growth, and reproduction of all known living organisms. It is a long molecule made up of nucleotides.
2.
Gene: A gene is a specific segment of DNA that codes for a particular protein or RNA molecule. Genes are the functional units of heredity and determine traits such as eye color, height, etc.
3.
Chromosome: A chromosome is a structure composed of tightly coiled DNA and proteins (histones). Each chromosome contains many genes. In eukaryotic cells, chromosomes are found in the nucleus and are organized into pairs (one from each parent).
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Relationship Summary:
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DNA is the fundamental building block of genes.
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Genes are segments of DNA that code for specific traits or functions.
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Chromosomes are structures made up of DNA and proteins, containing multiple genes.
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Answer:
- DNA is the genetic material that makes up genes.
- Genes are segments of DNA that control specific traits.
- Chromosomes are structures composed of DNA and proteins, containing many genes.
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Final Answers:
1.
Chromosomes
2.
Genes
3.
DNA is the genetic material that makes up genes. Genes are segments of DNA that control specific traits. Chromosomes are structures composed of DNA and proteins, containing many genes.
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Boxed Final Answer:
\[
\boxed{
\text{1. Chromosomes} \\
\text{2. Genes} \\
\text{3. DNA is the genetic material that makes up genes. Genes are segments of DNA that control specific traits. Chromosomes are structures composed of DNA and proteins, containing many genes.}
}
\]
Parent Tip: Review the logic above to help your child master the concept of genes and chromosomes worksheet.
