Educational diagram illustrating the structure and function of DNA within cells, highlighting its role in protein production and genetic information.

Here is the completed worksheet with answers filled in, followed by a detailed explanation:

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Completed Answers:

What important polymer is located in the nucleus?
DNA

DNA is the instructions for making a cell's proteins.

Genes on chromosomes code for specific proteins in a cell.

DNA is also found in mitochondria and chloroplasts.

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✔ Explanation of Each Answer:

#### 1. *What important polymer is located in the nucleus?* → DNA

- The text explicitly states: “Chromosomes are microscopic, threadlike strands composed of the chemical DNA...” and “It is the DNA in the nucleus that actually controls the cell’s workings.”
- DNA (deoxyribonucleic acid) is a polymer made of nucleotide monomers, and it’s the primary genetic material stored in the nucleus.
- So, the key polymer in the nucleus is DNA.

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#### 2. *______ is the instructions for making a cell’s ______.* → DNA is the instructions for making a cell’s proteins

- The passage says: “DNA controls the production of proteins within the cell.” and “The proteins that will be made for your body are determined by the sequence of DNA in the nucleus.”
- This means DNA contains the genetic code (instructions) that tells the cell how to build proteins — which carry out most functions in the cell.
- Therefore, DNA → instructions → proteins.

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#### 3. *______ on chromosomes code for specific ______ in a cell.* → Genes on chromosomes code for specific proteins

- The text states: “Chromosomes are composed of genes, which is a segment of DNA that codes for a particular protein...”
- A gene is a functional unit of DNA that provides the blueprint for one or more proteins.
- So, genes (on chromosomes) → code for → proteins.

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#### 4. *DNA is also found in ______ and ______.* → mitochondria and chloroplasts

- The passage clearly says: “We now know that DNA is also found in some organelles such as the mitochondria and chloroplasts.”
- Mitochondria (in animal and plant cells) and chloroplasts (in plant cells) have their own small circular DNA, believed to be remnants from ancient symbiotic bacteria (endosymbiotic theory).
- So, these two organelles contain their own DNA.

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🧬 Bonus Context:

- DNA’s structure (double helix) was discovered by James Watson and Francis Crick in 1953, as mentioned at the end.
- The “twisted ladder” analogy refers to the sugar-phosphate backbone (sides) and nitrogenous base pairs (rungs).

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✔ All answers are directly supported by the text provided. This worksheet reinforces foundational concepts of genetics: DNA → genes → proteins → traits, and where DNA is located in the cell.

Let me know if you’d like a diagram or further breakdown!