1. The nucleus is called the "control center" of the cell because it contains the cell's genetic material (DNA) and directs all cellular activities, including growth, metabolism, and reproduction.
2. A gene is a segment of DNA that contains the instructions for making a specific protein or functional RNA molecule, which determines a particular trait or function in an organism.
3. Chromosomes are located in the nucleus of the cell.
4. DNA can be found in the nucleus (as chromosomes), mitochondria, and, in plant cells, chloroplasts.
5. Gregor Mendel established the structure of DNA through his pioneering work on inheritance in pea plants, laying the foundation for genetics, although the actual double helix structure was discovered later by Watson and Crick.
6. The shape of DNA is a double helix — two strands twisted around each other like a spiral staircase.
7. The DNA ladder rises from the sugar-phosphate backbone, formed by alternating deoxyribose sugars and phosphate groups.
8. The four bases that make up the rungs of the DNA ladder are adenine (A), thymine (T), cytosine (C), and guanine (G).
9. Sugar is bound to phosphate in the DNA backbone via phosphodiester bonds.
10. In DNA, A bonds with T, and G bonds with C.
11. RNA is necessary as a messenger because it carries the genetic instructions from DNA in the nucleus to the ribosomes in the cytoplasm, where proteins are synthesized.
12. Proteins are made in the ribosomes, using mRNA as a template and tRNA to bring amino acids.
13. RNA differs from DNA in three ways: (1) RNA is single-stranded, while DNA is double-stranded; (2) RNA contains the sugar ribose, while DNA contains deoxyribose; (3) RNA uses uracil (U) instead of thymine (T) as a base.
14. Some cells become brain cells and others become skin cells due to gene expression — even though all cells contain the same DNA, different genes are turned on or off in different cell types, directing them to specialize based on their function and location in the body.
15. DNA is called the "Blueprint of Life" because it contains the complete set of instructions needed to build, maintain, and reproduce an organism — just like a blueprint guides the construction of a building.
Parent Tip: Review the logic above to help your child master the concept of the blueprint of life worksheet answers.
