Structure of DNA

The DNA molecule is composed of two strands that coil around each other to form a double helix. Each strand is made up of a sugar-phosphate backbone with nucleotide bases attached to it. The four types of nucleotide bases found in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G).

Function of DNA

DNA contains the genetic instructions that determine the characteristics of an organism. It carries the information needed for an organism to develop, survive, and reproduce. The sequence of nucleotide bases in DNA serves as a code that is used to create proteins and carry out various functions within the cell.

Replication of DNA

Before a cell divides, its DNA needs to be replicated so that each new cell will have a complete set of genetic instructions. This process involves the unwinding of the DNA double helix and the synthesis of new complementary strands based on the original DNA strands.

Study Guide for DNA

What does DNA stand for?
Describe the structure of DNA.
What are the four types of nucleotide bases found in DNA?
What is the function of DNA?
Explain the process of DNA replication.
Why is DNA important for living organisms?

◂Science Worksheets and Study Guides Second Grade. What is science?

Vocabulary/Answer key

What is science?

The resources above cover the following skills:

LIFE SCIENCE

Ecosystems: Interactions, Energy, and Dynamics

Obtain information from literature and other media to illustrate that there are many different kinds of living things and that they exist in different places on land and in water (e.g., woodland, tundra, desert, rainforest, ocean, river).

EARTH AND SPACE SCIENCE

Earth’s Systems

Make observations from media to obtain information about Earth’s events that happen over a short period of time (e.g., tornados, volcanic explosions, earthquakes) or over a time period longer than one can observe (e.g., erosion of rocks, melting of glaciers).

Collect and evaluate data to identify water found on Earth and determine whether it is a solid or a liquid (e.g., glaciers as solid forms of water; oceans, lakes, rivers, streams as liquid forms of water).