ILEARN Biology ECA study guide
ILEARN Biology ECA · Work through your exam, one topic at a time.
The ILEARN Biology End-of-Course Assessment (ECA) is Indiana’s summative end-of-course test for high school biology. Students are required to participate upon completion of the high school biology course-whether taken in middle or high school-to fulfill a federal participation requirement. The ECA is part of the ILEARN assessment system, which measures achievement and growth related to Indiana Academic Standards. The Biology ECA is a computer-adaptive test (CAT) based on the Indiana Academic Standards for Science. Topics on this exam: Molecules to Organisms: Structures and Processes, Heredity: Inheritance and Variation of Traits, Biological Evolution: Unity and Diversity, and Ecosystems: Interactions, Energy, and Dynamics. The ILEARN Biology ECA study guide has 4 sections and about 1,274 words.
01Molecules to Organisms: Structures and Processes
Life is built from four macromolecule families: carbohydrates (quick energy and structure), lipids (long-term energy storage, membranes, signaling), proteins (enzymes, transport, structure, signaling), and nucleic acids (information storage and transmission). Cells are the basic unit of structure and function. Prokaryotic cells lack a membrane-bound nucleus; eukaryotic cells compartmentalize processes into organelles. The plasma membrane is selectively permeable, so substances move by diffusion, facilitated diffusion, osmosis, and active transport.
337 words, about 2 min02Heredity: Inheritance and Variation of Traits
DNA stores genetic information in a sequence of nucleotides; genes are segments that code for proteins or RNA. Replication copies DNA before cell division. Transcription makes mRNA from DNA in the nucleus, and translation builds a polypeptide at the ribosome using codons and tRNA. Traits are influenced by genotype and environment.
325 words, about 2 min03Biological Evolution: Unity and Diversity
Evolution is change in allele frequencies in a population over generations. Natural selection acts on existing heritable variation: individuals with traits that improve survival and reproduction in a given environment leave more offspring, so those alleles become more common. Mutation creates new alleles; gene flow moves alleles between populations; genetic drift changes allele frequencies by chance, especially in small populations. Reproductive isolation can lead to speciation.
312 words, about 2 min04Ecosystems: Interactions, Energy, and Dynamics
Ecosystems include living communities and the abiotic environment. Energy flows in one direction, starting with sunlight captured by producers (autotrophs). Consumers occupy trophic levels; decomposers break down dead matter and recycle nutrients. Only about 10% of energy passes to the next trophic level, so food chains are short and top predators are few.
300 words, about 2 min