← Biology syllabus

MassachusettsBiology

Module 5: Evolution and biodiversity

5 dot points across 5 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

What is biodiversity, why does it matter, and how do scientists organize the variety of life?

Explain what biodiversity is and why it matters for ecosystem stability, and describe how organisms are classified into a hierarchy of groups based on shared characteristics and evolutionary relationships (MA STE HS-LS4-5, HS-LS2-7 supporting).
A standard-level answer on biodiversity and classification for the Massachusetts High School Biology MCAS: what biodiversity is, why it supports ecosystem stability, and how organisms are classified into a hierarchy based on shared characteristics and evolutionary relationships under HS-LS4.
11 min answer →

How do biologists show how species are related, and how do you read a phylogenetic tree?

Explain how common ancestry is represented by phylogenetic trees and cladograms, and interpret these diagrams using shared characteristics and molecular data to infer relationships (MA STE HS-LS4-1, patterns).
A standard-level answer on common ancestry and phylogeny for the Massachusetts High School Biology MCAS: how phylogenetic trees and cladograms represent evolutionary relationships, and how to read them using shared characteristics and molecular data under HS-LS4.
11 min answer →

What lines of evidence show that species have evolved over time and share common ancestors?

Describe and evaluate the lines of evidence for evolution, including the fossil record, comparative anatomy (homologous structures), embryology, and molecular biology (DNA and protein similarities) (MA STE HS-LS4-1, engaging in argument from evidence).
A standard-level answer on the evidence for evolution for the Massachusetts High School Biology MCAS: the fossil record, homologous structures, embryology, and molecular (DNA and protein) similarities, and how they support common ancestry under HS-LS4.
12 min answer →

How does natural selection change a population over time, and what conditions are needed for it to happen?

Explain how natural selection acts on heritable variation so that advantageous traits become more common in a population over generations, and apply this to examples such as antibiotic resistance (MA STE HS-LS4-2, HS-LS4-3, cause and effect).
A standard-level answer on natural selection for the Massachusetts High School Biology MCAS: how variation, competition, and differential survival lead to advantageous traits becoming more common over generations, with examples such as antibiotic resistance under HS-LS4.
12 min answer →

How do new species arise, and how do the frequencies of traits in a population change over time?

Explain how reproductive isolation and natural selection can lead to speciation, and describe how the distribution of traits in a population changes as allele frequencies shift over generations (MA STE HS-LS4-3, HS-LS4-4, HS-LS4-5).
A standard-level answer on speciation and population genetics for the Massachusetts High School Biology MCAS: how reproductive isolation and natural selection produce new species, and how allele frequencies and trait distributions change over generations under HS-LS4.
12 min answer →