← Biology syllabus

MassachusettsBiology

Module 3: Genetics and molecular biology

6 dot points across 6 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How is genetic information stored in the structure of DNA, and how is it copied so faithfully before a cell divides?

Describe the structure of DNA as a double helix of nucleotide base pairs and explain how complementary base pairing allows DNA to be copied accurately during replication (MA STE HS-LS1-1, HS-LS3-1, structure and function).
A standard-level answer on DNA structure and replication for the Massachusetts High School Biology MCAS: the double helix, the four bases and complementary pairing, and how DNA is copied accurately before cell division under HS-LS3.
12 min answer →

How does meiosis make sex cells, and how do meiosis and fertilization create genetic variation in offspring?

Explain how meiosis produces gametes with half the chromosome number and how meiosis and fertilization, together with mutation, create genetic variation among offspring (MA STE HS-LS3-2, HS-LS3-3).
A standard-level answer on meiosis for the Massachusetts High School Biology MCAS: how meiosis makes gametes with half the chromosome number, and how meiosis, fertilization, and mutation create genetic variation in offspring under HS-LS3.
12 min answer →

How does a cell divide to make two genetically identical cells, and why does the body need this kind of division?

Describe the cell cycle and mitosis as the process that produces two genetically identical daughter cells, and explain its role in growth, repair, and asexual reproduction (MA STE HS-LS1-4, HS-LS3-2 supporting).
A standard-level answer on mitosis and the cell cycle for the Massachusetts High School Biology MCAS: how a cell copies its DNA and divides into two genetically identical cells, and the role of mitosis in growth, repair, and asexual reproduction under HS-LS1.
11 min answer →

What is a mutation, when does it affect an organism, and how do humans use our understanding of DNA in biotechnology?

Explain what a mutation is, how mutations change proteins and can be harmful, neutral, or beneficial, and describe examples of biotechnology such as selective breeding and genetic engineering (MA STE HS-LS3-2, HS-LS3-3 supporting).
A standard-level answer on mutations and biotechnology for the Massachusetts High School Biology MCAS: what a mutation is, how it changes proteins and can be harmful, neutral, or beneficial, and examples of selective breeding and genetic engineering under HS-LS3.
12 min answer →

How are traits passed from parents to offspring, and how can a Punnett square predict the probability of an outcome?

Use the rules of inheritance, including dominant and recessive alleles, genotype and phenotype, and Punnett squares, to predict the probability of traits in offspring and apply statistical reasoning to genetic crosses (MA STE HS-LS3-3, using mathematics).
A standard-level answer on inheritance for the Massachusetts High School Biology MCAS: dominant and recessive alleles, genotype and phenotype, how to use a Punnett square, and the probability reasoning behind genetic ratios under HS-LS3.
13 min answer →

How does the sequence of bases in a gene direct the building of a protein, and how does this shape an organism's traits?

Explain how a gene's base sequence is transcribed into messenger RNA and translated into a sequence of amino acids, and how this gene-to-protein pathway produces an organism's traits (MA STE HS-LS1-1, HS-LS3-1).
A standard-level answer on protein synthesis for the Massachusetts High School Biology MCAS: transcription of DNA into messenger RNA, translation into amino acids using codons, and how the gene-to-protein pathway produces traits under HS-LS3.
12 min answer →