Detailed Solutions 2025-2026
Reviewed Update.
Two types of cell death - Answer apoptosis: programmed cell death
necrosis: cell damage and death
Virus vs bacteria - Answer virus: only active within host cells which they need to reproduce
bacteria: single-celled organisms that produce own energy and can reproduce on their own
DNA base pairing - Answer A-T
G-C
DNA strands held together by... - Answer hydrogen bonds
DNA to protein - Answer DNA encodes the sequence of proteins carried in DNA
Gene - Answer DNA coding (for protein, for trait)
Protein functions - Answer structural support, storage, transport, cellular communications,
movement, and defense against foreign substances
Protein sequence - Answer determines how protein will fold
Protein structure - Answer determines function
Enzyme - Answer enhances rate of chemical reaction in body; catalysts, so not used up in
reaction
Process of DNA to protein - Answer DNA > transcription > RNA > transcription > protein
,determines which genes are expressed
Epigenetics results in - Answer heritable changes in the phenotype without changes to DNA
sequence/structure (genotype)
Can epigenetic modifications be transferred from generation to generation? - Answer YES
Three mechanisms of epigenetics - Answer 1. DNA methylation
2. histone modification
3. micro-RNAs
DNA methylation - Answer adding a methyl group to DNA to switch off the gene
possible connection between DNA methylation of 5 genes and PM 2.5
Histone - Answer protein molecule around which DNA is tightly coiled in chromatin
Histone modification - Answer changes in the structure of histones that make it more or less
likely that a segment of DNA will be transcribed
acetyl group allows for transcription
Epigenetic factor that binds to histone tail - Answer acetyl group; allows for transcription
Micro-RNAs - Answer bind to complementary RNA to prevent translation
Mutation - Answer heritable changes in genetic information
genotype change
Microlesions - Answer base pair substitution
, Change in codon - 3 outcomes - Answer no effect = degenerate code
missense mutation = change amino acid, sometimes function
nonsense mutation = premature termination or splice change
Types of genetic mutations in lecture - Answer microlesions
frameshift mutations
macro lesions
Types of genetic mutations - Answer 1. Deletion
2. Duplication
3. Inversion
4. Insertion
5. Translocation
frameshift mutation - Answer mutation that shifts the "reading" frame of the genetic message
by inserting or deleting a nucleotide
consequences: altered protein, often non-functional
macrolesions - Answer chromosomal aberrations
change in chromosomal structure
change in chromosome number
Cause of chromosomal aberration - Answer effects on mitotic machinery, not DNA
Macrolesion mutation: change in chromosome structure - Answer deletion, duplication,
inversion, translocation -- usually cell death
Macrolesion mutation: change in chromosome number - Answer aneuploidy: increase number
of one+ chromosomes
polyploidy: increase in whole set