DNA & Chromosomes
What molecule stores genetic information in cells?
DNA
What process turns the information in DNA into mRNA?
Transcription
What tool is used to predict the probability of inheriting traits from parents?
A Punnett square
What is gene expression?
The process of using DNA to make proteins that produce traits
What enzyme breaks down lactose in milk?
Lactase
What are the four nitrogen bases found in DNA?
Adenine, Thymine, Cytosine, and Guanine (A, T, C, G)
What process converts mRNA into a chain of amino acids?
Translation
What term describes two identical alleles (AA or aa)?
Homozygous
What is a mutation?
A change in the DNA sequence (either coding or non-coding DNA)
What condition occurs when people cannot digest lactose as adults?
Lactose intolerance
What is a gene?
A small section of DNA that codes for a specific protein
Where in the cell does translation happen?
At the ribosome in the cytoplasm
What is the difference between genotype and phenotype?
Genotype is the allele combination; phenotype is the physical trait expressed
What field studies chemical tags that turn genes on or off?
Epigenetics
What evolutionary process favors traits that improve survival and reproduction?
Natural selection
How many chromosomes do humans typically have in most body cells?
46 chromosomes (23 pairs)
What is a codon?
A three-base sequence of mRNA that codes for an amino acid
What type of allele is expressed even when only one copy is present?
Dominant allele
What chemical tag often silences or slows gene expression?
DNA methylation (methyl groups)
What evidence is considered the most accurate for determining common ancestry?
Molecular evidence (DNA or amino acid similarities)
What are homologous chromosomes?
Chromosome pairs that have the same size and same types of genes but may have different alleles
What is the start codon that begins translation?
AUG
The process of _______ makes gametes. How many chromosomes are in human gametes (egg or sperm)?
Meiosis; 23 chromosomes
Why do bone cells and lung cells look different even though they have the same DNA?
Different genes are turned on or off through cell differentiation, due to control regions and epigenetic tags
What is evolutionary mismatch? Share an example.
When traits that were once helpful in ancestral environments cause health problems in modern environments (cancer- BRCA1 mutation helps fertility but increases breast cancer risk)