DNA & Protein Synthesis
Which sequence correctly shows the flow of genetic information?
A. DNA → RNA → Protein
B. RNA → DNA → Protein
C. Protein → DNA → RNA
D. DNA → Protein → RNA
A. DNA → RNA → Protein
Which outcome would most likely occur if a cell failed to replicate its DNA before mitosis?
A. Extra chromosomes in daughter cells
B. Daughter cells with incomplete genetic info
C. Faster mitosis
D. More mutations
B. Daughter cells with incomplete genetic info
Why is biodiversity important for ecosystem stability?
A. Fewer species reduce competition
B. It allows more weather changes
C. It increases the variety of roles organisms fill
D. It reduces food chains
C. It increases the variety of roles organisms fill
A child inherits a gene for brown eyes but has blue eyes. What likely explains this?
A. Mutation during meiosis
B. Codominance
C. Recessive allele expression
D. Nondisjunction
C. Recessive allele expression
Which scenario best shows natural selection?
A. Plants randomly change color
B. Butterflies survive better due to camouflage
C. A mutation in lab occurs with chemicals
D. A bird eats berries
B. Butterflies survive better due to camouflage
What would happen if a mutation altered the start codon in a gene?
A. Transcription would begin earlier
B. Translation would not occur properly
C. Proteins would be longer
D. Nothing would change
B. Translation would not occur properly
What would be the effect of a nonfunctioning checkpoint in the G1 phase of the cell cycle?
A. The cell would skip cytokinesis
B. Cells might enter mitosis with damage
C. DNA replication would stop
D. Mitochondria would duplicate too early
B. Cells might enter mitosis with damage
Which factor would most likely reduce carrying capacity?
A. Increased birth rate
B. Greater food availability
C. Severe drought
D. Migration into the area
C. Severe drought
Why does crossing over increase genetic diversity?
A. It duplicates alleles
B. It mixes alleles between homologous chromosomes
C. It deletes mutations
D. It prevents mitosis
B. It mixes alleles between homologous chromosomes
Why do homologous structures support the theory of evolution?
A. They have the same function in all species
B. They show common ancestry
C. They are randomly formed
D. They mutate often
B. They show common ancestry
How does mRNA ensure the correct amino acid is added during translation?
A. It bonds directly to amino acids
B. It uses codons that pair with anticodons on tRNA
C. It attaches to the nucleus
D. It connects with DNA strands
B. It uses codons that pair with anticodons on tRNA
Compare aerobic and anaerobic respiration in terms of ATP production.
A. Both produce equal ATP
B. Anaerobic produces more
C. Aerobic produces more
D. Anaerobic uses oxygen more efficiently
C. Aerobic produces more
Which is the best example of a carbon sink?
A. The sun
B. A factory
C. A mature forest
D. A paved city
C. A mature forest
Which best explains how environmental factors affect traits?
A. They change the gene sequence
B. They always cause mutations
C. They influence gene expression
D. They stop inheritance
C. They influence gene expression
Which environmental change could lead to speciation?
A. Stable food sources
B. Geographic isolation
C. Shared habitats
D. Decrease in variation
B. Geographic isolation
Which best describes how gene expression can differ in two cells with identical DNA?
A. Different DNA strands are used
B. Proteins are not needed in one cell
C. Different genes are activated in each cell
D. The chromosomes mutate randomly
C. Different genes are activated in each cell
How does the chloroplast structure support its function in photosynthesis?
A. It stores proteins
B. It contains enzymes for digestion
C. It has membranes for energy absorption
D. It pumps out CO₂
C. It has membranes for energy absorption
How does deforestation affect the carbon cycle?
A. It increases oxygen production
B. It reduces atmospheric CO₂
C. It removes carbon-storing organisms
D. It increases chlorophyll
C. It removes carbon-storing organisms
How is a Punnett square helpful?
A. It tracks mutations
B. It shows possible offspring gene combinations
C. It measures chromosome number
D. It clones traits
B. It shows possible offspring gene combinations
How does a trait become more common in a population?
A. It's chosen by humans
B. It appears randomly in all offspring
C. It increases an organism’s fitness
D. It avoids mutation
C. It increases an organism’s fitness
Which component is directly responsible for assembling amino acids into proteins?
A. Nucleus
B. tRNA
C. DNA polymerase
D. Lysosome
B. tRNA
If light-independent reactions in photosynthesis stopped, which product would decrease first?
A. O₂
B. Glucose
C. Water
D. Light energy
B. Glucose
A population of fish declines after an oil spill. What kind of factor is the oil?
A. Biotic and density-independent
B. Abiotic and density-independent
C. Biotic and density-dependent
D. Abiotic and density-dependent
B. Abiotic and density-independent
If both parents are heterozygous for a trait, what’s the chance their child will be homozygous recessive?
A. 0%
B. 25%
C. 50%
D. 75%
B. 25%
A species goes extinct after a rapid climate shift. What factor explains this?
A. The population evolved too fast
B. Gene frequency remained constant
C. Traits did not allow survival in new conditions
D. There were too many mutations
C. Traits did not allow survival in new conditions