Exploring the Building Blocks of Life and Energy

What is a point mutation in the context of gene mutations?

• A mutation affecting only one or very few nucleotides in a gene sequence.

• A mutation that occurs at a particular point in an organism's life cycle.

• A mutation that affects the entire chromosome structure.

• A mutation that results in the addition of a new chromosome.

During which stage of the cell cycle does DNA replication occur?

• G1 phase

• S phase

• G2 phase

• M phase

What is the main purpose of photosynthesis?

• To break down glucose and produce ATP.

• To produce oxygen as a byproduct for respiration.

• To convert solar energy into chemical energy stored in glucose.

• To absorb carbon dioxide from the atmosphere.

Which of the following is the correct sequence of events in cellular respiration?

• Glycolysis → Krebs cycle → Electron transport chain

• Krebs cycle → Glycolysis → Electron transport chain

• Electron transport chain → Glycolysis → Krebs cycle

• Krebs cycle → Electron transport chain → Glycolysis

In a food web, which trophic level is primarily responsible for recycling nutrients?

• Primary producers

• Primary consumers

• Secondary consumers

• Decomposers

What is the expected genotypic ratio for a dihybrid cross between two heterozygous parents (AaBb x AaBb)?

• 9:3:3:1

• 3:1

• 1:2:1

• 1:1:1:1

In a Punnett square, what does a capital letter represent?

• A recessive allele

• A dominant allele

• A homozygous genotype

• A heterozygous genotype

What does it mean if an organism is homozygous for a particular gene?

• It has two different alleles for that gene.

• It has two identical alleles for that gene.

• It expresses a trait that is intermediate between two alleles.

• It expresses both alleles simultaneously.

Which of the following is an example of codominance?

• A pink flower resulting from red and white flowering plants.

• A person with type AB blood.

• A white flower becoming red when exposed to sunlight.

• A plant that is tall only if it has two tall alleles.

What is the role of the primary producers in a trophic level?

• They consume other organisms for energy.

• They decompose organic material.

• They produce energy-rich compounds that are later used by other organisms.

• They are the top predators in the food chain.