9th Grade Biology Review

Which property of water allows it to move upward through a plant’s stem against gravity?

• High heat capacity

• Cohesion and adhesion

• Density anomaly

• Polarity only

Which structure is present in plant cells but not in animal cells?

• Ribosome

• Mitochondrion

• Cell wall

• Cytoskeleton

Which of the following is the primary function of the ribosome?

• DNA replication

• Protein synthesis

• ATP production

• Lipid transport

Which statement best describes the role of enzymes in biological reactions?

• They provide energy for the reaction.

• They change the products of the reaction.

• They lower the activation energy needed.

• They increase the temperature of the reaction.

In cellular respiration, most ATP is produced during which stage?

• Glycolysis

• Krebs cycle

• Electron transport chain

• Fermentation

Which process results in gametes with half the chromosome number of the original cell?

• Mitosis

• Meiosis

• Binary fission

• Budding

If a trait is controlled by a single gene with two alleles, and one allele is dominant, which phenotype will be expressed in a heterozygote?

• Both traits equally

• Only the recessive trait

• Only the dominant trait

• Neither trait

Which molecule carries the genetic code from DNA to the ribosome?

• rRNA

• tRNA

• mRNA

• DNA polymerase

Which type of ecological interaction occurs when two species benefit from the relationship?

• Parasitism

• Commensalism

• Mutualism

• Predation

Which statement best explains why a population’s growth rate decreases as it approaches carrying capacity?

• Competition for limited resources increases.

• Birth rate exceeds death rate.

• Predators decrease.

• Genetic variation increases.