The primary structure of a protein refers to the specific sequence of amino acids in its polypeptide chain.
Correct Answer
True
The primary structure of a protein is defined by the unique linear sequence of its amino acids.
Question 2
Lipids are polymers formed from repeating monomer units called fatty acids and glycerol.
Correct Answer
False
Lipids, such as triglycerides, are composed of fatty acids and glycerol, but they are not considered true polymers because they lack a repeating monomeric unit linked by covalent bonds in a chain.
Question 3
Water's high specific heat capacity is primarily due to the extensive hydrogen bonding between its molecules.
Correct Answer
True
Hydrogen bonds between water molecules require a significant amount of energy to break or form, contributing to water's high specific heat capacity.
Question 4
Enzymes increase the rate of a biochemical reaction by lowering the activation energy required for the reaction to proceed.
Correct Answer
True
Enzymes function as biological catalysts by providing an alternative reaction pathway with a lower activation energy.
Question 5
The rough endoplasmic reticulum is primarily involved in the synthesis of lipids and detoxification of drugs.
Correct Answer
False
The rough endoplasmic reticulum is studded with ribosomes and primarily functions in the synthesis and modification of proteins destined for secretion or insertion into membranes. The smooth endoplasmic reticulum is involved in lipid synthesis and detoxification.
Question 6
Mitochondria contain their own circular DNA and ribosomes, supporting the endosymbiotic theory.
Correct Answer
True
The presence of circular DNA and ribosomes within mitochondria is key evidence supporting their evolutionary origin from free-living prokaryotes through endosymbiosis.
Question 7
During cellular respiration, the majority of ATP is generated during the Krebs cycle through substrate-level phosphorylation.
Correct Answer
False
The majority of ATP during cellular respiration is generated during oxidative phosphorylation (electron transport chain and chemiosmosis), not the Krebs cycle, and primarily through chemiosmosis.
Question 8
The fluid mosaic model describes the cell membrane as a dynamic structure where proteins are embedded within or span a phospholipid bilayer.
Correct Answer
True
The fluid mosaic model accurately depicts the cell membrane as a mosaic of protein molecules drifting in a fluid bilayer of phospholipids.
Question 9
Meiosis results in four genetically identical daughter cells, each with the same number of chromosomes as the parent cell.
Correct Answer
False
Meiosis results in four genetically *different* daughter cells, each with *half* the number of chromosomes (haploid) compared to the diploid parent cell.
Question 10
In a dihybrid cross involving two unlinked genes, a phenotypic ratio of 9:3:3:1 in the F2 generation indicates that both parents were heterozygous for both traits.
Correct Answer
True
The 9:3:3:1 phenotypic ratio is the classic result of a dihybrid cross between two individuals heterozygous for two unlinked genes.
Question 11
Linked genes are located on the same chromosome and tend to be inherited together unless crossing over occurs.
Correct Answer
True
Linked genes are physically located on the same chromosome, causing them to be inherited together more often than not, with crossing over being the mechanism that can separate them.
Question 12
A silent mutation is a type of point mutation that results in a change in the amino acid sequence of a protein.
Correct Answer
False
A silent mutation is a point mutation that *does not* result in a change in the amino acid sequence of a protein, typically due to the redundancy of the genetic code.
Question 13
DNA replication is a conservative process, meaning the original DNA molecule remains intact and an entirely new double helix is synthesized.
Correct Answer
False
DNA replication is a *semiconservative* process, where each new DNA molecule consists of one original strand and one newly synthesized strand.
Question 14
During transcription, RNA polymerase synthesizes an RNA strand complementary to the template strand of DNA.
Correct Answer
True
RNA polymerase reads the DNA template strand and synthesizes a complementary RNA molecule.
Question 15
Introns are non-coding regions of a pre-mRNA transcript that are removed before the mRNA leaves the nucleus for translation.
Correct Answer
True
Introns are excised from the primary RNA transcript, and the remaining exons are spliced together to form the mature mRNA.
Question 16
In eukaryotes, translation occurs in the cytoplasm on ribosomes, while transcription occurs in the nucleus.
Correct Answer
True
In eukaryotic cells, the processes of transcription (DNA to RNA) and translation (RNA to protein) are spatially separated, occurring in the nucleus and cytoplasm, respectively.
Question 17
Genetic drift is the random change in allele frequencies in a population, which has a more significant impact on large populations.
Correct Answer
False
Genetic drift has a *more significant impact on small populations*, where random chance events can lead to larger fluctuations in allele frequencies.
Question 18
Natural selection acts directly on an individual's genotype, favoring the alleles that confer a reproductive advantage.
Correct Answer
False
Natural selection acts directly on an individual's *phenotype* (observable traits), which is the expression of the genotype, and indirectly on the alleles that contribute to that phenotype.
Question 19
Homologous structures, such as the forelimbs of mammals, provide evidence for divergent evolution from a common ancestor.
Correct Answer
True
Homologous structures share a common anatomical origin but may have different functions, indicating their divergence from a common ancestral form.
Question 20
The Hardy-Weinberg principle describes a population that is evolving, showing changes in allele and genotype frequencies over time.
Correct Answer
False
The Hardy-Weinberg principle describes a population that is *not evolving* (is in equilibrium), meaning allele and genotype frequencies remain constant from generation to generation under specific conditions.
Question 21
In most terrestrial ecosystems, the biomass of primary consumers is generally greater than the biomass of primary producers.
Correct Answer
False
In most terrestrial ecosystems, the biomass of primary producers (e.g., plants) is significantly *greater* than the biomass of primary consumers (herbivores), reflecting the energy transfer inefficiency between trophic levels.
Question 22
Pioneer species are the first organisms to colonize a barren or disturbed habitat, initiating ecological succession.
Correct Answer
True
Pioneer species are characterized by their ability to establish themselves in harsh, newly available environments, thereby beginning the process of ecological succession.