1. Bradycardia refers to a heart rate that is:

A. Normal (60-100 bpm)
B. Slightly elevated (100-120 bpm)
C. Significantly elevated (>120 bpm)
D. Abnormally slow (<60 bpm)

Correct answer: D

Rationale: The correct answer is D. Bradycardia refers to an abnormally slow heart rate, typically defined as being less than 60 beats per minute (bpm). A heart rate of 60-100 bpm is considered normal, not bradycardia. Choices B and C incorrectly describe elevated heart rates, which are not characteristic of bradycardia. Therefore, option D is the most accurate description of bradycardia as it signifies a heart rate that is slower than normal.

2. The Hardy-Weinberg equilibrium describes a population that is:

A. Undergoing rapid evolution due to strong directional selection.
B. Not evolving and at genetic equilibrium with stable allele frequencies.
C. Experiencing a founder effect leading to a reduction in genetic diversity.
D. Dominated by a single homozygous genotype that eliminates all variation.

Correct answer: B

Rationale: Rationale: The Hardy-Weinberg equilibrium describes a theoretical population in which allele frequencies remain constant from generation to generation, indicating that the population is not evolving. This equilibrium occurs under specific conditions: no mutation, no gene flow, random mating, a large population size, and no natural selection. In this scenario, all genotypes are in proportion to the allele frequencies, and genetic diversity is maintained. Options A, C, and D do not accurately describe a population in Hardy-Weinberg equilibrium. Option A suggests rapid evolution due to strong directional selection, which would disrupt the equilibrium. Option C mentions a founder effect, which can reduce genetic diversity but is not a characteristic of a population in Hardy-Weinberg equilibrium. Option D describes a population dominated by a single homozygous genotype, which also does not align with the genetic diversity seen in a population at Hardy-Weinberg equilibrium.

3. Which type of mutation involves a change in the number of chromosomes?

A. Point mutation
B. Frameshift mutation
C. Missense mutation
D. Aneuploidy

Correct answer: D

Rationale: Rationale: A) Point mutation: Involves a change in a single nucleotide base pair within the DNA sequence. B) Frameshift mutation: Involves the insertion or deletion of nucleotides, causing a shift in the reading frame of the genetic code. C) Missense mutation: Involves a single nucleotide change that results in a codon that codes for a different amino acid. D) Aneuploidy: Involves a change in the number of chromosomes, where an individual may have an extra chromosome (trisomy) or a missing chromosome (monosomy). Aneuploidy can lead to genetic disorders such as Down syndrome (trisomy 21) or Turner syndrome (monosomy X).

4. What type of molecule forms the cell membrane and controls what enters and exits the cell?

A. Proteins
B. Carbohydrates
C. Lipids
D. Nucleic acids

Correct answer: C

Rationale: The correct answer is C: Lipids. The cell membrane is primarily composed of a double layer of lipids called phospholipids. These phospholipids have a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails, which arrange themselves to form a barrier that controls the passage of substances in and out of the cell. While proteins are also present in the cell membrane and play important roles in transport and cell signaling, lipids are the main structural component responsible for the selective permeability of the membrane. Carbohydrates are typically found on the outer surface of the membrane and are involved in cell recognition and communication. Nucleic acids are not a major component of the cell membrane; they are primarily responsible for storing and transmitting genetic information within the cell.

5. What part of speech is the underlined word in the sentence: "He felt a growing sense of unease"?

A. Verb
B. Noun
C. Adjective
D. Adverb

Correct answer: B

Rationale: "Sense" represents a concept or feeling, making it a noun here.

6. What is the process of making copies of DNA called?

A. Transcription
B. Translation
C. Replication
D. DNA repair

Correct answer: C

Rationale: Rationale: A) Transcription is the process of synthesizing RNA from a DNA template. It involves the creation of mRNA molecules from a DNA template. B) Translation is the process of synthesizing proteins from mRNA. During translation, the genetic code carried by mRNA is decoded to produce a specific sequence of amino acids, forming a protein. C) Replication is the process of making copies of DNA. This process occurs before cell division and ensures that each daughter cell receives an identical copy of the genetic material. D) DNA repair is a cellular mechanism that corrects errors in DNA that arise due to various factors such as exposure to mutagens or mistakes during DNA replication. It is essential for maintaining the integrity of the genetic material.