Cell Reproduction
What is the primary event that occurs during the S phase of the cell cycle?
A) Chromosomes align at the metaphase plate
B) The cell grows and prepares for division
C) DNA is replicated
D) The cell exits the cell cycle and enters G0
C) DNA is replicated
Why did Mendel choose pea plants for his genetic experiments?
A) They have a short generation time and produce many offspring
B) They are easy to cross with other species
C) They have a wide variety of genetic traits that are difficult to track
D) Their genetic makeup is much more complex than other plants
A) They have a short generation time and produce many offspring
Which of the following best describes a heterozygous individual?
A) An individual with two identical alleles for a particular gene
B) An individual with one dominant and one recessive allele for a particular gene
C) An individual with two recessive alleles for a particular gene
D) An individual with two dominant alleles for a particular gene
B) An individual with one dominant and one recessive allele for a particular gene
Which of the following correctly describes the composition of a chromosome?
A) A chromosome consists of a single strand of DNA tightly wound around histone proteins
B) A chromosome consists of two strands of RNA wound around ribosomal proteins
C) A chromosome consists of two strands of DNA wrapped around ribosomal proteins
D) A chromosome consists of DNA, which is wrapped around histone proteins, forming chromatin
D) A chromosome consists of DNA, which is wrapped around histone proteins, forming chromatin
How can cells in your body look and function differently, even though all somatic cells contain the same DNA?
A) Different cells have different numbers of chromosomes
B) Different cells undergo different levels of gene expression due to regulation of transcription and translation
C) Different cells contain different genetic material
D) Different cells have different amounts of DNA
B) Different cells undergo different levels of gene expression due to regulation of transcription and translation
What is the main function of the G1 checkpoint in the cell cycle?
A) To ensure DNA replication occurs properly
B) To assess whether the cell is large enough to divide
C) To prevent damaged DNA from proceeding to mitosis
D) To ensure that sister chromatids are correctly aligned
C) To prevent damaged DNA from proceeding to mitosis
During meiosis I, Mendel’s Law of Independent Assortment is demonstrated when:
A) Homologous chromosomes are separated into different cells randomly
B) Sister chromatids separate into different cells
C) The alleles of one gene are inherited with those of another gene
D) The chromosomes replicate prior to cell division
A) Homologous chromosomes are separated into different cells randomly
In a pedigree, if a trait is seen in every generation and affects both males and females equally, what is the most likely pattern of inheritance?
A) X-linked dominant
B) Autosomal dominant
C) Autosomal recessive
D) X-linked recessive
B) Autosomal dominant
Which type of mutation is most likely to affect protein synthesis?
A) A single base substitution in a non-coding region
B) A frameshift mutation in an exon
C) A silent mutation in an intron
D) A mutation in the 3' untranslated region
B) A frameshift mutation in an exon
Which of the following is a key point in the regulation of gene expression?
A) Gene expression is regulated only after translation occurs
B) Gene expression is regulated primarily at the level of protein folding
C) Gene expression can be regulated at multiple points, including transcription, RNA splicing, and translation
D) Gene expression is not regulated in prokaryotic cells
C) Gene expression can be regulated at multiple points, including transcription, RNA splicing, and translation
Question 3: Which of the following occurs during the M phase of the cell cycle?
A) Chromosomes are replicated
B) The cell grows and prepares for DNA replication
C) The cell divides into two daughter cells
D) DNA is transcribed into mRNA
C) The cell divides into two daughter cells
In a cross between a heterozygous pea plant (Yy) and a homozygous recessive pea plant (yy) for seed color, what is the probability of offspring having yellow seeds?
A) 100%
B) 50%
C) 75%
D) 25%
B) 50%
A child with a rare genetic disorder has one normal allele for a gene (A) and one mutant allele (a) inherited from their mother. The father has the genotype aa. What is the likely inheritance pattern of this disorder?
A) Autosomal dominant
B) Autosomal recessive
C) X-linked dominant
D) X-linked recessive
B) Autosomal recessive
What makes up the backbone of the DNA molecule?
A) Nitrogenous bases bonded together by hydrogen bonds
B) Deoxyribose sugars and phosphate groups
C) Amino acids connected by peptide bonds
D) Ribose sugars and nitrogenous bases
B) Deoxyribose sugars and phosphate groups
Where within the central dogma does the regulation of gene expression most commonly occur?
A) During DNA replication
B) During transcription, when RNA is synthesized from DNA
C) During protein folding after translation
D) During translation, when mRNA is used to build proteins
B) During transcription, when RNA is synthesized from DNA
In which phase of meiosis do homologous chromosomes line up in pairs in the middle, contributing to genetic variation?
A) Prophase I
B) Metaphase I
C) Metaphase II
D) Anaphase I
C) Metaphase II
Which of the following is an example of codominance?
A) Red and white flowers producing pink flowers in F1 generation
B) A person with both AB blood type
C) A person with a single gene affecting multiple traits
D) A gene for color blindness carried on the X chromosome
B) A person with both AB blood type
Non-disjunction during meiosis can lead to the formation of gametes with an abnormal number of chromosomes. Which of the following conditions is most commonly associated with non-disjunction?
A) Down syndrome
B) Cystic fibrosis
C) Huntington's disease
D) Color blindness
A) Down syndrome
What is the directionality of DNA, and how does this affect its replication?
A) DNA is bidirectional and can replicate in both directions from the origin
B) DNA is unidirectional and can only replicate from the 3' to 5' direction
C) DNA is unidirectional, and replication proceeds from the 5' to 3' direction
D) DNA replication occurs in both directions, with leading and lagging strands replicating from the 5' to 3' direction
D) DNA replication occurs in both directions, with leading and lagging strands replicating from the 5' to 3' direction
What is the function of a restriction enzyme in molecular biology?
A) To synthesize RNA from a DNA template
B) To cut DNA at specific sequences, often used in genetic engineering
C) To replicate DNA in the laboratory
D) To package DNA into a protein complex
B) To cut DNA at specific sequences, often used in genetic engineering
Which of the following is true about cancer cells?
A) They always have functional tumor suppressor genes and proto-oncogenes
B) They exhibit uncontrolled division due to mutations that bypass normal cell cycle checkpoints
C) They stop dividing when DNA damage is detected
D) They do not produce telomerase, leading to cell death
B) They exhibit uncontrolled division due to mutations that bypass normal cell cycle checkpoints
Which of the following inheritance patterns is demonstrated by the situation where two genes located on the same chromosome tend to be inherited together?
A) Incomplete dominance
B) Codominance
C) Linked genes
D) Polygenic inheritance
C) Linked genes
What is a karyotype and what can it be used to detect?
A) A diagram of a person’s genetic traits, used to identify dominant and recessive alleles
B) A visual representation of a person’s entire set of chromosomes, used to detect chromosomal abnormalities
C) A list of all the genes in the human genome, used to identify mutations
D) A chart showing the protein expression of different genes in a cell
B) A visual representation of a person’s entire set of chromosomes, used to detect chromosomal abnormalities
Which of the following best describes the central dogma of molecular biology?
A) DNA is transcribed into RNA, which is then translated into protein
B) RNA is transcribed into DNA, which is then translated into protein
C) DNA is replicated into RNA, which is translated into protein
D) Proteins are synthesized directly from DNA without RNA involvement
A) DNA is transcribed into RNA, which is then translated into protein
Which of the following is an application of DNA knowledge used in forensic analysis?
A) Analyzing protein sequences to determine an individual’s genetic disease risk
B) Using PCR to amplify and analyze DNA samples from crime scenes
C) Creating genetically modified organisms (GMOs) for agricultural use
D) Sequencing the entire human genome to track ancestry
B) Using PCR to amplify and analyze DNA samples from crime scenes