Genetics: Cell Nucleus and DNA Structure

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What is the role of DNA ligase in the DNA replication process?

Proofreads the replicated DNA

Joins small fragments of DNA to form a continuous chain (correct)

Removes damaged DNA segments

Separates DNA strands to allow replication

Which of the following accurately describes the genetic code redundancy?

Different amino acids are coded by identical codons

There are multiple codons coding for the same amino acid (correct)

Each amino acid is coded by only one codon

Codons only code for proteins

What is the main difference between RNA and DNA?

RNA is double-stranded while DNA is single-stranded

RNA has uracil instead of thymine and DNA uses uracil (correct)

DNA has 20 types of nucleotides while RNA has 4

RNA does not contain any genetic information

During transcription, what is the role of RNA polymerase in the elongation phase?

Adds RNA nucleotides to the chain (B) Signup and view all the answers

How do frameshift mutations differ from point mutations?

Point mutations involve the insertion or deletion of base pairs (A) Signup and view all the answers

What is the function of tRNA during translation?

Adds amino acids to the peptide chain (D) Signup and view all the answers

Which process results in the synthesis of RNA from a DNA template?

Transcription (A) Signup and view all the answers

How can a missense mutation differ from a nonsense mutation?

Missense mutations lead to premature termination of protein synthesis (D) Signup and view all the answers

Which agent is known to increase the frequency of mutations by altering DNA bases?

Mutagens (A) Signup and view all the answers

What is the main method through which gene expression is controlled?

Transcription (A) Signup and view all the answers

What is the primary function of the inner membrane in the nucleus?

To enclose the nucleus and contain the nucleolus (B) Signup and view all the answers

What is the main function of histone proteins in chromosomes?

To fold and coil DNA into chromosomes (C) Signup and view all the answers

What is the name of the enzyme responsible for adding nucleotides to the new DNA strand during DNA replication?

DNA polymerase (C) Signup and view all the answers

What is the name of the small, dense structure within the nucleus that holds RNA, DNA, and DNA-binding proteins?

Nucleolus (D) Signup and view all the answers

What is the term for the process of DNA wrapping around histone proteins to form a 'beads on a string' appearance?

DNA packing (C) Signup and view all the answers

What is the number of chromosome pairs in a human cell?

23 (D) Signup and view all the answers

Which genetic condition is characterized by food-seeking behaviors after infancy and rapid weight gain between 1 and 6 years of age?

Prader-Willi Syndrome (A) Signup and view all the answers

What is a common symptom of Angelman Syndrome?

Developmental Delay (A) Signup and view all the answers

Which genetic condition is characterized by having an unstable CGG repeat on the long arm of the X chromosome?

Fragile X Syndrome (A) Signup and view all the answers

What is a common feature of Genetic Anticipation Disorders?

Triplet Repeat Expansion (A) Signup and view all the answers

Which of the following is a clinical manifestation of Fragile X Syndrome?

Limitations in Speech (A) Signup and view all the answers

Why is the paternal gene in the Prader-Willi critical region unable to function?

Imprinting (D) Signup and view all the answers

What causes genetic variability during meiosis?

Crossing over (B) Signup and view all the answers

Which disorder is characterized by the presence of two copies of a given chromosome in some gametes?

Down syndrome (A) Signup and view all the answers

In which mode of inheritance are two recessive alleles required to show the disease?

Autosomal Recessive (D) Signup and view all the answers

What is the key feature associated with Turner syndrome?

Primary Amenorrhea (D) Signup and view all the answers

Which genetic event increases genetic variability?

Genetic Recombination (D) Signup and view all the answers

During which phase of the cell cycle does DNA synthesis occur?

S phase (C) Signup and view all the answers

Which phase of mitosis involves the alignment of chromosomes in the middle of the spindle?

Metaphase (C) Signup and view all the answers

What is the most common cause of Down syndrome?

Nondisjunction of oocyte (D) Signup and view all the answers

What is true about haploid cells?

They are gametes (A) Signup and view all the answers

Which law of inheritance states that each reproductive cell carries only one homologous gene?

Mendel's Law of Segregation (A) Signup and view all the answers

What is a common feature in autosomal dominant disorders?

Disease appearing in every generation (C) Signup and view all the answers

Which proteins interact with cell receptors to activate intracellular signaling pathways?

Mitogens (A) Signup and view all the answers

Which phenomenon results in the hereditary transmission of one gene having no effect on another gene?

Independent Assortment (D) Signup and view all the answers

What is the purpose of survival factors in cell growth control?

Suppress apoptosis (B) Signup and view all the answers

Which type of cell contains 23 pairs of chromosomes?

Diploid cell (D) Signup and view all the answers