Genetics

• What are the threadlike structures formed from DNA in the nucleus of a cell called?

  Chromosomes
• How many pairs of chromosomes are needed to build a new organism?

  23 pairs of chromosomes
• What is a gene?

  A small section of a chromosome containing information for a particular characteristic
• What does the term 'genome' refer to?

  The entire DNA of an organism, including all its genes
• What are alternative forms of genes called?

  Alleles
• What is the genotype?

  The genetic make-up represented by a combination of alleles
• What does phenotype refer to?

  The observable physical characteristics resulting from a gene's action
• How do organisms inherit their chromosomes?

  Each pair of chromosomes comes from one parent, one from the mother and one from the father
• What type of cells contain two sets of chromosomes?

  All body cells except sex cells (gametes)
• What are gametes?

  Cells produced by an organism that contain only one set of chromosomes
• What is the process of fertilization?

  The fusion of haploid gametes to form a zygote
• What is the significance of meiosis in gamete formation?

  It reduces the number of chromosomes in half
• What is the basic unit of inherited information?

  A gene
• What is the structure of DNA composed of?

  Long strands of subunits called nucleotides
• What are the components of a nucleotide?

  Phosphate group, deoxyribose (sugar), and a base
• What base pairs with adenine in DNA?

  Thymine
• What base pairs with guanine in DNA?

  Cytosine
• What is the significance of complementary base pairing in DNA?

  Adenine pairs with thymine and guanine pairs with cytosine
• What is the structure of DNA described as?

  A double helix
• What does the term 'base pairing rule' refer to?

  The principle that adenine pairs with thymine and guanine pairs with cytosine
• What is the process of DNA replication?

  DNA can replicate itself to pass genetic information to the next generation
• What is the role of mRNA in protein synthesis?

  It carries genetic code from DNA to the ribosome
• What is the genetic code?

  A set of rules to translate genetic material into proteins
• What is a codon?

  A sequence of three nucleotides on the mRNA that codes for a specific amino acid
• What is a mutation?

  A change in the DNA sequence that can affect protein function
• What is the process of transcription?

  It is the process of copying one strand of DNA to create mRNA
• What happens during translation?

  mRNA codons are translated into amino acid sequences to form proteins
• What is the role of tRNA in protein synthesis?

  tRNA brings specific amino acids to the ribosome corresponding to the mRNA codons
• What is the significance of the anticodon on tRNA?

  The anticodon pairs with the corresponding codon on mRNA
• What is the energy source used during protein synthesis?

  ATP
• What is the final structure of a protein?

  A folded and arranged polypeptide chain
• What are the steps of transcription?

  1. An enzyme unwinds the double helix of DNA.
  2. The two strands of DNA are separated for free nucleotides to fit in.
  3. Free nucleotide bases attach to DNA by complementary base pairing rules.
  4. The single mRNA strand moves away from the DNA helix, and another enzyme zips the DNA strands back together.
  5. The single mRNA strand exits the nucleus to enter the cytoplasm.
• What are the steps of translation?

  1. The mRNA enters the ribosome.
  2. tRNA enters the ribosome and brings a specific amino acid corresponding to the mRNA codon.
  3. The tRNA anticodon pairs with the mRNA codon.
  4. Amino acids are linked together to form a polypeptide chain.
  5. The process continues until a stop codon is reached.
• What is the relationship between DNA, mRNA, and proteins?

  • DNA contains the genetic code.
  • mRNA is synthesized from DNA during transcription.
  • mRNA carries the code to the ribosome for protein synthesis.
  • Proteins are formed by translating the mRNA codons into amino acid sequences.
• What are the roles of different types of RNA in protein synthesis?

  • mRNA (messenger RNA): Carries genetic information from DNA to ribosome.
  • tRNA (transfer RNA): Brings specific amino acids to the ribosome based on mRNA codons.
  • rRNA (ribosomal RNA): Forms the core of the ribosome's structure and catalyzes protein synthesis.
• What is the significance of genetic variation in offspring produced by sexual reproduction?

  • Offspring inherit a combination of genes from both parents.
  • Genetic variation leads to diverse traits and characteristics.
  • It enhances adaptability and survival of species.
• What are the implications of mutations in DNA?

  • Mutations can change the DNA sequence.
  • They can lead to changes in amino acids and protein function.
  • Some mutations may have no effect, while others can be harmful or beneficial.
• What is tRNA attached to?

  An amino acid
• What does tRNA do in protein synthesis?

  It brings amino acids to the ribosome
• What is formed from a chain of amino acids?

  A protein