Biology

• What does homozygous mean?

  Having two identical alleles for a particular gene.
• What does heterozygous mean?

  Having two different alleles for a particular gene.
• What is a gene?

  A section of DNA which encodes for a specific polypeptide
• What is an allele?

  An allele is a different type of the same gene. e.g. two alleles for eye colour are green and blue (the gene is for eye colour)
• What is a genotype?

  The combination of genes which create the characteristics shown e.g. Dd or ff or GG
• What is a phenotype?


  The characteristics expressed as a result of the genetic makeup e.g. green eyes
• What pair are the sex chromosomes?

  Pair 23
• How many pairs of chromosomes do we have?

  23
• What are the two types of sex chrmosomes?

  X and Y
• What is a genome?


  A genome is the complete set of genetic material (DNA or RNA) present in an organism.
• Where is DNA stored?

  Nucleus
• What is the structure of DNA?

  Double-helix
• What does DNA stand for?

  Deoxyribonucleic acid
• What does RNA stand for?


  Ribonucleic acid
• What process is mRNA used for?

  Transcription
• What process is tRNA used for?

  Translation
• What does tRNA carry?

  Amino Acids
• What is a codon?

  A codon is a sequence of three nucleotides in DNA or RNA that codes for a specific amino acid during protein synthesis.
• What are genes made up of?

  Bases
• What does each base have?

  A complimentary pair
• What do 3 bases code for?

  An Amino Acid
• What are a group of 3 bases called?

  Triplet/codon
• How does transcription work?

  The double helix is untwined and an enzyme splits the two strands apart. Bases in the nucleus rush to pair with the complimetary bases and a mRNA strand is formed. It them leaves the nuleus and goes into the cytoplasm where it find the ribosomes for translation
• How does translation work?

  The mRNA strand goes through the ribosomes where tRNA (with the anticodons to the codons on the mRNA) is called to bind with the mRNA codons and create the amino acids which the mRNA codes for. The amino acids will bind together forming a polypeptide chain (a protein)
• What are the four types of base?

  A,C,T and G
• What base pairs with A?

  T
• What base pairs with G?

  C
• What base pairs with C?

  G
• What base pairs with T?

  A
• What is the base which pairs with A in RNA?

  U
• What is the name for the base A?

  Adenine
• What is the name for the base T?

  Thymine
• What is the name for the base C?

  Cytosine
• What is the name for the base G?

  Guanine
• What is codominance?


  Codominance is a genetic phenomenon where both alleles of a gene are fully expressed in the phenotype of a heterozygous individual.
• What is polygenic inheritance?

  Inheritance of traits controlled by multiple genes.
• How do family pedigrees help find genetic diseases?

  Identifying inheritance patterns.
• What is mitosis?


  Mitosis is the process of cell division in which a single cell divides into two identical daughter cells.
• What is meiosis?

  Meiosis is a type of cell division that produces gametes (sex cells) with half the number of chromosomes as the parent cell. It produces 4 haploid daughter cells
• What does haploid mean?


  Having a single set of chromosomes.