Genetics

• What types of reproduction can some organisms perform?

  Some organisms can reproduce by either sexual or asexual reproduction.
• Why is reproducing important for all organisms?

  It is how they pass on their genes.
• How do cells reproduce asexually?

  Cells reproduce asexually by dividing through mitosis.
• What is the result of mitosis in asexual reproduction?

  It results in two diploid daughter cells that are genetically identical to each other and to the parent cell.
• What is the role of meiosis in sexual reproduction?

  Meiosis produces genetically different haploid gametes.
• What happens at fertilization in sexual reproduction?

  A male gamete fuses with a female gamete to produce a diploid zygote.
• What is the diploid number of chromosomes in humans?

  The diploid number of chromosomes in humans is 46.
• What is the haploid number of chromosomes in humans?

  The haploid number of chromosomes in humans is 23.
• What is the purpose of meiosis in terms of genetic variation?

  Meiosis creates genetic variation by mixing genes from both parents.
• What are the components of a nucleotide in DNA?

  A nucleotide consists of a sugar, a phosphate group, and one base.
• What is the structure of DNA?

  DNA has two strands coiled together in the shape of a double helix.
• Which bases pair together in DNA according to complementary base pairing?

  A pairs with T, and C pairs with G.
• What is a gene?


  A gene is a section of DNA on a chromosome that codes for a particular protein.
• How do you extract DNA from fruit cells?

  1. Mash strawberries and mix with detergent and salt to break down cell membranes.
  2. Filter the mixture to remove insoluble bits.
  3. Add ice-cold ethanol to precipitate the DNA.
• What is the role of salt in DNA extraction from fruit cells?

  Salt helps the DNA stick together.
• Who were awarded the Nobel Prize for their work in determining the structure of DNA?

  Crick, Watson, and Wilkins were awarded the Nobel Prize.
• How does sexual reproduction contribute to evolution?

  It leads to genetic variation, which can result in natural selection and evolution.
• If a haploid gamete of a plant species has 12 chromosomes, how many chromosomes will be in the zygote formed by the fusion of two gametes?

  There will be $24$ chromosomes in the zygote.
• Why do organisms need to find and attract mates in sexual reproduction?

  Finding and attracting mates takes time and energy, which affects the number of offspring produced.
• What is the main disadvantage of asexual reproduction regarding environmental changes?


  The whole population may be affected if the environment changes, as there is no genetic variation.
• How does sexual reproduction create genetic variation?

  It combines genetic information from two parents, resulting in offspring that are genetically different from either parent.
• What is the difference between haploid and diploid cells?

  Haploid cells contain half the number of chromosomes, while diploid cells contain the full set.
• What is a genotype?

  A genotype is the combination of alleles, represented by 2 letters.
• What is a phenotype?


  A phenotype is the effects of alleles on an organism's characteristics.
• What does it mean if an organism is homozygous?

  An organism is homozygous if the two alleles it has are the same.
• What does it mean if an organism is heterozygous?

  An organism is heterozygous if the two alleles it has are different.
• What is a dominant allele?


  A dominant allele is one that can express its characteristic if present on one or both chromosomes in a pair.
• What is a recessive allele?


  A recessive allele is one that expresses its characteristic only if present on both chromosomes in a pair.
• What is the probability of having a child with a dimple if both parents carry the allele?

  The probability is 75%.
• What is the role of DNA in protein synthesis?

  • DNA contains a genetic code that determines which proteins are built.
  • Proteins determine how all the cells in the body function.
• What are proteins made of?

  Proteins are made up of chains of molecules called amino acids.
• How does the order of amino acids in a protein affect its function?

  The order of amino acids gives each protein a specific shape, which determines its function.
• What is a gene?

  A gene is a section of DNA that codes for a particular protein.
• What is a base triplet?

  A base triplet is a sequence of three bases in a gene that codes for an amino acid.
• How are amino acids joined together to make proteins?

  Amino acids are joined together following the order of the bases in the gene.
• What is the triplet code?


  A triplet code is a code based on base triplets that determines the sequence of amino acids in a protein.
• What is the role of non-coding DNA?

  Non-coding DNA does not code for amino acids but can still be involved in protein synthesis.
• What is a mutation?


  A mutation is a rare, random change to an organism's DNA base sequence that can be inherited.
• What is a genetic variant?

  A genetic variant is a different version of a gene produced by a mutation.
• How can a genetic variant affect protein activity?

  A genetic variant may code for a different sequence of amino acids, changing the shape and activity of the final protein.