Genetics

• What is mitosis?


  Cell division in which the nucleus divides into nuclei containing the same number of chromosomes
• What is meiosis?


  A type of cell division resulting in four daughter cells with half the number of chromosomes
• How many chromosomes are in an ovum and sperm?


  23 chromosomes
• What is a zygote?


  One sperm fertilizes an ovum to form a cell with 46 chromosomes
• What is a trait?


  A characteristic of an organism often determined genetically
• What is genetics?


  The scientific study of heredity
• What is heredity?


  The passing on of characteristics or traits from one generation to another through DNA
• What is reproduction?


  The creation of offspring by sexual (2 parents) or asexual (1 parent) means
• What is fertilization?


  The process of sperm DNA joining with ovum DNA to form a diploid zygote cell
• What is the structure of DNA?


  DNA is made up of two strands twisted around each other in a double helix
• What are the components of DNA strands?

  Each DNA strand is composed of nucleotides, which are the monomers of DNA
• What is a nucleotide?


  A phosphate group, a sugar molecule, and one of four bases
• What are the four bases in DNA?

  Adenine, Thymine, Cytosine, Guanine
• How do bases pair up in DNA?


  Through complementary base pairing
• How do the bases in DNA form the double helix structure?


  They pair up in a complementary manner
• What is the first step of DNA replication?


  The parent DNA molecule starts to 'unzip' at one end
• What happens during the second step of DNA replication?


  Copying of the DNA molecule has begun with complementary bases attaching in both strands
• What is the final outcome of DNA replication?


  Replication results in two identical strands of DNA
• What is the cell cycle?


  A growing and dividing cell goes through a series of stages
• What does diploid mean?


  The cell has 46 chromosomes, with each pair containing one chromosome from each parent
• What are daughter cells?


  The cells produced as a result of mitosis, identical to each other and the original parent cell
• What is a dominant allele?


  The stronger allele, represented by a capital letter, for example, A
• What is a recessive allele?


  The weaker allele that is overridden when there is a dominant allele
• What are homozygous alleles?


  Identical for the same characteristic, for example, AA or aa
• What are heterozygous alleles?


  Different for the same characteristic, for example, Aa
• What is a Punnett Square?


  A diagram used to predict the outcome of a particular cross or breeding experiment
• What are sex chromosomes for males and females?


  Male: X and Y; Female: X and X
• What are autosomes?


  Non-sex chromosomes
• What are homologous chromosomes?


  Same genes arranged in the same order
• What is a mutation?


  A change in DNA sequence affecting genetic information
• What is a single gene mutation?


  Affects a few bases in DNA
• What is a chromosome structure mutation?


  Affects the structure of one or more chromosomes
• What is embryology?


  Similar embryonic stages suggest evolutionary relationships
• What can mutations cause in terms of genetic conditions?


  Genetic diseases
• How can genetic diseases be classified?


  As dominant or recessive
• What can happen to the alleles for genetic diseases in families?


  They can be passed onto family members
• How can family trees be used in genetics?


  • To determine if a disease is dominant or recessive
  • By analyzing the inheritance patterns of traits
• What does it mean if a pedigree is described as non-informative?


  It lacks critical information needed to reach a decision
• If a trait is recessive, what is possible regarding the parents and their child?


  Two unaffected parents can have an affected child
• If a trait is dominant, what is possible regarding the parents and their child?


  Two affected parents can have an unaffected child