B6

• What is the full name of DNA?

  Deoxyribonucleic Acid
• What is DNA's primary role in cells?

  It serves as the genetic material.
• What structure is DNA made of?

  Two strands coiled into a double helix.
• How many pairs of chromosomes do humans have?

  23 pairs
• What does the 23rd pair of chromosomes determine?

  It determines a person's sex.
• What are the two types of sex chromosomes?

  XY for male, XX for female.
• What is a gene?

  A small section of DNA on a chromosome.
• What does each gene code for?

  A particular sequence of amino acids.
• How many different amino acids are there?

  20 different amino acids
• What is a genome?

  An organism's entire set of genetic material.
• What has been completed regarding the human genome?

  The complete human genome has been worked out.
• How can identifying genes linked to diseases help us?

  It helps develop effective treatments.
• What can studying tiny differences in genomes help us trace?

  Migration patterns of past human populations.
• What makes up the sugar-phosphate backbone of DNA?

  Phosphate and sugar molecules.
• What are the four bases of DNA?

  A, T, C, G
• What is the relationship between bases on DNA strands?

  Complementary base pairs join strands.
• How is each amino acid coded in DNA?

  By a sequence of three bases.
• What are mutations?

  Changes to the sequence of DNA bases.
• How often do mutations occur?

  Continuously
• What is the effect of most mutations on proteins?

  They have no effect on the protein.
• What happens to proteins synthesized on ribosomes?

  They fold into unique shapes related to function.
• What can mutations in non-coding DNA alter?

  How genes are expressed.
• What are the advantages and disadvantages of asexual reproduction?

  Advantages:

  • Genetically identical offspring
  • Fast reproduction
  • No mate needed

  
  

  Disadvantages:

  • No genetic variation
  • Vulnerable to environmental changes
• What are the advantages and disadvantages of sexual reproduction?

  Advantages:

  • Genetic variation in offspring
  • Increases survival chances

  
  

  Disadvantages:

  • Slower reproduction
  • Requires two parents
• What does meiosis produce?

  Cells with half the normal number of chromosomes.
• What happens during meiosis?

  The cell divides to make four gametes.
• Where are gametes formed?

  In the reproductive organs.
• What restores the normal number of chromosomes in offspring?

  Fertilization of gametes.
• What are the two types of gametes in animals and plants?

  Sperm and egg in animals; pollen and egg in plants.
• What is an allele?

  A version of a gene.
• What is a dominant allele?

  An allele that is always expressed.
• What is a recessive allele?

  An allele expressed only with two copies present.
• What is homozygous?

  Both alleles for a trait are the same.
• What is heterozygous?

  Alleles for a trait are different.
• What is genotype?

  An organism's combination of alleles.
• What is phenotype?

  The characteristics an organism has.
• What is a Punnett square used for?

  • To predict offspring's genotypes
  • To visualize genetic crosses
  • To determine inheritance patterns
• What is the ratio of male to female offspring in a Punnett square for sex determination?

  1:1 ratio
• What is the outcome of a genetic cross between homozygous round and homozygous wrinkly pea plants?

  All offspring have round peas.
• What is the ratio of round to wrinkly offspring from a cross between two heterozygous pea plants?

  3:1 ratio