B2

• What is phenotype?

  The observable characteristics of an organism
• How many chromosomes are found in a normal human body cell?

  46
• How many pairs chromosomes are found in a normal human body cell?

  23
• Tall (T) plants are dominant to short (t) plants. Two parents plants are crossed, their genotypes are: Tt and Tt. What percentage of the offspring is short?

  25
• Tall (T) plants are dominant to short (t) plants. Two parents plants are crossed, their genotypes are: Tt and Tt. What percentage of the offspring is tall?

  75
• What is a Punnett Square?

  A genetic diagram used to work out the possible genotypes for the offspring produced from parents
• What is inheritance?

  The process by which genetic information is passed on from one generation to the next
• What are genes and chromosomes made of?

  DNA
• What is evolution?

  A change in inherited characteristics of a population over time
• What is the probability of an offspring being female?

  50
• What do plants compete with each other for?

  Light, water, minerals, space
• What is competition?

  Where organisms have to struggle against each other for resources
• What is a genetic disorder?

  Diseases caused by the inheritance of a faulty allele from your parents
• Which type of gamete can have a Y sex chromosome?

  Male
• Is cystic fibrosis a dominant or recessive disease?

  Recessive
• Give two sources of evidence for evolution:

  The fossil record, antibiotic resistance in bacteria
• How does Darwin's theory of evolution occur?

  Natural selection
• What is a symptom of cystic fibrosis?

  Thick mucus in the lungs
• Give 2 disadvantages of asexual reproduction:

  No genetic variation in offspring, harmful genes passed on to all offspring
• What does the term homozygous mean?

  The individual has 2 identical alleles for this gene
• What do animals compete with each other for?

  Food, mates, territory
• What are the gametes in plants?

  Egg + pollen
• Is this homozygous or heterozygous: AA

  Homozygous
• What is conservation?

  Protecting a habitat, ecosystem or species from harm
• What does survival of the fittest mean?

  Organisms with adaptations best suited to their environment which are more likely to survive, reproduce and pass on their genes
• Why is it important to preserve biodiversity?

  Areas with greater biodiversity recover faster from natural disasters
• What type of reproduction does aphids do?

  Asexual
• How many sets of chromosomes does a normal body cell nucleus have?

  2
• What type of reproduction does humans do?

  Sexual
• What is variation?

  The differences in characteristics between organisms
• What chromosomes are males?

  XY
• What chromosomes are female?

  XX
• What organism uses both sexual and asexual reproduction?

  plants
• What is male gamete?

  Sperm
• What is an adaptation?

  A feature that enables an organism to survive
• What is the name of the female gamete?

  Egg
• How many chromosomes does a human gamete have?

  23
• The gene for flower colour in pea plants has 2 alleles: purple and white. The purple allele is represented by R and the white allele by r. What is the homozygous dominant genotype?

  RR
• Does bacteria reproduce asexually or sexually?

  Asexually
• Can some insects reproduce asexually?

  Yes