Unit 3

• What is another name for DNA?

  genome
• What does meiosis produce?

  Gametes (sex cells) with half the number of chromosomes as the parent cell.
• How many cell divisions take place in meiosis?

  4
• What is DNA?

  It carries the genetic information of an organism and the genetic makeup
• What connects with what?

  Adenine - thymine

  cytosine - glutamine
• How are compounds in a DNA held together?

  Hydrogen bonds.
• Each base pair is attached to a sugar that is attached to a phosphate group and this is called nucleotide.
• Describe transcription in protein synthesis.

  The DNA gets unzipped by the RNA polymerase. Then the unzipped DNA is attached with complimentary base pairs from the nucleus. The MRNA is made.
• Describe translation in protein synthesis.

  The MRNA goes into the cytoplasm. The tRNA with complimentary base pairs and amino acids attach. Then with the help of the ribosomes the amino acids get joint and there is a polypeptide chain creating a protein.
• What happens during mutation?

  Change in DNA sequence. that causes there to be a change in characteristic.
• What did Mendel discover?

  The principles of inheritance and the laws of genetics. How the recessive and dominant characteristics work.
• What are the sex chromosomes for men and women?

  Men: XY Women: XX
• Why do we make a pedigree chart?

  To track and analyze the inheritance of traits within a family.
• What is ?

  IAIA = A

  IBIB = B

  IOIO=O

  IAIO = A

  IBIO = B

  IBIA = AB
• What was the human genome project?

  Mapping the entire human genome so that we can understand it.
• What is sexual reproduction?

  The fusion of two gamete nuclei
• What is fertilisation defined as?

  The fusion of gamete nuclei
• What is a gamete?

  A sex cell
• How do gametes differ from normal cells?

  They have half the number of chromosomes
• How many chromosomes do human gametes contain?

  23 chromosomes
• What happens when male and female gametes fuse?

  They form a zygote with 46 chromosomes
• What type of nucleus does a zygote have?

  Diploid nucleus
• What are the advantages and disadvantages of sexual reproduction?

  Advantages:

  • Genetic variation in offspring
  • Adaptation to changing environments

  
  

  Disadvantages:

  • Requires two parents
  • Slower reproduction rate

  
• What is asexual reproduction?

  Production of genetically identical offspring

  
• How does asexual reproduction differ from sexual reproduction?

  It does not involve gametes or fertilisation
• What are clones in the context of asexual reproduction?

  Genetically identical offspring
• How do bacteria reproduce asexually?

  Through binary fission

  
• What are the advantages and disadvantages of asexual reproduction?

  Advantages:

  • Faster reproduction rate
  • Only one parent needed

  
  

  Disadvantages:

  • Lack of genetic variation
  • Vulnerability to environmental changes

  
• What are the key differences between sexual and asexual reproduction?

  • Number of parent organisms
  • Type of cell division required
  • Genetic similarity of offspring
  • Sources of genetic variation
  • Number of offspring produced
  • Time taken to produce offspring

  
• What is the role of meiosis?

  To form gametes in reproductive organs
• Why must the number of chromosomes be halved during gamete formation?

  To prevent double chromosome number at fertilisation
• What type of division is meiosis described as?

  Reduction division
• What is produced at the end of meiosis?

  Four haploid daughter cells

  
• What is the importance of meiosis?

  Increases genetic variation of offspring
• How does meiosis produce genetic variation?

  By forming new combinations of chromosomes
• What is a genome?

  The entire set of genetic material
• What was the human genome project?

  A project to sequence the human genome
• What is a gene?

  A section of DNA coding for amino acids
• How do genes control characteristics?

  By coding for proteins that affect cell functions
• What is DNA?

  Deoxyribonucleic acid