Lecture 4/1

• What prevents cytokinesis from simply happening in plants?

  Cell wall
• What happens during telophase in a plants cell division?

  vesicles from the Golgi congregate at the metaphase, forming a cell plate
• What does vesicles provide when forming the cell plate ?

  Carbohydrates that the cell synthesizes to separate the 2 daughter cells
• How many nucleotide pairs is the average human chromosome?

  133,000,000
• The vast majority of a human chromosome is non-coding DNA that lies between the genes

  True
• How many chromosomes do humans have?

  46
• How many homologous chromosome pairs do humans have?

  23
• If you received chromosome #1 from bio. mother, what other chromosome do you need to complete chromosome pair #1?

  Another Chromosome #1 from bio.father
• How do chromosomes 1-22 differ from eachother?

  1. lenght in bp 2. Different sets of genes c.different bp sequence bp= base pairs
• What is a locus on a chromosome?

  Site on a chromosome where a gene is located
• Do homologous chromosomes have the same gene at every locus and the same allele?

  No, they can have the same gene BUT not necessarily the same allele
• What is the purpose of a typical gene?

  To encode a specific protein which has a specific job in a cell
• Alleles are different versions of a gene

  True
• what differs in Alleles?

  Slight differences in DNA sequence
• Where does meiosis occur in the human body?

  Testes and ovaries
• What does meiosis produce?

  4 haploid cells
• Do Gametes have 1 or 2 set of chromosomes?

  1
• Differences in a replicated chromosome

  C

  A) Replicated chromosome

  B) chromatid

  
• What happens during the S phase in mitosis?

  DNA Replication
• What happens in metaphase in mitosis?

  46 replicated chromosomes line up in the equator
• What happens during anaphase in mitosis?

  46 replicated chromosomes split into 46 chromatids(called unreplicated chromosomes)
• How many genes does the average chromosome contain?

  Slightly more than 1000