Chapter 8 DNA REP & Cell Div Flashcards
Cell division has a role in ________, ________, & __________.
Reproduction, growth, and development.
Cell division produces a ______ supply of ________ cells.
Continuous
Replacement
What are the 4 types of cell division?
Asexual reproduction, sexual reproduction, mitosis and meiosis.
Explain a sexual reproduction.
Replicating genetic material and splitting the contents of one cell into two. Generate identical offspring. Binary fission. (One parent)
Explain sexual reproduction.
Production of a spring from two different parents, offspring genetically different.
What are gametes? And how are those produce?
Sex cells. (sperm and egg cells)
Meiosis
At what point do sex cells (gametes) combine?
At fertilization
What is meiosis?
Division of genetic material that halves the chromosome number and yields genetically variable (different) gametes.
What is mitosis, and when does it begin?
Division of genetic material that yields two genetically identical daughter cells. Begins after fertilization.
Mitotic cell division allow organisms to…
Grow, repair damaged tissue, regenerate body parts (some species), reproduce a sexually (protist).
What is a apoptosis?
Cell death that is a normal part of development. aka: “programmed cell death”
What is the genome?
All genetic material in the cell
What must occur before cell division?
DNA replication, it must duplicate its entire genome
What is a chromosome?
Single molecule of DNA and associated proteins
How many chromosomes does bacteria have? Human?
1 circular and 46
What are the steps to DNA replication?
Enzyme Helicase unwinds and holds DNA apart. hydrogen bonds are broken and DNA polymerase adds new nucleotides complementary to the bases on exposed strand. Hydrogen bonds form between bases (complementary).Ligases form covalent bonds between adjacent DNA segments. The process inns with two identical double-stranded DNA molecules.
What is the job of the enzyme helicase?
Unwind and holds DNA apart
What is the job of the enzyme DNA polymerase?
Copies complementary DNA to both sides, and proofreads. Is incredibly accurate.
What is the job of the enzyme ligase?
Forms covalent bonds between adjacent DNA segments.
What is semi-conservative replication?
Keeping half of the old parent DNA strand into new daughter strands.
If DNA polymerase does not correct a mistake In DNA Replication or a cell is exposed to a mutagen, what can happen?
Mutation (any change in a cell’s DNA sequence)