Ch.2 Cell division
Terms
undefined, object
copy deck
- Mitosis
-
Prophase
Prometaphase
Metaphase
Anaphase
Telophase - Meiosis
- have to do with reproductive cells
- DNA Replication
-
1. DNA helicase enzyme can break H bonds btwn nucleotides along length of molecule.
2. DNA nucleotides now exposed on each chain.
3. DNA polymerase acts to bind free DNA nucleotides to exposed DNA bases of each chain.
4. Covalent bonds btwn sugars & phosphates form
5. Produces 2 DNA molecule each 1/2 old & 1/2 new
6. DNA base sequence is the same in each molecule. - chromosome
- Together, 1 DNA molecule, genetic info, and 1 protein make up a _________.
- 23
- Humans have ___ pairs of chromosomes.
- human genome
- 23 pairs of chromosomes form a ______ ______.
- histones
- Chromosomes that are coiled around a protein within the nucleus.
- Semiconservative
- each new DNA molecule consists of a new strand plus and old strand that functioned as the template for the new strand.
- Mutations
- alteration in DNA can occur
- Proto-oncogenes
-
mutations of genes that control cell growth
can be very dangerous - interphase
-
G0
G1
S
G2 - G0 (interphase)
-
Phase where cell is carrying out its functions that unrelated to cell divdion. Cells that don't undergo cell division, such as skeletal muscle cells, remain in ___ for entire life.
Other cells, such as WBC's, require signal to move from __ to G1. - G1 (interphase)
- Cells starts showing signs of an upcoming cell division, such as an increase in the rate of protein synthesis.
- S (interphase)
- DNA replication occurs, and the chromosomes now exist in pairs. Centrioles duplicate so that they also exist in pairs at the start of cell division.
- G2 (interphase)
-
Rapid protein synthesis continues as the cell grows about twice orginal size.
Cell enters cell division. - interphase and cell division
- The life cycle of a cell can be separated into two main divisions: ________ and ____ _______.
- mitosis and cytokinesis
- Cell division can be divided into two phases:______ and _______.
- Prophase (mitosis)
-
DNA has been replicated and condensed to chromosomes
Centrioles start moving to opposite poles
Chromosomes condense into chromatids
Microtubules disassemble which form mitotic spindles - Chromatid (mitosis)
- A condensed and duplicated state of each individual chromosomes is called a _______.
- Prometaphase (mitosis)
- Nuclear envelope breaks down, centrioles move to the opposite poles of the cell, and mitotic spindle starts to develop btwn the centrioles.
- Metaphase (mitosis)
- Chromosome pairs line up at the mid-line of the cell and attach to mitotic spindle at their centromeres.
- Anaphase (mitosis)
- Sister chromatids of each chromosome pair separate and move along mitotic spindle to opposite poles of the cell.
- Telophase (mitosis)
- Nuclear envelops redevelop, and mitotic spindle breaks down
- Cytokinesis
- Cytoplasm becomes separated and two daughter cells are formed.