Cell Reproduction Chromosomes Mitosis Meiosis Chromosomes Mitosis Meiosis.
Cytology / Cell Biology Cell Reproduction Mitosis & Meiosis.
-
Upload
bruce-jacobs -
Category
Documents
-
view
244 -
download
3
Transcript of Cytology / Cell Biology Cell Reproduction Mitosis & Meiosis.
Cytology / Cell Biology
Cell Reproduction
Mitosis & Meiosis
Recalling the functions of the Plasma Membrane…
(pre-lab discussion)
In your body, which organs perform the functions of a cell membrane?
• Gas exchange lungs• Nutrients absorption small intestine• Waste excretion kidneys / intestines• Osmotic balance (water & salts) kidneys
In your body, what determines the demand for nutrients and oxygen and the production/supply of wastes?
• Your size & the amount of metabolism happening
S.A./V Ratio and Cell Division(cube lab)
BRRRRR!!!
Compare a cell to an animal:Mouse: large surface area per volume,loses heat quicklyElephant: small surface area per volume,loses heat slowly
Discuss with your partner and summarize in your notes
how the SA/volume ratio limits the size of a cell.
Make sure to refer to the cell membrane and cytoplasm and
explain why.
There once was an egg…
This kind of egg…
Then came the barbarians…or was it the Bears?
They came in huge numbers!
But in the end, there could be only one!
Egg and sperm were happily united in the process of fertilization…
1 set of chromosomes
from dad(23)
1 set of chromosomes
from mom(23)
… and formed a zygote (2n = 46), the first cell of an embryo.
A Sea Urchin Embryo in Cell Division (looks a lot like you ~15 years ago)
Embryonic Development:Cell Migration & Differentiation
Cell migration in
Gastrula
Blastopore
3 Tissue layers:(no memorizing)
1. Ectoderm skin (epidermis), hair, nails, nervous system
2. Mesoderm muscles, bones, circulatory system
3. Endoderm inner lining of digestive tract & lungs, glands
Mitosis & Meiosis in Life Cycle of Organism
Mitosis
Meiosis
Zygote
Fertilization
Happy Birthday!
Growth & Development
+
Gametes made: haploid (n), 1 set of chromosomes; in humans, n = 23 chromosomes
In sexual reproduction, male & female gametes unite
(n + n = 2n)
First cell of new organism is diploid (2n),
2 sets of chromosomes
Cells multiply & differentiate into various tissues
What is it? Cell (nuclear) division in eukaryotic cells that produces copies of a cell (bacteria undergo binary fission, a simpler process)
Cell (nuclear) division in eukaryotic cells that produces cells with half the number of chromosomes of a cell
What type of cell undergoes/uses it?
Where does it occur in the organism?
What type of cell is produced and what is it genetic makeup?
Why is it important?
Cell Reproduction Notes
Mitosis Meiosis
What is it? Cell (nuclear) division in eukaryotic cells that produces copies of a cell (bacteria undergo binary fission, a simpler process)
Cell (nuclear) division in eukaryotic cells that produces cells with half the number of chromosomes of a cell
What type of cell undergoes/uses it?
All somatic (body) cells Cells in gonads (sexual glands)
Where does it occur in the organism?
What type of cell is produced and what is it genetic makeup?
Why is it important?
Cell Reproduction Notes
Mitosis Meiosis
What is it? Cell (nuclear) division in eukaryotic cells that produces copies of a cell (bacteria undergo binary fission, a simpler process)
Cell (nuclear) division in eukaryotic cells that produces cells with half the number of chromosomes of a cell
What type of cell undergoes/uses it?
All somatic (body) cells Cells in gonads (sexual glands)
Where does it occur in the organism?
All tissues Testes in male, ovaries in female
What type of cell is produced and what is it genetic makeup?
Why is it important?
Cell Reproduction Notes
Mitosis Meiosis
What is it? Cell (nuclear) division in eukaryotic cells that produces copies of a cell (bacteria undergo binary fission, a simpler process)
Cell (nuclear) division in eukaryotic cells that produces cells with half the number of chromosomes of a cell
What type of cell undergoes/uses it?
All somatic (body) cells Cells in gonads (sexual glands)
Where does it occur in the organism?
All tissues Testes in male, ovaries in female
What type of cell is produced and what is it genetic makeup?
Daughter cells are identical to each other and mother cell; diploid (2n, 2 sets of chromosomes)
Gametes/sex cells: Spermatozoa/sperm in male, ovum/egg in female; haploid (n, 1 set chromosomes)
Why is it important?
Cell Reproduction Notes
Mitosis Meiosis
What is it? Cell (nuclear) division in eukaryotic cells that produces copies of a cell (bacteria undergo binary fission, a simpler process)
Cell (nuclear) division in eukaryotic cells that produces cells with half the number of chromosomes of a cell
What type of cell undergoes/uses it?
All somatic (body) cells Cells in gonads (sexual glands)
Where does it occur in the organism?
All tissues Testes in male, ovaries in female
What type of cell is produced and what is it genetic makeup?
Daughter cells are identical to each other and mother cell; diploid (2n, 2 sets of chromosomes)
Gametes/sex cells: Spermatozoa/sperm in male, ovum/egg in female; haploid (n, 1 set chromosomes)
Why is it important? Used in growth and repair of tissues
Halves the no. of chromosomes from one generation to the next; sexual recombination genetic diversity in species
Cell Reproduction Notes
Mitosis Meiosis
Binary Fission - Prokaryotes
Period 8 Students:Answer the questions below after completing the
first page of your notes:
1. If you get a skin wound, what type of cell division will be used to replace the damaged cells?
2. Why is it important in this process for the daughter cells to be genetically identical to the mother cell?
3. Are somatic cells haploid or diploid?
4. What type of cell division does NOT happen in your body until puberty? How does this differ from the process used to repair your skin?
5. Why is it important for gametes to be haploid (n)?
6. What is the advantage of sexual reproduction vs. asexual reproduction for a species?
Interphase:
G1 = Gap 1: Daughter cells grow
S = Synthesis: DNA is synthesized / replicated
G2 = Gap 2: Cell prepares for mitosis by making proteins,
ribosomes, mitochondria, etc.
Mitosis = nuclear division (karyokinesis), 4 stages
Cytokinesis = division of cytoplasm (starts in Telophase)
Cells may go into G0 indefintely (nondividing phase); some cells cease division, such as nerve cells.
Cell Cycle
Cell Cycle - Movie Time(leave ppt)
In Interphase, DNA is the form of chromatin, not chromosomes
As the cell prepares for mitosis, the DNA is coiled and packaged into chromosomes;
chromosomes are double-stranded in Prophase because the DNA was replicated in Interphase.
Interphase – “spaghetti bowl” (chromatin),
DNA replication
Prophase/Metaphase – double-stranded chromosomes
Prophase of Mitosis: Replicated (double-stranded) chromosomes condense;
two chromatids are joined at the centromere.
The Phases of Mitosis / Karyokinesisin the African globe lily (Scadoxus katherinae)
Prophase Telophase 2 daughter cells
(cytokinesis finished)
AnaphaseMetaphase
(cytokinesis starts here)Mitosis /
Karyokinesis
Animal Cells in Several Stages of Mitosis
3. Anaphase (centromeres break,
chromosomes pulled to opposite poles)
Late Anaphase or Telophase?
1. Prophase (early)
(DNA condensing / chromosomes
forming)
2. Metaphase
(chromosomes align at equator)
Can you identify the phases of mitosis?
Cytokinesis is starting
4. Telophase (last phase of mitosis - citokinesis starts)
Animal Cells in Cytokinesis (cytoplasm/membrane division)after Mitosis
Cleavage furrow
Onion Root Cells in Several Stages of Mitosis
1. Prophase
(DNA condensing, nuclear envelope disintegrating)
2. Metaphase
(chromosomes align at equator)
3. Anaphase
(chromosomes pulled to
opposite poles)
4. Telophase
(cytokinesis starting,nuclear envelopes (2)
form)
Interphase
(chromatin, nucleolus)
Pole-to-pole fiber,elongates cell for division
Centromere-to-pole fiber,moves chromosome to and from metaphase plate Protein disk that attaches to
kinetochore fibers at centromere
MOVEMENT OF CHROMOSOMES DURING CELL DIVISION* ADD THIS DIAGRAM TO YOUR NOTES *
Summarize & Illustrate(after mitosis lab & w.s.)
• Complete your mitosis notes diagrams using n = 2, 2n = 4
• Use different colors for mom’s and dad’s chromosomes (2 from each parent, one big, one small)
• Label the chromatids, centromere, and kinetochore on one chromosome (prophase)
• Annotate/briefly explain what happens in each phase of mitosis on your diagram
Mitosis Worksheet
A. 4B. 13C. 14D. 15
A. 2B. 7C. 10D. 11E. 16F. 18