1. MITOSIS and ASEXUAL REPRODUCTION

2. Vocabulary
MITOSIS: when the nucleus divides to form two nuclei and the hereditary material duplicates and divides into two identical sets
CYTOKINESIS: when the cytoplasm divides into two parts

3. Forms of DNA
CHROMATIN: small twisted threads of DNA in non-dividing cells
CHROMOSOMES: when chromatin shortens and thickens in dividing cells (humans have 46 chromosomes)
CHROMATIDS: Sister chromatids are when a chromosome replicates and then the two join together to make sister chromatids. A chromatid is just one of them. They are just one chromosome.

4. ASEXUAL REPRODUCTION only one parent no special reproductive cells
involves mitosis and cytokinesis
each offspring has identical hereditary information
little variation in the species
usually rapid and produces large numbers of offspring

5. SEXUAL REPRODUCTION involves special reproductive cells
usually two separate parents (or two sexually different parts from one organism)
produces offspring genetically different from the parents
show combinations of characteristics
ensures survival of the species by making the population more varied

6. ASEXUAL REPRODUCTION IN PLANTS AND ANIMALS ARE SIMILAR EXCEPT:
Animals have centrioles
Plants - do not have centrioles (spindles still form in plants)
Animals – cell membrane pinches in
Plants – cell plate forms across the middle of the cell and joins with the cell wall to divide the cell

7. MITOSIS in a ANIMAL CELL in the nucleus

8. INTERPHASE (end of interphase – just before cell division begins)
The cell’s resting state between mitotic cycles
The cell grows
Each chromosome duplicates (becomes a double chromosome)
Centrioles duplicate

9. PROPHASE Doubled chromosomes become visible (chromatids)
spindle microtubules
PROPHASE
chromatids
centromere
Doubled chromosomes become visible (chromatids)
Chromatids connected at a region called the centromere
Two pairs of centrioles move to opposite poles of the cell
Microtubules extend from centrioles forming asters and a spindle
Some microtubules attach to centromeres of the chromosomes
Doubled chromosomes move toward the equator of the cell
Nuclear membrane and nucleoli disappear

10. METAPHASE Doubled chromosomes line up at the equator
Centromeres divide and doubled chromosomes become separate chromosomes

11. ANAPHASE Duplicate chromosomes move to opposite poles
Microtubules of the spindle help this movement
One complete set of chromosomes are at each pole

12. TELOPHASE Chromosomes reach poles and spindles disappear
two new nuclei
Chromosomes reach poles and spindles disappear
Nuclear membrane forms and nucleoli reappear
Two identical daughter cells are formed

13. MITOSIS in a ANIMAL CELL in the cytoplasm

14. CYTOKINESIS half of the cytoplasm one of the nuclei
In late anaphase and telophase
Pinching in of the cell membrane
Daughter cells receive
half of the cytoplasm
one of the nuclei
half of the cell organelles

15. Now let’s put it all together

17. MITOSIS in a PLANT CELL
Similar process in plant and animal cells except
no centrioles in the plant – but spindles do form
cell membrane does not pinch in due to the rigid cell wall
a cell plate forms across the middle of the cell that divides the cell into two

18. MITOSIS in a PLANT CELL

20. Interphase and Mitotic Cell Division in Animal Cells
Fill in numbers 1 – 15 on the diagrams
centriole pairs
nucleus
nucleolus
chromatin
asters
spindle microtubules
centromeres
chromatids
equatorial plate
poles
sister chromatids
new forming nuclei
pinching in of the nuclear membrane

21. Complete the worksheet on page 7 in your packet

22. BIANARY FISSION (IN AN AMEOBA)
one cell divides into two daughters (no parent left)
one celled organisms (bacteria, protozoa, algae)

23. BUDDING (IN YEAST) parent divides into two unequal cells
new individual buds out of outer surface of parent
may break off or remain on to form a colony
yeast, hydra, sponges, and some worms

24. SPORE FORMATION specialized cells released from parent (large numbers)
has all parts of the cell and grows into new individual
covered by hard outer wall
fungi, algae, protozoa

25. REGENERATION the ability of an organism to regrow lost parts
regeneration power decreased as organism becomes more complex
usually not used for reproduction purposes
hydra, planaria, starfish, earthworm

26. VEGATATIVE REPRODUCTION
when roots, stems, or leaves give rise to a new plant
two kinds
Natural
bulbs (tulips, onions)
corms (gladioli, crocuses)
tubers – large underground stems (potatoes)
runners (stolons) – sideways surface growing stem (strawberries)
rhizomes – sideways underground growing stem (ferns, irises)
2. Artificial
cutting – any part of a plant that is used to produce a new individual

27. advantages to vegetative reproduction:
exact replica
faster growth than from seed
produces fruit faster
gives high yields of fruit and nuts