1. Asexual & Sexual Reproduction

2. Hierarchy: Cells make up tissues Tissues make up organs
Organs make up organ systems
Organ systems make up organisms
***FROM SMALL TO LARGE***

3. Examples
Cells: Perform a specific function- skin cells, brain cells, etc.
Tissues: A group of cells working together for a specific function- nervous tissue, muscle tissue
Organs: A group of tissues working together for a specific function- heart, liver, lungs
Organ Systems: A group of organs working together for a specific function- circulatory system, skeletal system
Organisms: Several organ systems sustaining life for organisms
Specialized Cells
Tissues
Organs
Organ Systems
Organism

4. Scientists Robert Hooke Anton VanLeewenhoek
Discovered cells through a microscope
Called them tiny boxes
Used a microscope to discover single-celled organisms in pond scum.
He called
them
animalcules

5. Scientists Matthias Schleiden Theodor Schwann
Discovered all plant parts had cells in them
Found that all animals are composed of cells

6. Scientists
Rudolf Virchow- Concluded that cells come from other cells

7. Cell Theory
1. All organisms are composed of one or more cells (SCHLEIDEN AND SCHWANN)
2. The cell is the basic unit of life in all living things. (SCHLEIDEN AND SCHWANN)
3. All cells come from other cells. (VIRCHOW)

8. Asexual Reproduction
Type of reproduction in which a new organism is produced from ONE parent and the offspring is identical to the parent.
Occurs in most plants, bacteria, protists, and low invertebrates.
The cells in our body reproduce asexually through a process called mitosis.

9. Asexual Reproduction One parent
Offspring are identical to the parents.
One Parent
Identical Offspring

10. Asexual Reproduction
Advantages – Identical to parent, so will get all good characteristics.
Disadvantages – Identical to parent, so will also get bad characteristics and is less able to adapt to the environment.

11. Asexual Reproduction Types of Asexual Reproduction
Regeneration – organism uses cell division to re-grow body parts.
Example: starfish, salamander

12. Asexual Reproduction Types of Asexual Reproduction
Runners– results in a new plant that is genetically identical to the parent plant (a clone).
Examples: strawberry plant, vegetables, and crops.

13. Asexual Reproduction Types of Asexual Reproduction
Budding – organism that produces a bud that breaks away to live on its own.
Example: hydra

14. Asexual Reproduction Types of Asexual Reproduction
Binary Fission – used by bacteria, an organism whose cells do not contain a nucleus copy then divide into two identical organisms
Example: bacteria

15. Sexual Reproduction Two parents
Offspring are a combination of both parents and are therefore different from each parent.
unique / diverse offspring
Two Parents

16. Sexual Reproduction
Advantages – variety and/or diversity of offspring (color, shape, size, intelligence, ability, etc.), More able to adapt to environmental changes.
Disadvantages – uniqueness, sometimes traits needed for survival are not passed on.

17. Sexual Reproduction Types of Sexual Reproduction
Plants – when the reproductive cells of one plant fertilize (pollinate) the reproductive cells of another plant. This produces seeds that can grow into a new plant.

18. Sexual Reproduction
Animals – when the reproductive cells of one animal
fertilize the
reproductive cells of
another animal. This produces a baby (embryo).

19. Reproduction Processes
Mitosis
Meiosis

20. Mitosis VS. Meiosis produces two identical daughter cells
The cells created from mitosis are diploid or 2n.
produces four genetically different daughter cells
The cells created from meiosis are haploid or n
Diploid (2n) – two of each type of chromosome (in homologous pair – carry the same trait)
Haploid (n) – one of each type of chromosome

21. Human cells have 46 chromosomes….
Diploid
Haploid
Therefore, the diploid number (2n) of chromosomes in humans is 46.
The haploid number (n) of chromosomes in humans is 23.

22. Why does mitosis occur?
To replace other cells that have been damaged or worn out
To allow multicellular organisms to grow
For asexual reproduction
Because they get too big!

23. Why does meiosis occur?
Meiosis results in four cells with half the number of chromosomes so that when the sex cells (sperm and egg) combine, the original or normal number of chromosomes will be restored

24. Where does it occur? Mitosis Meiosis Body cells Sex cells
Ex- Skin Cells
Sex cells
Ex- Egg and Sperm only