1. Understanding Living Things
Cells, Genetics, and Heredity
Mrs. Strand
6th grade
Lockwood Middle School
Harcourt Science
Chapter 1

2. Cells, Genetics and Heredity
Terms
Cell membrane
Cell wall
Cytoplasm
Mitochondria
Chloroplast
Vacuole
Nucleus
Chromosome
Nuclear Membrane

3. How Plants & Animal Cells Differ
The discovery of cells
Robert Hooke
One of the first people to see and study the tiny building blocks that made up living things
Gave cells their name, because they looked like small prison cells

4. Cell Theory Cells are the basic building blocks of all living things
Large organisms have more cells that can do different things
All live activities take place in cells
Heart, lungs, kidneys, skin…
New cells are only produced by existing cells

5. How Plants & Animals Differ

6. Nucleus of the cell
DNA
Directs the activity of the cell
Contains the information and instructions about how the cell is built and its job
Is a chemical
Makes up the chromosomes
Nucleus send out instructions in the form of chemicals through tiny openings in the nuclear membrane

7. How do we see all this cool stuff?
In 1590 Zacharias Janssen was given credit for developing the first compound microscope.
A few years late, Anton van Leeuwenhoek developed a lens that could magnify up to 270 times!
Later he was recognized as the first person to observe microbial life.

8. Microscope Parts ____eye piece_______
2. _______eye tube________________
3. _____objective disc___________
4. _____low powered objective____
5. _____ med. powered objective___
6. _____ high powered objective____
7. ______stage_________________
8. _____stage clip______________
9. ____slide_______________________
10. ____light source__________________
14. ___Coarse Adjustment_______
13. ____ ___fine adjustment_____
12. Arm _____________________
11. ____Base__________________

9. Microscope Safety Carry by the base and the arm Check for shorts
Does the light flicker on and off?
When you begin
Clip the slide onto the stage
Check from the side to see where your lenses are
Begin with the 4x at its highest position
focus
Turn the lens disc to the 10x
Focus
Move the lenses up a little bit before advancing to the 40x

10. How Cells Reproduce
Terms
Genes
Mitosis
Meiosis

11. How Cells Reproduce Most living things start out as a single cell.
Not all of these cells develop into the same type of cell.
Most living things do not grow at a constant rate during their life time.
The only way for an organism
to grow is for cell reproduction.

12. How Cells Reproduce DNA is the blueprint for the entire organism.
DNA codes are used only when they are needed
The nucleus contains the chromosomes.
The chromosomes contain the genes
The genes are made of DNA

13. How Cells Reproduce

14. How Cells Reproduce
In humans, there are 46 chromosomes in all. (23 from each parent)
There are 50,000 genes for each chromosome.
Not all of these genes are activated at all times. This is called differentiation.

15. Mitosis Cell division that produces new body cells

16. Meiosis The process that forms reproductive cells

17. Variations in Organisms
Most organisms are multicellular and have genes from both parents.
Due to the combining of cells that went through meiosis
Traits that result from combining genes of parents are: hair & eye color, height, left or right handedness

18. How Traits are Inherited
Terms:
Sexual Reproduction
Dominant
Recessive
Punnett Square

19. George Mendel
First person to show how traits are passed from parents to offspring
Observed pea plants that he grew in his garden
Easy to get
Grew rapidly
Traits were easy to tell apart
Easy to cross different pea plants
Little chance for self pollination

20. Dominant and Recessive Genes
Mendel thought each plant carried two factors for each trait that it showed.
Parents make and pass on only one factor to the offspring.
The offspring receives a factor from each parent and so carries two factors for each trait.
Factors may be the same or different
Factors may be dominant (stronger) or recessive (weaker)

21. Punnett Squares
Used for making predictions

22. Chromosome Theory
Chromosome theory states that factors, which we know are genes, are located on the chromosomes in very specific places.