Understanding Living Things

Cells, Genetics, and Heredity

Harcourt Science

Chapter 1

Mrs. Strand6th grade Lockwood Middle School

Cells, Genetics and Heredity

Terms Cell membrane Cell wall Cytoplasm Mitochondria Chloroplast Vacuole Nucleus Chromosome Nuclear Membrane

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

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

How Plants & Animals Differ

http://www.beyondbooks.com/lif71/4.asp

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

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.

Microscope Parts

1. ____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__________________

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

How Cells Reproduce

Terms Genes Mitosis Meiosis

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.

http://www.agius.com/hew/resource/sens.htm

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

How Cells Reproduce

http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20101/Bio%20101%20Lectures/Biochemistry/biochemi.htm

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.

http://www.alumni.ca/~laued3e/conclusion.html

Mitosis Cell division that

produces new body cells

http://www.dartmouth.edu/~cbbc/courses/bio4/bio4-1997/images/mitosis.JPG

http://www.micro.utexas.edu/courses/levin/bio304/genetics/celldiv.html

Meiosis

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookmeiosis.html

http://www.biologie.uni-hamburg.de/b-online/e09/09b.htm

The process that forms reproductive cells

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

How Traits are Inherited

Terms: Sexual Reproduction Dominant Recessive Punnett Square

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

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)

Punnett Squares

Used for making predictions

Chromosome Theory

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