Open Book Test Today!!

Tomorrow we will start on Genetics!!!

Genetics Vocabulary-Thursday

Genetics Notes on Friday

DNA Notes
DNA—a chemical that contains information that an organism needs to grow and function; sometimes called the Blueprint of life.
1. Watson and Crick made an accurate model of DNA in 1953.
2. The structure of DNA is similar to a twisted ladder.
a. The sides of the ladder are made up of sugar-phosphate molecules-(the sugar being dioxyribose)
b. The rungs of the ladder are made up of nitrogen bases-there are 4 nitrogen bases-adenine, guanine, cytosine, thymine–Adenine pairs to Thymine Guanine pairs to Cytosine
3. Before a cell divides, its DNA duplicates itself by unwinding and separating its sides, then forming new sides

Genes—sections of DNA on a chromosome
1. Contain instructions for making specific proteins
2. RNA carries the codes for making proteins from the nucleus to the ribosomes in the cytoplasm.-RNA is similar to DNa except that the sugar that makes DNA is Ribose and the 4 nitrogen bases are uracil, cytocine, adenine, and guanine and it is a ladder with only one side. THerE are 3 types of RNA
a. Messenger RNA carries the code that directs the order in which the amino acids bond.
b. Ribosomal RNA makes up ribosomes, where proteins are built.
c. Transfer RNA brings amino acids to the ribosomes to build the protein.
3. Cells use only the genes that direct the making of proteins needed by that cell.
C. Mutations—any permanent change in the DNA sequence of a cell’s gene or chromosome
1. Can be caused by outside factors like X rays, sunlight, and some chemicals
2. A change in a gene or chromosome can change the traits of an organism.

•http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter12/animations.html

•http://www.sumanasinc.com/webcontent/animations/content/meiosis.html

•http://www.pbs.org/wgbh/nova/baby/divi_flash.html

Definition-

•Cell division by which eggs and sperm are produced.

•The production of sex cells, which are not genetically identical, through a series of cell divisions.

Ensures that humans have the same number of chromosomes in each generation

It is a two-step process that reduces the chromosome number by half—from 46 to 23—to form sperm and egg cells.

This is a reduction in genetic material.

When the sperm and egg cells join at fertilization, each contributes 23 chromosomes so the resulting embryo will have the usual 46

•Interphase: Before meiosis begins, genetic material is duplicated.

•First division of meiosis

–Prophase 1: Duplicated chromatin condenses. Each chromosome consists of two, closely associated sister chromatids. Crossing over can occur during the latter part of this stage.

–Metaphase 1: Homologous chromosomes align at the equatorial plate.

–Anaphase 1: Homologous pairs separate with sister chromatids remaining together.

–Telophase 1: Two daughter cells are formed with each daughter containing only one chromosome of the homologous pair.

•Second division of meiosis: Gamete formation

–Prophase 2: DNA does not replicate.

–Metaphase 2: Chromosomes align at the equatorial plate.

–Anaphase 2: Centromeres divide and sister chromatids migrate separately to each pole.

–Telophase 2: Cell division is complete. Four haploid daughter cells are obtained.

•One parent cell produces four daughter cells. Daughter cells have half the number of chromosomes found in the original parent cell and with crossing over, are genetically different.

Cell Cycle

Interphase

● Growth 1 (G1)

– Growth of cell organelles, chromosomes are stretched out and actively giving directions for proteins

● Synthesis (S)

– Chromosomes are replicated and condensed

– Each chromosome consists of two sister chromatids

     connected by a centromere

● Growth 2 (G2)

– Final growth phase, cell makes sure there are enough organelles for each new cell to split

during cytokinesis-GROW & PREPARE FOR MITOSIS

 MITOSIS

Prophase

(This is the OFFICIAL start of “MITOSIS”)

● Chromosomes condense very tightly and are now visible.

● Spindle fibers form

● Nuclear envelope breaks down

Metaphase

● Sister chromatids line up in middle of cell across “equator”

● Centromere attaches to spindle fiber

Anaphase

● Centromere divides

● Spindle fibers pull chromatids apart

● Chromasomes move to opposite sides of cell

Telophase

● Kinda the reverse of Prophase

● Nuclear envelope reforms

● Chromosomes uncoil

● Spindle fibers break down

Cytokinesis

● Separation of the cytoplasm

● Happens during the process of Anaphase and Telophase

● A little bit different in plants than animals

— Plant cells form a cell plate and animal cells form a cleavage burrow between the two cells where they are going to separate.

Result of Mitosis

● Two new cells with identical DNA (cell directions).

 Which of the following is not a part of the cell theory?

Passive transport requires:

.An animal cell placed in a hypertonic solution (highly concentrated with salt) will_______

 An animal cell placed in a hypotonic solution (less concentration of salt than the cell) will_______

An animal cell placed in isotonic solution (equally concentrated as the cell) will_______

True or False-

Photosynthesis releases energy. 

 C₆H₁₂O₆ and 6O₂ are the result of respiration. 

  Photosynthesis stores energy. 

   Light energy, 6H₂O, and 6CO₂ are at the start of photosynthesis.

     Respiration takes place in the cells of most organisms.

    C₆H₁₂O₆ and 6O₂ are at the start of photosynthesis.

Photosynthesis takes place in cells with chloroplasts.

What is the difference of diffusion and osmosis?

Today you had a writing assignment.  Here is the prompt:  Write about something you have learned in Science.  You also recieved your test review for your Cell test which I moved to Weds.  Tomorrow, we will look over our quizzes from Friday and review for your test!!!

You recieved your Cell Part Quiz back today!!  You will see this information again on your test next Tues!!

Some things that might help you on your quiz tomorrow-

Chemical Equation for Photosynthesis–6CO₂ + H₂O –> C₆H₁₂O₆ + 6O₂

**Be able to write the equation for Cellular Respiration

What are the products of Cellular Respiration?

What are the products of Photosynthesis?

Name 2 reasons why photosynthesis is the most important chemical reaction on earth–1. It  produces oxygen which is needed by all living things  2. We cannot produce our own food, we must get our food/energy from plants.

Yes-You will have a TEST next TUESDAY!!

We finished up our Egg Osmosis Lab Today and took notes over Photosynthesis and Cellular Respiration.

You will be having a quiz TOMORROW!!

Check out this link to see the Egg Osmosis Lab we did in class.

http://c-lab.co.uk/default.aspx?id=9&projectid=56

Lately we have been learning about Diffusion and Osmosis.   Below is the diffusion lab we did in class. 

Diffusion Lab(from http://www.biologycorner.com)

Most chapters follow the cell structure topic with one on the cell membrane and diffusion and osmosis. These concepts can be very difficult for students to understand. In order to give them a view of how diffusion works with a semipermeable membrane, I like to do a lab that uses a plastic bag to model the cell (membrane).

It is a simple lab where students do very little except watch the process and record data and information.   To set it up, you will need plastic bags, iodine, water, and corn starch.  All except iodine are readily available at the supermarket.

Next, take the plastic baggie and add a spoonful of cornstarch and about 100 ml of water.  You don’t even have to be exact.  I like to do at least one of these while the students watch, or you can have the students make them (but be prepared for a mess).   Tie the baggie off and explain to the students that the bag represents a cell, with the cytoplasm being the cornstarch mixture and the plastic is the cell membrane.   Explain that solid objects are not really solid at a molecular level and that the bag is more like a tiny little screen door.  If molecules are small enough, they can pass right through the bag.

With the baggie in place, you will need to prepare enough beakers for your entire class.  Fill them about half full and add several drops of iodine, you want the water to be very orange.  The more concentrated the mixture, the faster the reaction. This is also a good time to point out that iodine is an “INDICATOR” in that it will change color whenever it encounters starch.  You can demonstrate this with a beaker of starch solution and a drop of  iodine.

Students will  carefully place the baggie into the iodine mixture.  Their worksheet will ask them to make some predictions about what will happen and to define diffusion and osmosis.  The process should take about 15 minutes and students should notice a change in the color of the corn starch in the bag.

After 15 Minutes….

Students will then be asked on the worksheet to explain what happened.  A common misconception is that the iodine “ate” through the bag.  Remind students that the bag is like a screen door and iodine is a very small molecule.

Despite the fact that this lab is not very interactive, students do seem to understand the cell model and semi-permeable membranes after completing it.  Many will ask to see what will happen if you put the starch in the beaker and the iodine in the bag.  I’ll set this up and they can view the results the next day.