Cell Life Cycle and Reproduction

Cell Life Cycle and Reproduction (Mitosis & Meiosis)

Name______assign.#_ __

2. ***Why not just one large cell? Difficult to get ______in and waste out.

10.

11. 4.

19.

24.

BOOK WORK: on your own

Mitosis Review

GA Biology Standards: SB2. Students will analyze how biological traits are passed on to successive generations. b. Explain the role of DNA in storing and transmitting cellular information. e. Compare the advantages of sexual reproduction and asexual reproduction in different situations.

1) The purpose of mitosis is to ensure that:

a) each new cell is genetically different from its parent
b) each new cell receives the proper number of chromosomes

c) gametes are available for reproduction

d) DNA is replicated without errors

2. The image to the right illustrates what phase of mitosis

a) anaphase b) teleophase

c) metaphase d) prophase

3. Which of the following is NOT part of mitosis
a) prophase b) metaphase

c) telophase d) interphase

4. Which of the following is the term used for the "connector" between two sister chromatids?
a) chromosome b) chromatid

c) centromere d) spindle fiber

5. A cell that has 20 chromosomes undergoes mitosis. Which of the following is true?
a) two daughter cells will be created, each have 20 chromosomes

b) two daughter cells will be created, each have 40 chromosomes

c) 4 daughter cells will be created, each having 10 chromosomes

d) 2 daughter cells will be created, each having 10 chromosomes

6. Most cells spend the majority of their time in:
a) prophase b) metaphase

c) interphase d) telophase

7. Cytokinesis begins after which phase?
a) telophase b) prophase

c) anaphase d) metaphase

8. Describe the 2 main purposes of mitosis ______

______

9. How many times does the cell divide during mitosis? ______

10. What kind of cells (somatic or Gametes) are produced at the end of mitosis? ______

11. What are sister chromatids? When are they produced?______

12. Label the cell to the right:

1) Sister Chromatid

2) Spindle Fibers

3) Centromere

4) Centrol

13) Which phase of mitosis is the cell to the right in? ______

14) If a human skin cell goes through mitosis, how many chromosomes will the two new daughter cells have?____

15) If an alligator has 12 chromosomes in a somatic cell, how many will it have after a somatic cell undergoes mitosis? ______

Starter #1:

1. What is the cell cycle…what happens…. what is its purpose?

2. What is mitosis?

3. What kinds of cells go through (or are made during) mitosis?

4. Why do cells go through mitosis?

5. Are the cells diploid or haploid at the beginning of mitosis? At the end?

6. Are the daughter cells genetically identical after mitosis

Notes: Meiosis: Reproduction of Sex Cells

· cells- ______and ______

· Process is called ______

· Similar to Mitosis

· Cell ______

· First division is like mitosis and then the cell divides again to create 4 ______cells.

MEIOSIS = CHROMOSOME REDUCTION DIVISION 31.

· In Humans, starts with ___ and ends up with ____.

· Why? Fertilization creates the ______condition again

· Sperm formation- 4 haploid sperm cells are formed.

· Egg formation-most of the cytoplasm is used in one cell and the other three disintegrate. One haploid egg cell is formed.

37.

Homologous Chromosomes: chromosomes that contain different "versions" of genes for the same traits; one came from mother, its matching homolog came from the father;

39.

40.

Mitosis and Meiosis Summary

Cell division

When a cell divides, its two daughter cells must receive the required number of DNA molecules. In eukaryotes, DNA is sorted into two nuclei in the process of mitosis. A separate process divides the cytoplasm in two. Mitosis is the process in which threadlike nuclear material is divided equally between two daughter cells. Mitosis keeps the number of chromosomes constant from one cell generation to the next. In eukaryotes mitotic cell division is the main process by which growth and tissue repair is accomplished. Mitosis is also the main process by which single-celled and many multi-celled eukaryotes reproduce asexually.

Mitosis

Mitosis can be broken into four phases: prophase, metaphase, anaphase, and telophase. (Continues on next page)

During prophase, the duplicated chromosomes become distinct and spindle fibers radiate across the cell. The nuclear envelope starts to break up.

During metaphase, the duplicated chromosomes line up randomly in the center of the cell between the spindles at the spindle equator.

During anaphase, the duplicated chromosomes are pulled to opposite ends of the cell. Every chromosome that was present in the parent cell is now represented by the daughter chromosome at the poles.

During telophase, a nuclear membrane forms around the chromosomes at each end of the cell. The spindle fibers disappear and the chromosomes disperse and become less distinct. Each nucleus has the same chromosome number as the parent cell. The process of mitosis is now complete.

Cell division produces two new cells, each with the same number of chromosomes as the original cell. These cells are called diploid cells. In humans, the diploid number is 46. Most of your body cells are produced by cell division and contain 46 chromosomes or 23 pairs of homologous (similar) chromosomes

Cytokinesis

At the end of telophase, the cytoplasm begins to divide. In animal cells, the plasma membrane forms a groove and “pinches in” at the middle of the cell. This separates the two new nuclei and splits the cell in half. In plant cells, the rigid cell wall prevents a groove from forming. Instead, a cell plate forms along the center of the cell and cuts the cell in half. The cell plate forms new cell walls. Two daughter cells are formed as a result of cytokinesis. They are identical to their parent cell. Cell division allows unicellular organisms to duplicate themselves in a process called asexual reproduction. In multi-cellular organisms, cell division allows them to grow (i.e., increase the size of the organism), develop from a single cell into a multi-cellular organism, and make other cells to repair and replace worn out cells.

****Questions*****

1. In which phase do the chromosomes line up in the middle?

2. When does the cell actually split?

3. What are the two new cells called?

4. Are the two new cells genetically identical or not?

5. Give 2 reasons why a cell might go through mitosis? (I think this would be a great test question. Don’t you?)

A few cells are produced differently through a process called meiosis. The cells that are produced as a result of meiosis are called gametes or sex cells. The cell divides two times to form 4 cells.

· The first meiotic division produces two cells containing half the number of doublestranded chromosomes.

· The 2nd meiotic division results in the formation of four cells, each containinghalf the number of single-stranded chromosomes.

The prefix hap- means “half” so haploid cells contain only one half of each of the pairs of similar chromosomes. In humans, haploid cells contain 23 chromosomes. These cells are called sperm and egg cells. The following are overviews of sperm and egg formation.

♂ During sperm formation, each primary sperm cell develops into four haploid cells of equal size. As they mature, the cells lose most of their cytoplasm and develop a long whip-like tail used in movement.

♀ During egg formation, each primary egg cell that undergoes meiosis develops into one large haploid cell and three smaller haploid cells called polar bodies. The first meiotic division produces one large cell and the first polar body. After the second meiotic division, the large cell forms an egg cell and another polar body. The first polar body may undergo a second meiotic division to produce two more polar bodies. The polar bodies disintegrate. So what is the advantage of uneven cytokinesis? The final egg cell is provided with a larger supply of stored nutrients.

Mitosis Lab

Name______Assign#______

I. Prepared Slides with microscopes (glass):

“Onion Root Tip” Mitosis: à

Sketch and label at least 2 different cells undergoing Mitosis.

***Give the name of the phase the cells are in.

Animal Cell “Fish Blastula” Mitosis:à

Sketch and label at least 2 different cells undergoing Mitosis.

***Give the name of the phase the cells are in.

Animal Cell “Uterus” Mitosis: (below)

Sketch and label at least 2 different cells undergoing Mitosis.

II. Microslide Viewers: (small black microscopes)-The book that comes with the slides gives you information about each slide.

“Animal Mitosis”

a) Slide #2: Sketch and label the chromosomes. b) Slide #3: Sketch and label the chromosomes

c) Slide #6: Sketch and label the chromosomes. d) Slide #7: Sketch and label the chromosomes.

Post lab questions:

1. Fill in the vinn diagram by comparing and contrasting Mitosis and Meiosis:

Mitosis Meiosis

2. Discuss the reasons why cells go through Mitosis?

3. Discuss the reasons why cells go through Meiosis?

4. What molecules regulate the cell cycle? What happens when the cell cycle is uncontrolled?

5. What is nondisjunction? When does it happen? What does it cause?

Cell Cycle Online

1) Why must a cell divide?

a) Why must cells divide?

Click next and watch the cell.

2) Cell Cycle Video

a) What are the 4 parts of the cycle?

Label them in the rectangles in the circleà

b) What happens during each (be brief)?

Describe under each rectangle. à

c) What controls the cell cycle? What molecules?

d) What can happen if the cell cycled is uncontrolled?

3) Mitosis Video Clip

a) In mitosis a cell reproduces by ______into ____ genetically ______cells.

b) Make a sketch of a cell from each phase. (Hint: pause it when the words come up and draw) Give the name of the phase:

______/ ______/ ______/ ______

c) Are the cells genetically identical after the split? ______

4) Biology in Motion

a) Click “practice mitosis.” Make the cell go through mitosis.

Draw the final 2 cells à.

b) Click “practice meiosis.” Make the cell go through meiosis.

Draw the final 4 cells à.

c) How are mitosis and meiosis different?

5) Meiosis Video

a) Meiosis is the process by which a ______nucleus divides ____ to produce ______nuclei.

b) What are the products of meiosis in animals?

c) When homologous chromosomes exchange pieces of DNA the process is called ______.

d) How is meiosis different from mitosis? ______

______

e) What is the end result of meiosis? ______

6) Mitosis vs. Meiosis

Click through the animation and just watch the cells divide. (You only need to look at the pictures)

1) How are the two processes similar?

2) How are the two processes different?

7) Mitosis Labeling:

Label on the screen, and then label this picture to the right

8) Mitosis Overview labeling

Label on the screen, and then label this picture below

9) Plant Cell Mitosis Labeling

Label on the screen, and then label this picturebelow

10) Meiosis Labeling (below)

Label the diagram correctly. How many points did you get? _____

11) Mitosis animation (Click ‘narrated”)

-Label the diagrams as you go through the animation.

(click on the “Q”. Take the quiz. Write the questions with the correct answer.

1)______

2) ______

3) ______

12) Meiosis Animation. Watch the animation. Click “narrated.” Label the diagram. à

1) How many cell divisions take place? ______

2) Why is one sister chromatid red and the other one blue? ____

3) Are the cells genetically identical at the end? ______

Post 0nline lab questions:

1) What are the two major purposes of mitosis? (why do cells go through this process?)

2) What types of cell are produced during meiosis? Are the cell genetically the same or different?

3) Give two ways mitosis and meiosis are similar?

4) Give two ways that mitosis and meiosis are different?

Starter #3: COMPARING MITOSIS AND MEIOSIS

GA Biology Standards: SB2. Students will analyze how biological traits are passed on to successive generations. b. Explain the role of DNA in storing and transmitting cellular information. e. Compare the advantages of sexual reproduction and asexual reproduction in different situations.