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Chapter 10 The Cellular Basis of Inheritance

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Presentation on theme: "Chapter 10 The Cellular Basis of Inheritance"— Presentation transcript:

1 Chapter 10 The Cellular Basis of Inheritance
Cells have distinct phases of growth, reproduction, and normal functions.

2 Objectives Describe the purpose of cell reproduction
Contrast two ways that organisms reproduce

3 All Cells Come From Cells
Where have you heard that before? It is part of the Cell Theory!! Why do organisms need cellular reproduction to occur? Allows living things to repair damage Allows organisms to grow Allows organisms to produce offspring

4 Repair and Growth Did you know that the outer layer of your skin is all dead cells? New cells are continually reproducing underneath and the new cells gradually move upwards to replace dead ones.

5 Close-Up of your skin!!

6 2 Types of Reproduction Sexual Reproduction: Asexual Reproduction:
2 parents Involve gametes (egg & sperm) Genetic material combines Offspring are genetically different from parents Asexual Reproduction: 1 parent The process by which a single cell duplicates its genetic material Offspring identical to parents Examples- Budding & regeneration

7 Types of Asexual Reproduction
Budding Binary Fission Regeneration Spores Vegetative propagation Asexual Reproduction - YouTube

8 Warm Up Match the type of asexual reproduction with its description.
_____ budding A. Small reproductive cells 2. _____ binary fission B. Splitting of cells to make more (bacteria) 3. _____ vegetative propagation C. Re-growing lost parts to form a new organism such as in lizards, starfish, and worms. 4. _____ regeneration D. “runners”/stems of plants that form identical plants. 5. Spores E. A identical organism growing off the side of another until it is able to live on its own.

9 Cell Cycle Objectives Describe the structure of a chromosome (9.2)
Name and Describe the stages of the cell cycle (9.2)

10 The Cell Cycle The cell cycle is a regular pattern of growth, DNA replication, and cell division.

11 Interphase (preparation)
Gap 1 (G1) – cell growth and normal functions Synthesis (S) – DNA Replication = a 2nd copy of the genetic material is made Gap 2 (G2) – additional last minute growth & doubling of organelles Note: Mitosis can ONLY occur if the cell is large enough and the DNA is not damaged by the end of interphase!

12 Mitotic Phase (Mitosis or Meiosis)
Mitosis is the actual nuclear division of the cell. It is composed of 4 major stages: Prophase Metaphase Anaphase Telophase **Cytokinesis = the final splitting of the cytoplasm and “pinching” of the cell membranes.

13 Cells divide at different rates.
The rate of cell division varies with the need for those types of cells.

14 Cell size is limited…Eventually they MUST divide!
S.A / Volume Ratio needs to be high…or diffusion (essential for cell life) suffers!

15 WARM-UP What part of the cell cycle is the “preparation” part?
What part of the cell cycle is the actual splitting of the nucleus?

16 Surface area must allow for adequate exchange of materials.!
Therefore…..Cells that must be large have unique shapes. With a crazy shape, their surface area/volume ratio remains HIGH  and diffusion of materials into/out of them is fast enough to survive!

17 Surface Area vs. Volume of Cells (Relay) GAME 
How the game works: There will be 4 teams. Each team will get a chance to work with each shaped cell. Your team must get the provided molecules (beads) into the nucleus in the shortest amount of time! Only 1 team member can go into the cell at a time and all team members must participate… its a relay!!! Be strategic!!!! Remember your times for the data table! Cell B Cell A

18 DATA TABLE (write time & a team member’s name)
Cell A (long cell in hallway) Cell B (round one in room) AVERAGE TIME

19 WRAP UP What process was represented by the transferring of beads (molecules) into the center (nucleus) of the cells? Which cell went faster? (round or long?) WHY did the above cell go faster? This activity represented that a cells Surface Area/Volume Ratio must be ___________ (high or low) in order for it to be efficient and survive.


21 Cells divide during mitosis and cytokinesis.

22 9 The Cell Cycle in body cells: Mitosis and cytokinesis produce two genetically identical daughter cells.

23 Events that occur During Interphase
(G1) - The cell grows and performs normal functions (S) The DNA is duplicated (via DNA Replication) (G2) The cell undergoes last minute growth & organelle duplication Parent cell centrioles spindle fibers centrosome nucleus with chromatin Interphase Nuclear Envelope

24 Chromatin condenses at the start of mitosis into chromosomes!.
…By having the DNA wrap around proteins. …The end product is chromosomes!!

25 Remember: DNA + proteins is called chromatin.
chromatid telomere centromere Condensed, duplicated chromosome One half of a duplicated chromosome is a chromatid. Sister chromatids are held together at the centromere.

26 Events that occur during Prophase
Chromatin (DNA) condenses and chromosomes are visible spindle fibers form Nuclear envelope disappears Nuclear envelope Breaking apart Sister Chromatids Spindles Forming

27 Events that occur during Metaphase
chromosomes line up in the middle of the cell Spindle fibers attach to centromeres (between sister chromatids) Sister Chromatids Centromere

28 Events that occur during Anaphase
Sister chromatids separate (at the centromere) Spindle fibers pull identical chromosomes to opposite sides of the cell. Chromosome Spindle Fiber Centromere

29 Events that occur during Telophase & Cytokinesis
The new nuclei form Chromosomes begin to uncoil Nuclear envelope reappears Cytokinesis: Cell splits into two Two identical daughter cells form Identical Chromosomes Nuclear Envelope Two Identical Daughter Cells Form (Cytokinesis)

30 Two Identical Daughter Cells form After Cytokinesis
In animal cells, the membrane pinches closed (cleavage furrow) In plant cells, a cell plate forms. nucleus with chromatin

31 Animal Cells = Cleavage Furrow (pinches the 2 daughter cells apart)
Plant Cells = cell plate forms (to divide the 2 daughter cells)

32 Crash Course – Mitosis 
Mitosis: Splitting Up is Complicated - Crash Course Biology #12 - YouTube

33 Mitosis wrap-up Mitosis Rap

34 cell cycle | Search | Discovery Education
Standard deviants videos cell cycle | Search | Discovery Education


36 Find a cell in the following stages: Interphase, Prophase, Metaphase, Anaphase, and Telophase of mitosis.

37 Cancer Do you know anyone (or of anyone) who has been diagnosed with cancer? If so, what cancer did they have? And what types of things did they go through? What type of cancers do you think are most prevalent?

38 Cancer … Mitosis Out of Control!!!!
Cancer results from out-of-control cell production. Abnormal masses of cells are called tumors.

39 Two Types of Tumors Tumors can either be:
Benign – abnormal mass of normal cells Malignant – mass of cells resulting from the reproduction of cancer cells. Brain Tumor (MRI)

40 Metastasis When cancer cells break off tumors and travel/spread to other places in the body, the cancer is said to have metastasized. Video: How cancer spreads -

41 Cancer Treatment Surgery Radiation Therapy Chemotherapy
Unwanted Side Effects – nausea, damage to organs, sterility, hair loss, etc.

42 Common Cancers Melanoma (type of skin cancer)
Leukemia (cancer of the circulatory system – blood) Lung Cancer Colon Cancer Breast Cancer Bladder Cancer


44 Warm - up Name the 3 reasons cell reproduction is necessary for organisms?

45 Meiosis Objectives Contrast haploid and diploid cells
Summarize the process of meiosis Compare mitosis & meiosis Explain how genetic variation occurs in offspring of populations

46 9 KEY CONCEPT Gametes (sex cells) have half the number of chromosomes that body cells have and they reproduce via meiosis (not mitosis)

47 4 haploid (n) gametes/sex cells
Mitosis vs. Meiosis Mitosis and meiosis are types of nuclear division that make different types of cells. Occurs in testes & ovaries Mitosis occurs in body cells Mitosis makes 2 diploid (2n) cells Meiosis makes 4 haploid (n) gametes/sex cells

48 Sexual Reproduction relies on Meiosis
Meiosis – a type of cell division that produces gametes/sex cells (egg & sperm) Meiosis occurs in sex organs (testes & ovaries) Still part of cell cycle (simply replace mitosis with meiosis)

49 You have somatic cells and germ cells.
(body cells) (sex cells) Germ cells develop into gametes (sperm & eggs) Germ cells are located in the reproductive organs. Gametes have DNA that can be passed to offspring. body cells (muscle cells) sex cells (sperm) sex cells (egg)

50 Each of your cells have:. 1. autosomes (regular ones). 2
Each of your cells have: 1. autosomes (regular ones) 2. sex chromosomes Your body cells have a total of 23 pairs of chromosomes. That is ___ total chromosomes. Chromosome pairs # 1-22 are autosomes. (=44 chromosomes) Pair # 23 are the Sex chromosomes, X and Y, (determine gender) Girl = X X Boy = X Y

51 Quick Check / Review Meiosis is a type of cell division that makes ______ cells in the ______ & _______ (organs) of our bodies. Somatic (body) Cells reproduce through ____________ (mitosis or meiosis). Sex Cells reproduce through __________ (mitosis or meiosis) How many total chromosomes are in your body cells???? _______ (hint: 23 pairs)


53 Body cells are diploid Gametes (sperm & eggs) are haploid
Fertilization joining of egg and sperm; occurs in sexual reproduction, results in a diploid zygote Diploid (2n) cells have two copies of every chromosome. = 46 chromosomes Body cells are diploid* Total = 46 Chromosomes (A set of chromosomes (23) come from each parent)

54 Haploid (n) cells have only one copy of every chromosome (or ½ the normal amount)
Gametes (sperm & eggs) are haploid. Total = 23 chromosomes (that’s ½ of 46!!)

55 Diploid (2n) vs. Haploid (n) Cells
Body Cells Contain 2 copies of each chromosome Total = 46 chromosomes (44 autosomes & 2 sex) Reproduce through mitosis Sex Cells Contain 1 copy of each chromosome Total = 23 chromosomes (22 autosomes & 1 sex) Reproduce through meiosis

56 Meiosis results in 4 haploid gamete cells
Meiosis occurs in reproductive organs (testes & ovaries) Involves 2 cell Divisions = (meiosis 1 & meiosis 2) Meiosis produces 4 haploid (n) gametes* Meiosis 1 Meiosis 2 4 haploid gametes Parent Germ Cell 2n During interphase 2n n n n n n n

57 Final product: 2 diploid Final product: 4 gametes
Mitosis vs. Meiosis Mitosis and meiosis are types of nuclear division that make different types of cells. Mitosis occurs in body cells Occurs in testes & ovaries Final product: 2 diploid (2n) cells Final product: 4 gametes (haploid (n) cells)


59 How do we get genetic variation?
During Prophase 1 (of Meiosis 1)… homologous chromosomes, while paired in “tetrads” undergo “Crossing Over” and swap genes for traits. This creates genetic variation in populations!!!

60 Crash Course - Meiosis Meiosis: Where the Sex Starts - Crash Course Biology #13 - YouTube

61 Meiosis video clip Meiosis review clip

62 Let’s play a review GAME!

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