The Basis of Cellular Inheritance

Chapter 9

Vocabulary Clarification

Human Karyotype

HOMOLOGOUS CHROMOSOMES: carry the same genetic info, one copy is from Mom and one copy is from Dad

XX = Female

XY = Male

Diploid vs. Haploid

Diploid cells (2n) have 2 sets of chromosomes (somatic cells- almost all cells in the body)

Haploid cells (n) have one set of chromosomes (gametes or sex cells)

The Cell Cycle

INTERPHASE

Plant Cell

Phases of Mitosis: PROPHASE

Plant Cell

Phases of Mitosis: METAPHASE

Plant Cell

Phases of Mitosis: ANAPHASE

Plant Cell

Phases of Mitosis: TELOPHASE

Plant Cell

Cell Plate

Regulating The Cell Cycle

• Cells complete the cell cycle at different paces; some cells don’t divide

(ex: neurons, cardiac muscle)

• Special proteins direct the sequence of events and serve as “checkpoints”

• When this “control system” malfunctions, cells reproduce at the wrong time and place leading to tumors

Tumors and Cancer

Benign Tumors (not cancer)

A mass of normal cells

Malignant Tumors

Masses of cancer cells

Cancer cells displace normal tissue, enter blood vessels, and can metastasize, or spread from their site of origin

Combating cancer requires a deep understanding of the cell cycle

Cancer Treatment

SURGERYRemove tumor from tissue

RADIATIONExpose dividing tumor cells

to high-energy radiation to disrupt division

CHEMOTHERAPYUse antimitotic drugs to

prevent spindle formation or function

SIDE EFFECTS• Damage reproductive

cell development (sterility)

• Damage intestinal cells (nausea)

• Damage hair follicle cells (hair loss)

Asexual vs. Sexual Reproduction

ASEXUAL

• Offspring inherit all their genetic information from ONE parent (genetic clones)

• Mitosis

SEXUAL

• Genetic information from two parents combines to make offspring (genetically unique offspring)

• Meiosis

Mitosis vs. Meiosis

MITOSIS MEIOSIS

MITOSIS MEIOSIS

Growth, repair, asexual reproduction

MITOSIS MEIOSIS

Growth, repair, asexual reproduction

Formation of gametes, sexual reproduction

MITOSIS MEIOSIS

Growth, repair, asexual reproduction

Formation of gametes, sexual reproduction

2 daughter cells genetically identical to

parent

MITOSIS MEIOSIS

Growth, repair, asexual reproduction

Formation of gametes, sexual reproduction

2 daughter cells genetically identical to

parent

4 daughter cells genetically unique from each other and parent

MITOSIS MEIOSIS

Growth, repair, asexual reproduction

Formation of gametes, sexual reproduction

2 daughter cells genetically identical to

parent

4 daughter cells genetically unique from each other and parent

Diploid Daughter Cells

MITOSIS MEIOSIS

Growth, repair, asexual reproduction

Formation of gametes, sexual reproduction

2 daughter cells genetically identical to

parent

4 daughter cells genetically unique from each other and parent

Diploid Daughter Cells Haploid Daughter Cells

MITOSIS MEIOSIS

Growth, repair, asexual reproduction

Formation of gametes, sexual reproduction

2 daughter cells genetically identical to

parent

4 daughter cells genetically unique from each other and parent

Diploid Daughter Cells Haploid Daughter Cells

One Division

MITOSIS MEIOSIS

Growth, repair, asexual reproduction

Formation of gametes, sexual reproduction

2 daughter cells genetically identical to

parent

4 daughter cells genetically unique from each other and parent

Diploid Daughter Cells Haploid Daughter Cells

One Division Two Divisions