Small But Mighty: Cellular Biology and Animal Taxonomy

1. Cellular Biology and Animal Taxonomy Cells – Small But Mighty

2. Objectives • Draw and label the cellular structures • Describe the functions of cellular structures • Differentiate between Mitosis and Meiosis • Discuss the relationship of tissues, organs, and systems • Explain how taxonomy is used to classify living organisms • Use binomial nomenclature to write scientific names of common livestock • Trace the domestication of farm animals

3. What is the smallest biological unit?

4. Small, but Mighty • Take in nutrients • Excrete waste products • Secrete proteins • Perform cellular work • Respond to their environment • Reproduce themselves

5. Organisms vary….. • Single-celled bacteria • Multicellular whole animals • Swine • Sheep • Cattle • Horses

6. Cell theory • Basic unit of life = Cell • A cell only originates from other cells. • All organisms are made up of one or more cells.

7. Functions of all cells are similar in the following ways • They must take up nutrients from their external environment. • They must excrete waste products into their external environment. • They must do some kind of work (See next slide for complete list) • They must reproduce themselves

8. What kind of work???? • Synthesize proteins. Example… liver cells • Store energy. Example… fat cells • Carry oxygen. Example… red blood cells • Transport electrical impulses. Example… nerve cells • Store minerals. Example… bone cells • Move. Example… muscle cells

9. Cells • Little factories with different departments responsible for varying duties

10. Outside wall of the factory • The cell membrane is made of a thin layer of lipid (fat-like film). Separates cell contents from the external environment.

11. Cell Membrane • Imbedded in this lipid layer are specialized protein “doors” allowing large molecules which are raw materials such as proteins and carbohydrates to pass into the cell. • Newly made proteins (finished products) and cellular waste products pass out of the cell through the same protein “doors”.

12. Cell Layout • Individual organelles, or compartments, within the cell are also separated by lipid layers. • Similar to walls separating rooms in a manufactoring plant.

13. Other factory analogies • Inside the cell factory is the “office” • Known as the nucleus • The nucleus controls all cell activity.

14. Other factory analogies • Chromosomes are small strands of genetic material residing in the nucleus. • Chromosomes are made up of DNA (Deoxyribonucleic Acid).

15. Other factory analogies • DNA is a genetic compound that controls inheritance/heredity. • Chromosomes contain many small, coded pieces of DNA called genes

16. “The apple doesn’t fall far from the tree!!!!” • Chromosomal genes contain the blueprint for the work the cell has to do. • It also has the instructions for the cell to replicate itself. • Genes control specific economically important traits as well as physical characteristics.

17. Explain how only a few cells can be cloned to create a whole new organism. • Bring your findings to class tomorrow written out • legible handwriting or typed • ½ to full page

19. Explain how only a few cells can be cloned to create a whole new organism. • Every cell contains all the genes necessary for the entire organism. • Only those needed to do a certain type of work are active. • Example: a liver cell has the genes to become a heart, but only the genes needed to perform liver functions are active in a liver cell.

20. Gels, Jellies, and Goops • The jellylike substance between the cell membrane and the nucleus is called the cytoplasm.

21. More factory analogies • Endoplasmic reticulum • Ribosomes • Mitochondria • Lysosomes • Golgi bodies

22. Endoplasmic Reticulum • Network of membranes from the cell membrane to the nucleus. • The “corridors” within the factory • Transports all incoming raw materials and outgoing cellular products

23. Ribosomes • Where new proteins are manufactured • Most are attached to the endoplasmic reticulum • The actual “workers” of the factory

24. Mitochondria • Small egg-shaped organelles • Manufacture adenosine triphosphate • ATP used as an energy source for the cell • The “cooks” of the factory

25. Lysosomes • Round organelles • Function to digest and recycle molecules which are no longer useful. • The “green team” of composters for the fatory.

26. Golgi Bodies • Flat, membrane encased • Final assembly and packaging process of cellular products • The shipping and handling department of the factory.

27. Cellular Reproduction • Cells go through a life cycle of growth and reproduction called the Cell Cycle • The entire Cell Cycle has to phases • Interphase • Period between cell divisions • Cell Division • Most of a cells life is spent in interphase

28. Interphase • Divided into three periods • G1, S, and G2

29. G1 = First Period • G1 – first period • Cell grows in size by increasing the number of organelles

30. S = Second Period • S – second period • Genetic material replicates or copies itself so there are two identical sets of chromosomes. • Identical sets of chromosomes are called sister chromatids. • Chromatids are still attached to each other at a central point called the centromere

31. G2 = Third Period • G2 – Third Period • Cell manufactures organelles and prepares for cell division a.k.a. mitosis

32. Cell “Self-management” • At several points during the cell cycle the cell inspects the cell replication process • Determines if genetic material has been properly copied • If an error occurred in the copying process it destroys itself • Process known as apoptosis (programmed cell death)

33. Apoptosis • Failure of a cell to identify improperly copied genetic material is the first step in the development and growth of cancerous tumors.

34. Mitosis • Actual division of non-sex cells • Divided into four periods • Prophase • Metaphase • Anaphase • Telophase

35. Prophase • Chromosomes thicken and become visible (like mitosis) • Chromosomes are present in homologous pairs • Total of four sister chromatids

36. Metaphase • Homologous pairs line up on the axis of of the dividing cell opposite from each other

37. Anaphase • The homologous pairs of chromosomes leave each other and are pulled toward the opposite poles • Pulled by spindle fibers

38. Telophase • The cells physically divide • Each daughter cell now contains one chromosome from each pair

39. Meiosis I • Known as reduction division • Chromosome reduced from diploid to haploid • During Mitosis daughter cells are still diploid

40. Meiosis II • Each daughter cell divides again • At the end of Meiosis two haploid cells from each of the daughter cells exiting from Meiosis I • Four final haploid cells • Each of the four final haploid cells (gametes) contains one strand from the original homologous pairs of chromosomes

42. Cells, Tissues, Organs, and Systems • In multi-cellular animals, individual cells are specialized to perform a specific task. • Muscle cells = support & locomotion • Bone cells = structural support • Red blood cells = carry oxygen • Fat cells = store energy

43. Cells to Tissues • Specialized cells combine to make up tissues. • Example: Cartilage

44. Tissues to Organs • Cells and tissues work together to form organs • Example: Liver

45. Organs to Systems • Tissues and organs combine to form systems. • Example: Skeletal, Muscular, Respiratory, Circulatory, Digestive, Nervous, Endocrine, and Reproductive Systems

46. Skeletal System • Bone and cartilage • Support structure for the body

47. Muscular System • Muscle tissue • Attached to skeletal system by tendons • Allows for movement

48. Respiratory & Circulatory • Combine to ensure the internal organs receive oxygen • Lungs, heart, and miles of blood vessels

49. Digestive system • Stomach, intestines, liver • Combine to break food into particles small enough to be carried by the bloodstream and utilized

50. Nervous System • Brain, Spinal Cord, and Specialized Nerve cells. • Carry electrical impulses to the brain for processing