Presentation on theme: "KEY CONCEPT Cells work together to carry out complex functions."— Presentation transcript:
1 KEY CONCEPT Cells work together to carry out complex functions.
2 I can describe the specialization in multicellular organisms. I can identify different types of stem cells.
3 Tissues are groups of cells that perform a similar function. Multicellular organisms depend on interactions among different cell types.vasculartissueleafstemlateralrootsprimaryrootSYSTEMSroot systemshoot systemTissues are groups of cells that perform a similar function.Organs are groups of tissues that perform a specific or related function.Organ systems are groups of organs that carry out similar functions.CELLTISSUEORGAN
4 Specialized cells perform specific functions. Cells develop into their mature forms through the process of cell differentiation.Cells differ because different combinations of genes are expressed.A cell’s location in an embryo helps determine how it will differentiate.Outer: skin cellsMiddle: bone cellsInner: intestines
5 Stem cells are unique body cells. Stem cells have the ability todivide and renew themselvesremain undifferentiated in formdevelop into a variety of specialized cell types
6 Stem cells are classified into three types. totipotent, or growing into any other cell typepluripotent, or growing into any cell type but a totipotent cellmultipotent, or growing into cells of a closely related cell family
7 Stem cells come from adults and embryos. Adult stem cells can be hard to isolate and grow.The use of adult stem cells may prevent transplant rejection.The use of embryonic stem cells raises ethical issuesEmbryonic stem cells are pluripotent and can be grown indefinitely in culture.First, an egg is fertilized by a sperm cell in a petri dish. The egg divides, forming an inner cell mass. These cells are then removed and grown with nutrients. Scientists try to control how the cells specialize by adding or removing certain molecules.
8 The use of stem cells offers many currently realized and potential benefits. Stem cells are used to treat leukemia and lymphoma.Stem cells may cure disease or replace damaged organs.Stem cells may revolutionize the drug development process.
9 Which sequence shows the progression from least complex structure to most complex structure? a. cell organ tissue organ systemb. cell tissue organ organ systemc. organ system tissue organ celld. organ system organ tissue cell
10 Which phrase best describes an organ system? a. group of specialized cells that forms organsb. group of cells that differentiates at the same ratec. group of tissues that performs a functiond. group of organs that work together
11 Which of the following is a direct result of a normal cell's ability to express only certain genes? a. Cells can become totipotent.b. Cells can grow and reproduce.c. Cells can mutate and adapt.d. Cells can differentiate and specialize.
12 Stem cells are important to multicellular organisms because of their a. capacity to differentiate.b. tendency to maintain homeostasis.c. potential to become totipotent.d. ability to relocate.
13 Which type of stem cell can grow into any other cell type? a. somaticb. multipotentc. totipotentd. pluripotent