Grade 10 Biology- 2.6 Specialized and Stem Cells

Single-celled organism

Rely on organelles in just one cell to perform all life functions

5 types of single-celled organism:

Bacteria, amoeba, yeast, euglena, paramecium

Multicellular organism

Larger organisms with many cells need specialized cells to perform specific functions.

Cell specialization

Cells have different structure and functions. There’s 200+ cell types

Muscle cells structure

Long and thin

Muscle cell function

• Change shape and contract

• Lots of mitochondria for energy

Muscle cell picture

Nerve cells structure

Long, threadlike branches

Nerve cell function

• send and receive signals

• Called neurons

Nerve cell image

Red blood cells structure

Doughnut shaped middle without a hole

Red blood cells function

• provides large surface area to carry oxygen

Red blood cell picture

Bone cells structure

Hard material containing minerals

Bone cell function

• strength and support

Bone cell picture

Skin cells structure

Thin, flat, layered

Skin cells function

• Barrier (wall) to keep out viruses and bacteria and to keep in moisture

Skin cells picture

All cells start as identical cells called____

Stem cells

Cell differentiation

The series of events through which stem cells develop into specialized cells

Cell regeneration

Replacing dead cells with new ones, all multicellular organisms have this ability

What can humans NOT regenerate?

Spinal cords, brain cells, etc

What can become any kind of cell?

Stem cells

What happens in leukemia?

Bone marrow cells grow uncontrollably, crowding out healthy stem cells

Totipotent stem cell

The early embryo- first four days. Can make all cell types

Pluripotent stem cell

Embryonic after 5 days, also (found in) umbilical and placenta. Can make most cell types

Multipotent stem cell

Adult tissue specific, after birth. Can only make a few cell types

Induced pluripotent (iPS) stem cell

Genetically reprogrammed from adult cells- makes regular cells into stem cells

Meristematic stem cell

Stem cell found in plants- tips of stems, leaves, roots