7 Science: Chapter 3 Review

mitosis

division of the nucleus; results in two genetically identical nuclei; consists of four steps

mitotic phase

the part of the cell cycle where the cell divides; consists of mitosis and cytokinesis

cytokinesis

division of the cytoplasm; the last step of the mitotic phase

furrow

created by animal cells during cytokinesis; the furrow or indent, deepens until the two identical daughter cells fully split apart.

cell plate

new cell wall forming between new cells during cytokinesis in plant cells

prophase

chromosomes condense, nuclear envelope and nucleolus dissolves, spindle apparatus forms

metaphase

sister chromatids line up in the middle of the cell

anaphase

the sister chromatids are pulled apart and begin moving to opposite sides fo the cell by shortening spindle fibers

telophase

nucleus re-forms, chromosomes relax; spindle apparatus disappears

kinetochore

physical spot on a chromosome that spindle fibers attach to

centromere

central region where two chromtids are held together

stem cell

unspecialized cell that can give rise to one or more types of specialized cells

organ

A collection of tissues that carry out a specialized function of the body

tissue

A group of similar cells that perform the same function.

organ system

group of organs that work together to perform a complex function

spindle apparatus

consists of centrioles and spindle fibers/microtubules; aids in mitosis and cytokinesis

interphase

consists of G1, S, and G2; longest part of the cell cycle

S phase

the second step of interphase; replication of DNA (the S stands for synthesis because new DNA is being made)

prokaryote

a unicellular organisms that does not have organelles; bacteria and archaea

eukaryote

a multicellular or unicellular organism with membrane-bound organelles, including a nucleus; examples include plants, animals, and fungi.

purpose of cell division

multicellular organisms use mitosis to repair damage, replace worn out cells, and grow.

unicellular eukaryotes use mitosis to reproduce

Remember, prokaryotes do not undergo mitosis because they don’t have a nucleus!

meristem

a region in plants where undifferentiated cells are actively dividing, allowing for growth and the formation of new tissues; plants have a root meristem and a stem meristem.

chormatin

the relaxed form of DNA

sister chromatids

the identical copies of a chromosome that are joined together by a common centromere, created during DNA replication during S phase.

chromosome

a structure within cells that contains genetic material, consisting of DNA and proteins, and is visible during cell division.

connective tissue

a type of animal tissue that supports and protects: examples include bones, cartilage, and blood

nervous tissue

a type of animal tissue that brings information to and from the central nervous system; helps an organism to sense external information and respond to it.

muscle tissue

a type of animal tissue responsible for movement, consisting of cells that can contract and relax.

epithelial tissue

a type of animal tissue that forms protective layers on body surfaces and lines cavities and organs

dermal tissue

a type of plant tissue that supports, protects, and prevents water loss.

vascular tissue

a type of plant tissue that transports nutrients around the plant

ground tissue

a type of plant tissue that is the site of photosynthesis

What phase of mitosis is shown in the picture?

anaphase

What phase of mitosis is shown in the picture?

metaphase

What phase of mitosis is shown in the picture?

telophase (cyotkinesis is also occuring)