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I. Cell Composition
A. Cell or Plasma Membrane
1. surrounds the cell
2. controls passage of materials
in and out of cell
3. selectively or semipermeable
4. composed of protein, lipids,
and carbohydrates
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- Name several functions of the cell membrane
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B. Cytoplasm
1. endoplasmic reticulum
a. functions
(1). tubular communication system
(2). transports materials through the cell
(3). provides attachments for ribosomes
(4). synthesizes lipids
b. types
(1). smooth-without ribosomes
(2). rough--with ribosomes
2. ribosomes--protein synthesis; found in the cytoplasm and ER
3. Golgi apparatus (body or complex)--manufactures carbohydrates
and packages it with proteins for secretion
4. mitochondria--release energy from food; produces the energy necessary
for the cell to function
5. lysosomes (suicide sacs)--contain digestive enzymes
6. vacuoles--store food or water
7. centrosome--consist of two centrioles; aid in reproduction
8. fibrils and microtubules--first word are shaped like rods and
the second like tubes; function in providing support to cytoplasm
and help move objects within the cytoplasm
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- Name several organelles found
in the cytoplasm.
- Give at least one major function
of each organelle.
- What is the difference between
smooth and rough ER?
- Name two places that you would
find ribosomes.
- Why are mitochondria important
to the function of the cell?
- Why are lysosome called suicide
sacs?
- How can you tell the difference
between fibrils and microtubules?
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C. Nucleus
1. nuclear membrane--gives shape and support to the nucleus; controls
material in and out of the nucleus
2. nucleolus--produces ribosomes and RNA
3. chromatin--coiled fibers that are transformed into chromosomes
during reproduction; contain the hereditary information
4. nucleoplasm--material found in the nucleus
D. Additional terms
1. microvilli--tiny projections from the cell membrane that helps
increase the surface area of the cell
2. pinocytic vesicles--indentation in the cell membrane that allow
for entrance of exit of large substances through the cell membrane;
produces vacuoles
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- What is the function of the nucleus?
- Give more than one function of
the nuclear membrane.
- Why is the nucleolus important
to the cell?
- What two substances give the nucleus
its shape?
- What are microvilli important,
especially to something like the lining of the intestine?
- How will you tell microvilli from
pinocytic vesicles
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II. Life Cycle of the Cell
A. Mitosis--cell division
1. function-reproduction and
replacement of cells
2. somatic cells--body cells
3. chromosomes
a. numbers--46
b. DNA
(1). composition--a sugar,
4 bases and as phosphate unit
(2). base pairs--adenine
with thymine and cytosine with guanine
c. gene--a specific sequence
of base pairs in a chromosome
d. genome--entire set of chromosomes
in a cell
e. RNA
(1). function--transfer the
genetic information from the nucleus to the cytoplasm
(2). differences--single
strand instead of a double strand; contains a different sugar;
the base uracil replaces thymine
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- What cells are involved in mitosis?
- Which cells are involved in meiosis?
- How many chromosomes are found
in our cells?
- Which are always matched with
which?
- What is the difference between
a gene and a chromosome?
- So what do you think is the Human
Genome Project?
- How is RNA different from DNA?
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4. Interphase--stage in life cycle when cell grows and forms new
organelles: DNA replicates; ends when cell begins to undergo mitosis
5. Stages
a. prophase--chromsomes appear; centrioles separate and travel
to opposite sides of the cytoplasm; nuclear membrane and nucleolus
disappear; spindle fibers form
b. metaphase--chromosomes line up along the middle; spindle fibers
begin pulling the chromosomes apart (separating the individual chromosomes)
c. anaphase--separated chromosome move in opposite directions
d. telophase--chromosomes reach the centrioles; chromosomes elongate
and chromatin; nuclear membrane forms; nucleoli appear; centrioles
duplicate and the animal cell pinches in two
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Name the stage in which the following
occur:
- chromosomes appear
- cell pinches in two
- chromosome line up across the
middle
- centrioles move to opposite sides
- nucleolus and nuclear membrane
reappear
- DNA duplicates
- nucleolus and nuclear membrane
disappears
- separated chromosomes move to
opposite sides
- chromosomes become chromatin
Check your ANSWERS!!
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B. Meiosis
1. definition--division of the sex cells
2. human numbers--23 in each egg and each sperm
3. gametes (germ cells)--sex cells
4. zygote--fertilized cell
5. blastocyst--a hollow ball of cells
6. embryo--from fertilization until the end of 8 weeks
7. fetus--from 9 to 39 weeks
8. primary germ layers--each layer gives rise to different structures
a. histogenesis--process of cells developing into different kinds
of tissues
b. organogenesis--process of tissues developing into various organs
c. stem cells--cells that have the ability to divide and to give
rise to specialized cells
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- What are the differences between
mitosis and meiosis?
- Name the steps in the development
of a fertilized egg.
- What is the importance of a germ
layer?
- Define:
- histo
- organo
- genesis
- cyst
- germ
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