Transcript 11 - Tissues (Animal & Plant)

Draw a cell
1. fold a page in half
2. on the top half draw a circle
3. on the bottom half draw a rectangle
4. each represents a cell type
label one ‘animal and one ‘plant’
now add the following (without looking at your notes)
read the list and plan ahead before starting
nucleus
endoplasmic reticulum
chloroplast
centriole
golgi apparatus
cell wall
vacuole
mitochondria
not all parts will be in both cells
Animal cell
endoplasmic
reticulum
membrane touching
nucleus
nucleus
round
golgi complex
floating membrane
mitochondria
sausage shaped –
interior structure
endoplasmic
reticulum
nucleus
chloroplast
oval with green
insides
golgi complex
vacuole
large, empty
mitochondria
cell wall
thick, outside membrane
Cell Specialization and Tissues
sexually reproducing organisms start out life as
a fertilized egg cell  a zygote
mitosis allows this one cell to divide into
many billions of cells
without cell specialization you would just be a big ball
of identical cells all doing identical things
cell specialization occurs when any one cell differs from
those around it in appearance or function
Factors That Influence Cell Specialization
1. the cell’s cytoplasm
the cell organelles may NOT be equally
distributed after mitosis
a cell may get more: vacuoles  storage
golgi  packaging
mitochondria  energy
ribosomes  proteins
2. environmental conditions
temperature cells are exposed to may
influence expression of genes
all cells in the Siamese cat have
the potential to make the black
pigment, but only the cells below
36oC do so
nutrients available to the cell
how much and what a stem cell is
‘fed’ affects its development
3. the effect of neighbouring cells
where a cell is in a multicellular organism influences
how it behaves
each cell receives chemical signals from the cells
around it
a cell receives different signals based on where it
is in the organism
these signals then cause the cell to
differentiate appropriately
it is why we have a thumb and four fingers, rather than just all
fingers and no thumb
Types of Animal Tissues
1. Epithelial
these tissue form a layer around other tissues
a. skin epithelia
flat cells that form a semi-permeable barrier
between the body and the outside world
b. columnar epithelial
cells lining the intestine, stomach, glands
secrete mucous, absorb materials
2. muscle
a. skeletal muscle
made up of long cells that align to look striped
attach to bones
to allow movement
can contract quickly and with force
b. smooth muscle
made up of cells that do not look striated (striped)
found in blood vessels, digestive organs
contract slowly
but can sustain contractions
c. cardiac muscle
found only in the heart
appear to be striated unevenly
work together, all contract at once
do NOT get tired
3. nervous
consist of neuron cells
which have long projections
to receive & transfer signals
function to coordinate body actions
4. connective
a. bone
consists of protein hardened by calcium
needed for protection support & movement
b. fat or adipose tissue
large cells
around organs and under skin
provide energy storage
and insulation
whale blubber
c. blood
red blood cells
carry oxygen to cells
white blood cells
attack invaders to protect the body
platelets
release fibrin to clot the blood
Types of Plant Tissues
1. Meristematic Tissue
not dividing
unspecialized tissue capable
of dividing by mitosis
dividing
only found in root tips, buds
and cambium
not dividing
2. Epidermal Tissue
protective outer coating
involved in water entering roots
and gases entering or leaving leaf
3. Ground Tissue
provides support for stem
all 3 are ground
tissue
storage of food and water in roots
site of photosynthesis in leaves
all the cells with
chloroplasts
4. Vascular tissue
xylem moves water & dissolved minerals
up from the roots
series of tubes moving
water & minerals up
phloem moves dissolved sugars (food)
down from the leaves
series of tubes moving
water & sugars down
xylem & phloem are found together in a
vascular bundle
cambium is meristematic tissue that makes xylem
& phloem
Comparing animal and plant tissues:
Explain why each animal tissue corresponds to the
given plant tissue
plant
epidermal
animal
epithelial
what they have in common
both protect
both allow entry animals absorb,
plants allow entry
ground tissue
connective
both support
both store
vascular tissue
muscle
both transport
(remember arteries & veins are
muscles tissue)
meristematic tissue
none
all animal tissue can divide &
grow
Challenges with cell specialization
a. regeneration
if a salamander
loses a limb it
can regenerate
but humans can not why
before birth all stem cells are set in humans
b. manipulating stem cells
unspecialized stem cells can be taken from
an unwanted embryo
problems of moral issues
more recently differentiated adult cells have been turned
into unspecialized stem cells
value of stem cells
1. replace cells damaged by drugs / radiation
eg. bone marrow in cancer treatments
2. replace nerve cells as these do not grow in adults
eg. spinal injuries
3. replace diseased cells
eg. leukemia
4. replace worn out organs
eg. grow a bladder in the lab from own cells