Transcript Cell and animal reproduction

Cell & animal reproduction
Grade 6
Compiled by:
Alya Kays
Plants reproduction
Animal Cell
• The body is made up of millions of
tiny cells
• Most of the cell is made up of
protoplasm
• Cell parts:
 Nucleus
 Cytoplasm
 Cell membrane
Animal Cell
Nucleus
Cytoplasm
Cell
Membrane
SHAPE
• Plant cell is
rectangular in
shape.
• Animal cell is
spherical in
shape.
Plant cells
Animal cells
CELL WALL
• Plant cell is covered
by a thick cell wall.
• Cell wall is made up
of cellulose and
hemicellulose.
• Animal cell is
covered by a thin
cell membrane.
• It is made up of
Lipoprotein.
VACUOLE
• In plant cell, Vacuole is big, prominent
and permanent.
Vacuole
• In animal cell, Vacuole is small,
temporary and not so prominent.
PLASTIDS
• Plastids are present
only in plant cell.
• Plastids are of three
types.
• *Leucoplast
• *Chromoplast
• *Chloroplast
• PLASTID IS ABSENT
IN ANIMAL CELL.
Paramecium
Skeletal muscles attach
to bones. They help you do
things such as kick a ball,
chew food, or write. When
one of these muscles
contracts, or shortens, the
bone attached to the muscle
moves. Skeletal muscles are
voluntary—that is, you
control when they work.
Skeletal muscles consist of
cells containing light and
dark bands that make them
appear striped.
Nerve cell:
This photomicrograph shows a
number of multipolar nerve cells.
The central cell body is clearly
visible in each of the cells, as are
the dendrites. The dendrites are
short extensions of the nerve cell
body that
function in
the
reception of
stimuli.
• The epithelium is a protective layer
of cells that covers an organ surface
or lines a body cavity. Shown here is
a layer of simple squamous (scaly)
epithelium. Skin is composed of
several layers of epithelial cells.
Bone cell
Osteocytes
Cell Division
• Mitosis
– Increases total number of cells
– Results in animal growth
– Chromosomes pairs are duplicated
Cell Division
• Meiosis
– Produces gametes
– Only have one-half the
chromosomes of normal cells
Gametes
Reproductive Terminology
Species
Cows
Ewes
Sows
Hens
Mares
Goats
Frog
Act
calving
lambing
farrowing
hatching
foaling
kidding
hatching
Offspring
calf
lamb
pig
chick
foal
kid
tadpole
Mammals
Reproduction
Objective: Specify how the
reproductive system for
mammals functions
Terminology
• Estrus
– When a female is receptive
to be bred
• Lactation
– Period of time that milk is
secreted by the mammary
glands
• Parturition
– Than act of giving birth
Reproductive Functions of the
Female
Estrous cycle - time from one heat period (or
menstrual cycle) to the next.
Length of estrous cycle by species:
Cow
19 - 21 days
Ewe
16 - 17 days
Sow
19 - 21 days
Mare
21 - 24 days
Woman
28 days
Hen
none
Female Tract
Female Reproductive System
• Ovary - the ovary is comparable to the
male testicle and is the site of gamete
production.
– A bovine animal has 20,000 potential eggs per
ovary, while a human female has 400,000
potential eggs per ovary.
– Ova are fully developed at puberty and are not
continuously produced as in the male.
– All species contain two functional ovaries except
for the hen which has only a left functioning
ovary.
Female Reproductive System
• Uterine Horn - The anterior, divided end of
the uterus in the cow, ewe, and mare. Sow
has only 2 horns, no body, woman has no
horns, only body.
• Uterus - Muscular sac connecting fallopian
tubes and cervix
1. Sustains the sperm and aids in its transport
2. Supports embryo and fetus during gestation
3. Expels fetus at parturition
Female Reproductive System
Reproductive Functions (Female)
Steps in the female reproductive
process:
1. Ovulation
— Produce gamete (ova or ovum)
— Release of egg(s)
— Infundibulum pushes the
ovum into the fallopian tube
Ovulation Rates
Ovulation Rates by Species
Cow1 egg per estrus
Ewe1 to 3 eggs per estrus
Sow10 to 20 eggs per estrus
Mare1 egg per estrus
HenApprox. 28 eggs per month
Fertilization
• When the sperm from a male
reaches the egg from a female
• Two cells join to form a
complete cell
• Pairs of chromosomes are
formed again
• Many different combinations of
traits are formed
Fertilization
Figure 16.13 Fertilization
Reproductive Functions (Female)
Gestation and Lactation Periods:
Species
Cow
Gestation Period
275 - 285 days
Ewe
Sow
Mare
Woman
115
112
330
270
- 142 days
- 115 days
- 345 days
days
Lactation(Milking)
beef 180 - 270 days
dairy 305 - 365 days
60 - 90 - 120 days
21 - 42 days
90 - 150 days
? years
Baby development
Human baby
Birds
Reproduction in
Poultry
Objective: Specify how the
reproductive system for
poultry functions
Reproduction in Poultry
The poultry oviduct has five parts:
1) Vagina
– Holds the egg until laid
2) Uterus
– Secretes the shell
3) Isthmus
– Adds the two shell membranes
4) Magnum
– Secretes the albumen
5) Infundibulum
– Where fertilization takes place
Reproduction in Poultry
• Major difference:
– Embryo of livestock develop inside the
female’s body while the embryo of poultry
develops inside the egg.
• Poultry only have the left ovary and
oviduct when mature
• The yoke is the ovum
• Chicken Incubation
– 21 days
1- A butterfly starts its life as an
egg, laid by a female adult
butterfly after mating.
Butterfly eggs vary in size and
shape, but most are
surrounded by a protective
hard shell.
2- A caterpillar develops
within the egg and
then eats its way out
of the shell.
• 3- When the caterpillar
reaches its final size it
stops feeding. The
caterpillar wriggles and
twists to gradually remove
its old skin, revealing a new
protective skin called the
chrysalis.
4- A caterpillar spends all its time
eating. As it grows, the caterpillar
becomes too large for its skin and
molts (sheds its skin) to reveal
new skin. Depending upon the
type of butterfly, caterpillars molt
four or five times.
5- Inside the chrysalis, the
caterpillar changes from a
wormlike creature into an
adult butterfly.
6- When the butterfly
reaches adulthood, it
leaves the chrysalis. It
pumps blood into its
crumpled wings and
expands them to their
full size before flying
away.
Amphibians
Life Cycle of a Frog
Metamorphosis
• Metamorphosis is the changes
that a frog goes through
during its life cycle.
• There are four main stages in
the life cycle of the frog.
Egg
• The first stage in the life cycle
of the frog is the egg.
• A frog lays many eggs at one
time.
• The eggs are covered with a
jellylike coating.
Tadpole
• The second stage of the frog
life cycle is the tadpole.
• Hatched tadpoles have gills
for breathing in the water.
• They have a tail, but no legs.
• As a tadpole grows,
lungs begin to form.
• Back and front legs
begin to grow. These
parts allow the adult
frog to live on land.
Adult Frog
• Once the lungs form and
begin to work, the gills
and tail disappear.
• The adult frog is now
ready to live on land.
Frog life cycle
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