Download Diapositiva 1

Supervised by Teacher Carlotta
Asexual reproduction involves only one organism. Descendents develop directly from
the
Body of the progenitor. They are identical to the progenitor.
For example:
•In unicellular organism, the only cell divides into two new cells.
•In some simple invertebrates, the descendents forms slowly
from the progenitor’s body, like in the Polyp.
A new plant can grow from a root or part of the stem of another plant.
Other plants, like moss or ferns, produce cells called spores.
PHASES OF REPRODUCTION
1. CREATION OF THE GAMETES
Animals have reproductive organs to perform sexual reproduction.These organs
can be male or female.
- Female Organs (Ovaries) produce Female Gametes (Ovules)
- Male Organs (Testicles) produce Male games (Sperm)
2. FERTILIZATION:
External: the union of the ovule and sperm occurs outside the female
reproductive organs.
Internal: the union of the ovule and sperm occurs inside the female
reproductive organs.
3. DEVELOPMENT OF THE ZYGOTE AND EMBR
The zygote formed by fertilization forms an embryo.
-Inside an egg (oviparous):
The embryo feed on nutritious subtances contained in the egg. It breath througth
the shell. When is development is complete, it leaves the egg (hatching).
-Inside the female reproductive system (viviparous):
The embryo takes food and oxygen from the body of the mother. When its
complete it leaves the inside of the mother. This is called birth.
THE FLOWER:
*Pistil: is the female part of the flower. Inside (In the ovary) there are the ovules
(the female gametes)
*Stamens: are the male part of the flower. Pollen grains which contain the male
gametes, form part of the stamens.
*Calyx: is the lower part of the flower. It is formed by small leaves called sepals.
*Corolla: are leaves around the stamens and the pistil. These leaves are called
petals. They are colorful to attract the insects.
PHASES OF
REPRODUCTION
-Pollination
and fertilization:
•POLLITATION is the journey of the grains of pollen from the
staments of one plant’s flower to the pistil to another one.
•FERTILIZATION when a grain of pollen reaches the pistil it gets through
a fine tube to reach the ovules. The union of the gametes,
or fertilization, produces a zygote, which forms de embryo.
-Formation of the fruit and the seed:
After fertilization, the flower loses its stamens and corolla and its pistil
develops to form a fruit. Inside the fruit, the embryo is surrounded
By a capsule, full of nutritious substances, called the seed.
-The germination of the seeds:
When a seed is buried underground and finds the correct humidity and
Temperature, it germinates. This means it breaks through its surrounDing capsule and grows roots and little leaves. This is the new plant.
What’s hermaphrodites?
There are animals that have the two reproductives organs
male and female.
For example:
The Snail, the earthworm and the clown fish.
LOOK THIS PHOTOS THEY ARE AMAZING!: