3. Reproduction Comparisons
Sexual Reproduction Asexual
Reproduction
Fertilization occurs No fertilization occurs
(combining a male and
female sex cell)
Needs two parents Only needs one parent
Occurs in almost all Occurs in simple animals
animals and in many and many plants
plants
Offspring are genetically Offspring are identical
5. Advantages
-Produces genetic diversity (more variety in a
species)
-One disease may not kill all individuals
-Species can change to survive in different
environments
Parents
Children
x
6. How is the beginning cell different
from the cells that are formed?
Meiosis: Preparing Sex Cells
Meiosis prepares sex
cells
•Sex cells must have half
the number of
chromosomes
•When sex cells combine,
the new individual has
the correct number of
7. MEIOSIS VS. MITOSIS
Mitosis Meiosis
Occurs in eukaryotic Occurs only in sex cells
cells (Asexual (for Sexual
reproduction) Reproduction)
Produces 2 cells Produces 4 cells
Cells have normal Cells have half the
number of number of
chromosomes chromosomes
8. Types of Sexual Reproduction:
Pollination & Fertilization (in
plants)
9. Pollination (in Plants)
Sexual
Reproduction
Only occurs inside
the flowers of
plants (male cells) are transferred to
Pollen
pistil (female parts) of a different flower
Plants don’t move: pollen is transferred
by wind, insects and animals
10. Types of Sexual Reproduction:
External Fertilization (in many
aquatic animals)
11. External Fertilization (in many
aquatic animals)
Sexual Reproduction
Occurs inside the water
Eggs (female cells) are
released into the water and
sperm (male cells) are
released near the eggs
Males and females don´t
need to touch each other
12. Types of Sexual Reproduction:
Internal Fertilization (in most
animals)
13. Internal Fertilization
Sexual Reproduction
Occurs in most animals
Male animals have a special
structure to insert their
sperm into the female
An egg (female cell)
combines with sperm (male
cell)
14. SEXUAL REPRODUCTION
TYPES
Pollination & External Internal
Fertilization Fertilization Fertilization
Occurs in which Plants Aquatic animals Most animals and
organisms? aquatic mammals
Occurs in which Land Water Mostly land and
environments? some water
Males and No No Yes
females
touch/join?
Key Vocabulary Pollen = male sex Sperm = male sex Sperm = male sex
cell cell cell
Stamen = male Egg/ova = female Egg/ova = female
flower structure sex cell sex cell
Pistil = female flower
structure
17. Advantages
-Simple process that can be very quick
-Produces many organisms with very little
effort
-Produces exact copies of organisms which
may be perfect for the needed environment
(like replacing lost skin cells)
19. Binary Fission (in prokaryotes)
Asexual Reproduction
Occurs in prokaryotes
(simple cells) like bacteria
A cell copies its contents
then divides in half
Fast and easy
All cells are identical copies
21. Mitosis(in eukaryotes)
Asexual Reproduction
Occurs in eukaryotes (cells
inside plants and animals)
A cell copies its contents
(including the nucleus) then
divides in half
Fast and easy
All cells are identical copies
Helps replace dying and old
cells inside organisms
23. Roots or Stems (in plants)
Asexual Reproduction
Plants send out roots or
stems to grow up into new
individuals
All new individuals are
identical copies
25. Budding (in simple animals)
Asexual Reproduction
New organism (with
identical DNA) grows on top
of parent
New organism may separate
from parent (like yeast) or
may stay attached forever
(like coral)
26. Types of Asexual Reproduction:
Fragmentation (in simple
animals)
27. Fragmentation (in simple
animals)
Asexual Reproduction
Parent organism broken
into pieces (fragments).
Each fragment becomes a
new, genetically identical
individual
28. TYPES
Binary Mitosis Roots or Budding Fragmentatio
Fission Stems n
Occurs in which Prokaryoti Eukaryot plants Simple Simple
organisms? c cells ic cells animals animals
Occurs in which Inside inside Land Water Water and
environments? prokaryote animals and land land
s (land and
and water) plants
General process A cell A cell Plants New Parent breaks
copies its copies send out organism into pieces
contents its roots or grows on and each
and contents stems to top of the fragment
divides in (includin grow into parent becomes a
half g new then new individual
nucleus) individuals stays
and attached
divides or
in half separates