Download Asexual and Sexual Reproduction

Asexual and Sexual
Reproduction
Subtitle: how new generations
form
Asexual Reproduction
Formation of new individuals from a single
individual – one parent
Asexual Reproduction
There are several ways
asexual reproduction can
occur including:
– Binary fission
– Budding
– Mitosis
• Primary form of
reproduction for single
celled organisms like
bacteria.
• Many plants reproduce
asexually as well.
• Asexual offspring
(children) are identical to
their parent.
Binary Fission
• In binary fission the parent organism is
replaced by two daughter organisms,
because it literally divides in two.
• Both prokaryotes and eukaryotes
reproduce asexually through
binary fission
Prokaryotic vs. Eukaryotic
Budding
• Some cells split by budding (for example
yeast), resulting in a 'mother' and
'daughter' cell.
• Potatoes, some flowers and spider plants
reproduce by budding.
– The offspring is smaller than the parent.
Mitosis
• Mitosis is a process of cell division which
results in two daughter cells from a single
parent cell.
• The daughter cells are identical to each
other and to the parent cell.
• It is asexual reproduction.
Regeneration
Process of renewal, restoration, and growth that
makes cells able to repair themselves after
damage.
Regeneration
• Every species is capable of regeneration, from
bacteria to humans.
• Starfish are able to re-grow arms if they have
been cut off. Lizzards are able to re-grow tails.
Human Regeneration
All organisms, including humans, have the ability to
regenerate something in the body. But the process is
much more developed in lower organisms such as plants
– mammals do regenerate skin, muscle, and blood.
– other types of cells, such as those in the brain also
regenerate.
– researchers are actively working in this field to find
ways to encourage the body to regenerate organs
and limbs.
Sexual Reproduction
Creation of a new organism by
combining the genetic material of
two organisms.
Sexual Reproduction
• Sexual reproduction is the process
involving two parents.
– Their genetic material is combined to produce
a new organism different from each parent.
• All mammals reproduce sexually.
– Every person is unique.
– Even brothers/sisters are often very different
from one another.
Fraternal Twins
• Fraternal twins make up approximately 75% of the twin
population and can be boy/boy, girl/girl, or boy/girl sets.
Happen when Mom releases two eggs and different
sperm fertilize each egg.
• They do not look any more alike than typical siblings.
Maternal Twins
Occur when a single egg is fertilized which
then divides into two separate embryos.
Chromosomes
• With sexual reproduction, the offspring
inherits half their chromosomes from each
parent.
– Half the chromosomes means not all traits of
a parent will be transferred to the offspring.
More on that in the next section on inherited
traits!
Chromosomes
• Chromosomes are structures found within
the nucleus of a cell.
• They contain all the genetic information in
the form of genes.
DNA
• DNA is a long chain formation found in the
nucleus of a cell.
• It is shaped like a double-helix
• It contains all the genetic material
Donor Cells for Sexual
Reproduction
• Sperm are the reproductive cells of males.
• Eggs are the reproductive cells of females.
– Sperm and egg cells are different from all
other cells in your body because they contain
only half of your genetic information.
– 2 halves combine to make a whole new
organism!
Meiosis
One cell from each parent contributes
genetic material to produce offspring.
– Results in 2 daughter cells
– Receives ½ of genetic material from
each parent
– Produces sex cells
– You were produced by Meiosis!
Meiosis
In the diagram, the parent
cell duplicates it’s DNA then
divides. Will combine with
another parent to complete the
Process and each contribute
Half of the offspring’s DNA.