Download Asexual vs Sexual Reproduction

REPRODUCTION
CHAPTER 11.1
RECALL THE TWO IMPORTANT
QUESTIONS WE ASKED….
• What is the significance of
Mitosis?
• Why do Chromosmes come in
Pairs?
ASEXUAL VS
SEXUAL
REPRODUCTION
CHARACTERISTICS OF:
ASEXUAL REPRODUCTION
• One Parent
• Genetic Continuity – Identical
Offspring
• Many Offspring – Quickly
• Less Maturation Time
• Nuclear Division = MITOSIS
TYPES
OF
ASEXUAL
REPRODUCTION
BINARY FISSION
(SPLITTING IN TWO)
FRAGMENTATION - (PIECES)
• Fragmentation- A kind of reproduction
where the “body” breaks into several
pieces and the pieces develop into
complete adults.
FRAGMENTATION - (PIECES)
B
U
D
D
I
N
G
BUDDING
• New individuals split off of the original
organism.
CYTOPLASM
DIVIDES
UNEQUALLY
MULTICELLULAR BUDDING - SPONGE
PARTHENOGENESIS
Parthenogenesis
= a process in
which a female
produces an egg
that develops
into an adult
without ever
being fertilized.
CLONING
MORE ABOUT CLONING
DURING CHAPTER 15!
SEXUAL
REPRODUCTION
• Requires two parents (cells)
• Union of special cells called GAMETES
• Sperm and Eggs or pollen and ovum
• Provides GENETIC VARIATION
• Usually mature more slowly
TYPES OF GAMETES
EGG & SPERM
POLLEN & OVUM
SEXUAL REPRODUCTION
Advantages:
• Genetic variation
• Genetically diverse populations are able to
withstand changes and disease better.
Disadvantages:
• Need to expend energy looking for mate
• Produce fewer offspring.
HERMAPHRODITES
• Organisms with
ovaries and testes
• Produce both eggs
and sperm.
EARTHWORMS HAVE TESTES AND
OVARIES
CHROMOSOME REVIEW
• A chromosome is
an X shaped
object that
contains DNA.
• Within the DNA
lies the codes for
every
characteristic of
a living thing.
CHROMOSOME REVIEW
• Every chromosome
consists of two
identical halves
called “sister
chromatids”
• The chromosome
has a backup copy
of the DNA.
CHROMOSOMES
• Genes are located
on located on
chromosomes.
• Each chromosomes
contains thousands of
genes.
• A gene controls a
specific trait such as
your height or hair
color.
CHROMOSOME NUMBERS
• Every species has a
specific number of
chromosomes.
• Humans have 46
chromosomes or 23
pairs of
chromosomes.
CHROMOSOME NUMBERS
• Mosquitos have
only 6
chromosomes in
each cell.
• How many pairs of
chromosomes
does a mosquito
have?
HAPLOID VS. DIPLOID CELLS
• Diploid cell- A cell that has two copies of
each chromosome.
• This would include all somatic/body cells
• New cell will have an identical copy of
DNA
• Diploid cells are produced by mitosis
• Mitosis is an asexual process.
• We call these cells “2N” cells.
• Examples would include: liver cells, etc.
HAPLOID VS. DIPLOID CELLS
• Haploid cells- Have only one (half) set of
chromosomes.
• This includes ONLY GAMETES (egg/sperm).
• The two gametes will combine to create a
new organism with full set of chromosomes
(half from mom, half from dad).
• Haploid cells are created through meiosis.
• Meiosis is a sexual process.
• We call haploid cells “1N” or “N”
HAPLOIDS VS. DIPLOID CELLS
SPECIES
HAPLOID (N)
DIPLOID (2N)
HUMANS
23 (# chromosomes in
sperm/egg)
46 (# chromosomes in
somatic/body cells)
MONKEY
CORN
42
10
CATS
FRUIT FLY
38
4
HOMOLOGOUS CHROMOSOMES
• Homologous chromosomes- Each diploid cell has a
pair of chromosomes known as homologous
chromosomes.
• They are similar in shape size and genetic make-up.
• In each homologous pair one chromosome came
from your mother and one from your father.
HOMOLOGOUS PAIRS
AUTOSOMES VS. SEX CHROMOSOMES
• Autosomes- Chromosomes with genes that
do not determine the sex of an individual.
• Sex chromosomes- Chromosomes that do
determine the sex of an individual.
AUTOSOMES VS. SEX CHROMOSOMES
Sex chromosomes
(Female)