9A. Asexual vs Sexual Reproduction Flashcards
Gene pool is
all the genes and alleles present in a population.
The more alleles in the gene pool
the higher genetic diversity.
The broader a population’s gene pool
the higher its chances of survival.
Most eukaryotic species employ sexual reproduction as
a reproductive strategy to produce genetically varied offspring
Sexual reproduction is
the union of two haploid gametes (fertilisation). Results in a genetically unique diploid zygote.
Viviparity happens
After a time of gestation, the embryo develops inside the mother’s body and is born.
Oviparity happens when
The embryo develops from nutrients contained within the egg yolk, which is discharged into environment.
Why won’t all species animal or plant reproduce in the same way.
Because of the species’ environmental stresses
Pollination happens when
Pollen is present. Happens in plants.
How does Pollination happen
The embryo that develops becomes a seed, which contains nutrients. From there, an immature plant begins growing into a new plant.
Asexual Reproduction
is
the reproduction without the fusion of gametes and no mate is required.
All offspring or daughter cells of asexual reproduction are
genetic clones of each other and of the parent.
Binary Fission
Prokaryotic organisms can reproduce rapidly by growing and dividing in two.
Budding and Fragmentation occurs in
simple eukaryotes
Budding
A bud forms due to increased cell growth and breaks away from main organism then develops into a separate organism. Has identical DNA.
Vegetative propagation
Plants reproduce without seeds. A vegetative section of the plant breaks away from the original plant and independently growing into a new plant.
Fragmentation
Parent breaks into separate fragments, each can independently developing into a separate organism.
Advantages of sexual reproduction
- increases genetic diversity
- improves disease-resistance
- reduces risk of offspring developing a genetic disorder
Disadvantages of sexual reproduction
- cost of male progeny
- time it takes
- risk of transferable disease during sexual intercourse
- risk of losing offspring to outside influences
Advantages of asexual reproduction
- population grows faster
- identical clones to the parent
- doesn’t require a mate to reproduce
- requires little parent investment
Disadvantages of asexual reproduction
genetic diversity is low
Sporogenesis occurs in
many plants, as well as fungi, algae, and moulds.
Sporogenesis
Small haploid units that form on the surface of organism are formed and are released into surroundings. When they land they may then grow into a larger organism.
Parthenogenesis is a
rare process of asexual reproduction
Parthenogenesis involves
the development of an embryo without the need for a male gamete to fertilise the egg.
Parthenogenesis results in
eggs that are produced via mitosis and develop into a new organism that is identical to the female parent.
