Sexual and Asexual Reproduction

• Reproduction is how organisms produce offspring

Types of Reproduction

• Sexual Reproduction involves two parents
• Sexual Reproduction involves the presence of gametes
• Sexual Reproduction results in offspring that are genetically are hybrids of parents
• Asexual Reproduction involves one parent
• Asexual Reproduction does not needs gamete union
• Asexual Reproduction results in offspring that are genetically identical to parent (Clone)

Sexual Reproduction

• Involves the fusion of gametes from the male and female organism
• Results in genetically diverse individuals, as the individual's genetic make-up is different from its parents

External Fertilization

• Takes place outside the female body
• Commonly happens through spawning, where eggs are released by a female, and sperm is released in that area by a male, at the same time

Internal Fertilization

• Takes place inside the body of the female
• Happens due to direct introduction of sperm cells by a male organism in the female reproductive tract

Oviparity

• A type of internal fertilization
• Fertilized eggs are laid outside, where they receive nourishment from the yolk.
• Snakes and Lizards are examples of animals that use this approach

Ovoviviparity

• A type of internal fertilization
• Fertilized eggs are retained in the female's body
• The embryo obtains its nourishment from the egg's yolk.
• Seahorses are an example of animals that use this approach

Viviparity

• A type of internal fertilization
• The offspring are born directly, not via a hatching egg
• Offspring receive nutrition directly from the mother via a placenta
• Horses and dogs are examples of this

Hermaphroditism

• The condition of having both male and female reproductive organs

Sequential Hermaphroditism

• An individual is born of one sex but can later change into the opposite sex
• Some fish species develop first as male and then switch to female

Simultaneous Hermaphroditism

• An individual has both male and female reproductive system at the same time
• Earthworms are an example of this

Asexual Reproduction

• Reproduction in which a new offspring is produced by a single parent
• No fusion of gametes involved to create the offspring or new individual
• Common in prokaryotic microorganisms and in some eukaryotic and multi-celled organisms

Fission

• Fission occurs after a mitotic division of the nucleus
• The parent cell splits into two equally sized daughter cells, forming a new organism.

Budding

• The new individual arises from an outgrowth or bud from the parent
• The bud will acquire nutrition from the parent
• The bud grows and develops until it matures
• Eventually, it detaches from the parent body.

Fragmentation

• It occurs in multicellular organisms
• The body of the organism breaks into two or more parts
• These parts will regenerate on their own, forming new organisms

Spore Formation

• Spores are reproductive cells that are capable of giving rise to a new organism
• When a spore lands on a suitable environment, it will generate a new fungus

Parthenogenesis

• An unfertilized egg develops into a new individual
• This new individual is a clone of the parent
• The resulting organisms can be either a diploid or a haploid, depending on the process and species

Development

• Is the process of how an organism changes over time
• Development moves an organism from being a single cell to a mature organism

Gametogenesis

• Creation of gametes, or sex cells, happens through meiosis
• Spermatogenesis happens in the seminiferous tubules; testes
• Oogenesis happens in the ovaries

Fertilization

• A sperm cell from one parent fertilizes an egg cell from the other parent
• Sperm and egg unite in one of the fallopian tubes to form a zygote

Embryo Development

• The fertilized egg, called a zygote, develops into an embryo

Stages of Human development

• Four main stages: Infancy, Childhood, Adolescence, Adulthood