Cell Division - 16.4 Flashcards
What is the key mechanism involved in asexual reproduction?
Mitosis
What is binary fission?
When Bacteria replicates its DNA and distributes a complete copy of its DNA to two identical daughter cells
Which types of organisms undergo binary fission?
Bacteria and Prokaryotes (fungi and algae)
Does bacteria undergo mitosis?
No, binary fission
How fast can bacteria divide?
In favorable conditions as little as 20 minutes
What is a disadvantage of binary fission?
If once cell is vulnerable to a toxin or virus the rest of the colony will be vulnerable to the same thing
What is conjugation?
The transfer of genetic material from one cell to another by cell to cell contact through a bridging structure (pilus).
What is a pro of conjugation?
It creates cells with genetic combinations - provides chance for cells that may be better adapted to the environment
What can conjugation only take place between?
To non identical bacterial cells
What is budding?
A form of asexual reproduction in which a complete but miniature version of the parent grows out of the parents body
- The new organisms then seperates to become an independant organism
What organism undergoes budding?
A hydra
What is vegetative reproduction?
When stems from one organism extends for a new plant to develop from them
What is fragmentation?
New plant that is grown from a fragment, or tuber from the parent plant
What is parthogenesis?
When an unfertilized egg develops into an adult
What is a spore?
A structure that contains genetic material and cytoplasm surrounded by a protective sheath wall
How are spores transported?
By wind and water
What is the diploid generation of plants?
Sporophytes
What is the haploid generation of plants?
Gemetophyte
Which generation is dominant vascular plants?
Diploid sporophytes
Which generation is dominant in non vascular plants?
Haploid gametophytes
Which generation is dominant in ferns?
Sporophyte generation
What generation is dominant in mosses?
Gametophyte generation
What generation is dominant in conifers?
Sporophyte generation
Which animals alternate between asexually reproducing and sexually reproducing?
Phylum cnidaria - jellyfish, sea anemones, and corals
What is the two forms that the cycle of the Cnidaria is divided into?
- Non motile polp
*Free swimming medussa
What is the life cycle of a jellyfish?
Medussa stage is dominant of exclusive
What is the life cycle of a sea anemonea?
Polyp stage is dominant or exclusive
What is the life cycle of an obelia?
Alternates regularly between asexual poly and a sexual medusa form
What are three advantages of asexual reproduction?
- Species can better adapt to environment
- Less competition among siblings
- Homologous chromosomes and crossing over gives opportunities to replace or repair damaged chromosomes
