Reproduction Flashcards
What is reproduction ?
Biological process where offspring are produced from parent or parents
Define asexual reproduction
Only one parent/organism that clones itself and offspring are genetically identical to parent
Define sexual reproduction
Involves two parents and combination of gametes (all offspring are unique from parents)
Why is reproduction important?
Necessary for continuity of species and is vital for evolution by natural selection
Asexual Reproduction Advantages
Reproduction is quick, no need to search for a mate and requires less energy
Asexual Reproduction Disadvantages
Genetic diseases are inherited and little to no variation of offspring (susceptible to environmental change)
Define Budding (Asexual Reproduction):
- Budding => parent forms bubble-like bud which attaches to parent while it grows and develops then breaks away
Define Binary Fission (Asexual Reproduction):
- Binary Fission => parent cell splits into two identical daughter cells
Define Fragmentation (Asexual Reproduction):
- Fragmentation => parent organism breaks into fragments and each fragment develop into a new organism
Sexual Reproduction Advantages
Provides greater variation of offspring and greater chances of species survival
Sexual Reproduction Disadvantage
Requires a mate and requires more energy
What are the 5 Kingdoms of Classification
Animals, Plants, Fungi, Bacteria, and Protists
Bacterial Traits
- Prokaryotic (no membrane-bound organelles like nucleus)
- Unicellular
What is Bacteria’s main reproduction method?
Cell Division/Binary Fission
Process of Binary Fission
- Bacterial DNA is replicated and replication occurs in both directions of the circular bacterial DNA
- Membrane pinches and 2 new cells formed
What is conjugation (Bacterial) ?
Conjugation is the non-sexual exchange/transfer of genetic material or DNA between each other
What happens during conjugation (bacterial) ?
Bacteria with certain DNA called the fertility factor use a pilus to connect to another bacterium. Once in contact, it transfers plasmid to the bacterium
What is plasmid in bacteria?
Provides extra functions, but not vital and transfer traits e.g. antibiotic resistance
Is conjugation a sexual reproduction? Why ?
No. This is because the no. of cells remains the same at the end of the process.
What are some Protist/Protista traits ?
- Eukaryotic
- Uni or multicellular but most are uni
Eukaryotes aren’t fungi, plants or animals
What are some methods of protists reproduction?
- Unicellular use budding, binary fission (asexual)
- Multicellular reproduction via. fragmentation (asexual)
Do protists reproduce via. binary fission? If so, what are the differences between bacteria?
Yes, they have a similar process, but eukaryotic protists have a nucleus, which needs to divide first.
Define multiple fission in protists ?
When the nucleus divides repeatedly before the cell splits, and the cell splits multiple times from the parent cell. Similar to binary fission, but produces more than 2 offspring.
What is budding?
Type of multiple fission, where the nucleus reproduces and smaller ‘buds’ split off the parent cell after the uneven division of cytoplasm.
What reproductive method do some multicellular algal protists use? Why?
Fragmentation. Because the algae don’t have specialized cells making it easy to break into smaller pieces and regenerate.
What are the traits of fungi?
- Eukaryotic
- Uni/Multicellular
- Heterotrophic (don’t photosynthesise)
- Decomposers of the ecosystem
How do unicellular yeasts reproduce?
Budding (asexual)
How do multicellular fungi reproduce ?
Spores (asexual)
Common reproductive method for fungi?
Spores
What is another name for spores that are asexually produced?
Mitospores
What are spores called that are sexually reproduced?
Meiospores
Can mitospores develop into an adult without fusion of another cell ?
Yes, mitospores are haploid reproductive cells and capable of developing into an adult without fusion of another cell
What allows spores to survive harsh conditions?
A layer of protective coating
What are sporangium ?
Sporangium are a cluster of spores and are released when the wall of the sporangium disintegrates
Why do fungi reproduce sexually?
Usually occurs due to adverse environmental conditions and allows for genetic variation in the population
Overview of sexual reproduction in fungi
- two haploid cells from different mycelia fuse together, where two nuclei co-exist
- haploid nuclei fuse together forming a diploid zygote
- meiosis occurs and spores are released into the environment
What is vegetative propagation?
Term describing the process where new organism results without production of seeds or spores
Example of strawberry and vegetative propagation
Strawberry plants develop a runner to move along the surface of the soil and grow a new plant once it submerges (asexual reproduction where a runner is identical to the parent plant)
How do potatoes conduct vegetative propagation?
Potato grows new plants from the eyelets of the surface of the potato
Who uses vegetative propagation and how?
Farmers/agriculturists/plant enthusiasts use more artificial ways and involve cutting parts of plants or stimulating root growth via hormones or grafting (submerging root in the substrate and allowing it to grow)
Why is asexual reproduction in plants fast?
It doesn’t require planting a seed, the seed germinating or a fragile seed growing to maturity
What is apomixis?
Asexual reproduction is where a mature plant grows from an unfertilized seed
What are petioles?
Are the structure at the base of a leaf that attaches to the stem. It can be cut here to grow another plant.
Define non-vascular plants and give an example.
A plant lacking special channels for transporting water and nutrients e.g. xylem/phloem. Examples can be mosses or liverwarts.
How do non-vascular plants reproduce?
Reproduce via. spores which develop into distinct haploid organisms before fertilisation
Define vascular plants and give an example.
Vascular plants have specialised channels e.g. xylem/phloem. Examples include ferns.
Define vascular plants and give an example.
Vascular plants have specialised channels e.g. xylem/phloem. Examples include ferns.
How many lifecycle stages do ferns have?
Ferns have 2 lifecycle stages. They produce spores which form unique structures to produce egg and sperm cells.
Summary of fern reproduction.
- Sporangium releases spores
- Spores turn into gametophytes and turns into egg/sperm cell
- Gets fertilised and forms a sporophyte
- Sporophyte develops sporangium which hangs on the underside of the fern and cycle repeats
What are gymnosperms?
Produce cones that act as their reproductive structures (no fruit protection)
Examples of gymnosperms
Cycads, conifers etc.
How do gymnosperms pollinate?
Pollinate via. wind
What is the evolutionary advantage gymnosperms have when compared to other plants?
- Don’t need to exist near water to achieve fertilisation
- Seeds provided more nourishment and protection meaning seeds can lay dormant for long periods of time before germinating
Summary of male gymnosperm sperm reproduction
- Male cone produces gametophyte (male sperm/pollen)
- Wind carries pollen to egg and fertilises the egg
- Fertilised egg develops into seed which will develop into young sporophyte
- Young sporophyte grows into adult sporophyte (tree) and produces cone
Summary of female gymnosperm egg reproduction
- Spore produces gametophyte (egg)
- Sex cell are produced in cones and is later fertilised by pollen
- Develops into young sporophyte in the seed
- Develops into an adult sporophyte (tree)
- Produces cone
What are angiosperms?
Are flowering plants producing flowers (are the reproductive structures)
How do angiosperms pollinate?
Use other organisms e.g. bird, bee, insects to serve as pollinators
How do angiosperms pollinate?
Use other organisms e.g. bird, bee, insects to serve as pollinators
What are the reproductive parts of the angiosperm called?
Stamen (male)
Pistil (female)
Can plants self-fertilise or cross-pollinate?
They can do both, but self-fertilisation is preferred for increased genetic variability
Are the male and female parts in the same plant?
Generally, but in plants, there are structures present to prevent this or even have separate male/female flowers
Is there a specific angiosperm fruit shape/size?
No, all fruits come in a variety of shapes and sizes e.g. apples, pears, grapes etc. and are all usually specialised for the kind of seed dispersal that the plant depends on