the main advantage of asexual reproduction, in addition to its speed, is that it permits the propagation of advantageous genetic makeups since the offspring are genetically identical with the parent
sexual reproduction, on the other hand, permits new combination of traits to arise from the contributions of multiple different ancestors
certain plants produce body parts specialized for breakaway and dispersal that are known as propagules
in grafting, the plant that is to be asexually proparagated is known as the stock; this is atteched to the scion, which may be little more than a root. It is important that the two have their cambium layers in contact with each other
the production of pollen by the seed plants largely circumvents the requirement found in ferns, mosses, and the like for water as a requirement for fertilization
the type of reproduction in which an animal divides into several pieces and then each piece develops into an entire new animal is called fragmentation
in metagenesis there is an alternation of asexual and sexualgeneration
parthenogenesis is a type of reproduction in which an unfertilized egg develop into a new individual
an individual that can produce both eggs and sperm is described as hermaphroditic
a sex cell (either egg or sperm) is properly called a gamete; a fertilized egg is a zygote
reproduction - biological process by which "offspring" are produced from their parent or parents
two main types of reproduction
sexual
asexual
asexual reproduction - also called vegetative reproduction
asexual reproduction - usually involves only the plant's vegetative structure like roots, stem, and leaves
sexual reproduction - use of sex cells (gametes)
sexual reproduction - involves the fusion of male and female gametes to form zygote
sexual reproduction - genetic variability
sexual reproduction - two parents
sexual reproduction - fusion of gametes
sexual reproduction - parent and offspring are not identical
sexual reproduction - variation is present in the same species
asexual reproduction - one parent only
asexual reproduction - no gametes are produced
asexual reproduction - parent and offspring are identical
asexual reproduction - no variation
types of asexual reproduction
binary fission
budding
fragmentation
parthenogenesis
metagenesis
vegetative reproduction
sporogenesis
binary fission - separation of the body into two new bodies
binary fission - common in single celled organisms
budding - a new organism develops from as an outgrowth from the parent body known as bud
budding - once grown, the new organism detaches from the parent body
fragmentation - the parent body breaks into several pieces where each piece grows into a new individual
parthenogenesis - the female gamete develops into the offspring without being fertilized by a male gamete
metagenesis - reproduction characterized by the alternation of a sexual generation and a generation that reproduces asexually
metagenesis - alternation of generations
vegetative reproduction - a plant such as stems, leaves, roots or turions are used to reproduce new plants
sporogenesis - formation of spores from sporangia, which themselves are reproductive cells
flower - reproductive shoots of the angiosperm sporophyte
flower is composed of four whorls of highly modified leaves called flower organs:
sepals
petals
stamens
carpels
a stamen consists of a stalk called the filament and the terminal structure called the anther; within the anther are chambers called pollensacs, in which pollen is produced
a carpel has an ovary at its base and a long, slender neck called the style. At the top of the style is the sticky structure called the stigma that serves as a landing platform for pollen.