cross-pollination

Examples of cross-pollination in the following topics:

• Pollination and Fertilization

  • Plants can transfer pollen through self-pollination; however, the preferred method is cross-pollination, which maintains genetic diversity.
  • Pollination takes two forms: self-pollination and cross-pollination.
  • Because cross-pollination allows for more genetic diversity, plants have developed many ways to avoid self-pollination.
  • This allows insects to easily cross-pollinate while seeking nectar at the pollen tube.
  • Determine the differences between self-pollination and cross-pollination, and describe how plants have developed ways to avoid self-pollination

• Mendel’s Model System

  • For this reason, garden pea plants can either self-pollinate or cross-pollinate with other pea plants.
  • What's more, the flower petals remain sealed tightly until after pollination, preventing pollination from other plants.
  • A gardener or researcher, such as Mendel, can cross-pollinate these same plants by manually applying sperm from one plant to the pistil (containing the ova) of another plant.
  • When Mendel cross-pollinated a true-breeding plant that only produced yellow peas with a true-breeding plant that only produced green peas, he found that the first generation of offspring is always all yellow peas.
  • In this and all the other pea plant traits Mendel followed, one form of the trait was "dominant" over another so it masked the presence of the other "recessive" form in the first generation after cross-breeding two homozygous plants..

• The Life Cycle of an Angiosperm

  • Both anatomical and environmental barriers promote cross-pollination mediated by a physical agent (wind or water) or an animal, such as an insect or bird.
  • Cross-pollination increases genetic diversity in a species.
  • The formation of the seed completes the process of reproduction in seed plants (started with the development of flowers and pollination), with the embryo developed from the zygote and the seed coat from the integuments of the ovule.
  • Explain the life cycle of an angiosperm, including cross-pollination and the ways in which it takes place

• Reproductive Isolation

  • Reproductive isolation is a collection of mechanisms, behaviors, and physiological processes that prevent the members of two different species that cross or mate from producing offspring, or which ensure that any offspring that may be produced is not fertile.
  • In plants, certain structures aimed to attract one type of pollinator simultaneously prevent a different pollinator from accessing the pollen.
  • The tunnel through which an animal must access nectar can vary in length and diameter, which prevents the plant from being cross-pollinated with a different species .
  • Some flowers have evolved to attract certain pollinators.
  • The (a) wide foxglove flower is adapted for pollination by bees, while the (b) long, tube-shaped trumpet creeper flower is adapted for pollination by humming birds.

• Phenotypes and Genotypes

  • Mendel crossed or mated two true-breeding (self-pollinating) garden peas, Pisum saivum, by manually transferring pollen from the anther of a mature pea plant of one variety to the stigma of a separate mature pea plant of the second variety.
  • Plants used in first-generation crosses were called P0, or parental generation one, plants.
  • Mendel collected the seeds belonging to the P0 plants that resulted from each cross and grew them the following season.
  • In his 1865 publication, Mendel reported the results of his crosses involving seven different phenotypes, each with two contrasting traits.
  • Regardless of how many generations Mendel examined, all self-crossed offspring of parents with white flowers had white flowers, and all self-crossed offspring of parents with violet flowers had violet flowers.

• Mendelian Crosses

  • Mendel's crosses involved mating two true-breeding organisms that had different traits to produce new generations of pea plants.
  • Mendel performed crosses, which involved mating two true-breeding individuals that have different traits .
  • In the pea, which is a naturally self-pollinating plant, this is done by manually transferring pollen from the anther of a mature pea plant of one variety to the stigma of a separate mature pea plant of the second variety.
  • Plants used in first-generation crosses were called P0, or parental generation one, plants.
  • Mendel collected the seeds belonging to the P0 plants that resulted from each cross and grew them the following season.

• Pollination by Insects

  • Wasps are also important insect pollinators, pollinating many species of figs.
  • Moths, on the other hand, pollinate flowers during the late afternoon and night.
  • One well-studied example of a moth-pollinated plant is the yucca plant, which is pollinated by the yucca moth.
  • The shape of the flower and moth have adapted in a way to allow successful pollination.
  • Insects, such as bees, are important agents of pollination.

• Sexual Reproduction in Gymnosperms

  • Gymnosperms produce both male and female gametophytes on separate cones and rely on wind for pollination.
  • Because the pollen is shed and blown by the wind, this arrangement makes it difficult for a gymnosperm to self-pollinate.
  • Although many angiosperms are also wind-pollinated, animal pollination is more common.
  • (a) This male cone, shown in cross section, has approximately 20 microsporophylls, each of which produces hundreds of male gametophytes (pollen grains).
  • (d) This cross section of a female cone shows portions of about 15 megasporophylls.

• Pollination by Bats, Birds, Wind, and Water

  • Non-insect methods of pollination include pollination by bats, birds, wind, and water.
  • These methods include pollination by bats, birds, wind, and water.
  • Unlike the typical insect-pollinated flowers, flowers adapted to pollination by wind do not produce nectar or scent.
  • Flowers often attract pollinators with food rewards, in the form of nectar.
  • Certain orchids use food deception or sexual deception to attract pollinators.

• Herbivory and Pollination

  • This is believed to have been as much a driving force as pollination.
  • Grasses are a successful group of flowering plants that are wind pollinated.
  • Large trees such as oaks, maples, and birches are also wind pollinated.
  • Consequently, plants have developed many adaptations to attract pollinators.
  • Many bird or insect-pollinated flowers secrete nectar, a sugary liquid.