Sexual Reproduction

Cards (71)

  • Sexual reproduction - involves two separate parents that belong to the opposite sex.
  • Sexual reproduction - Both plants and animals exhibit this kind of reproduction
  • Flowering plants undergo sexual reproduction.
  • Flower - is the sexual reproductive organ in plants.
  • Flowers - often the most attractive structures of a plant.
  • Flower’s anatomy can be divided into following parts:
    • Calyx
    • Corolla
    • Androecium
    • Gynoecium
  • Calyx - green petal-like structures located right above the receptacle called the base of the flower.
  • Calyx - made up of sepals.
  • Calyx - their primary task is to safeguard the flower while it is still in the bud process.
  • Corolla - the name given to the collective colorful petals of the flower.
  • The petals of various flowers are found in different colors and are often fragrant much of the time.
  • It is the petals that attract the pollinating agents.
  • Corolla - is found above the calyx layer.
  • Androecium - the male reproductive section of a flower.
  • Androecium - it is made up of a series of stamens.
  • Each stamen at the top of it consists of a filament and anther.
  • The anthers are lobed structures that produce the male gamete-containing pollen.
  • The gynoecium is the female reproductive organ of the flower.
  • Gynoecium is composed of the ovary, style, and stigma.
  • The style is a slender filament on top of which lies the stigma that works to retain pollen grains that are transferred.
  • Once the pollen lands on the stigma, it is moved downward to the ovary via the style.
  • The ovary is lobed and composed of the female gamete-containing ovules.
  • The pollen grains and ovules by themselves cannot travel from one place to another.
  • There are other factors such as wind, water, or animals that enable the pollen grains to travel to reach the stigma of the same or another flower.
  • In plants, fertilization, which occurs after pollination and germination, is a sexual reproduction process.
     
  • Fertilization can be defined as the fusion of the male gametes (pollen) to form a diploid zygote with the female gametes (ovum).
  • Types of Fertilization
    • Porogamy
    • Chalazogamy
    • Mesogamy
    • Double Fertilization
  • Porogamy - it is the common type of fertilization carried out in all angiosperms or flowering plants.
  • Porogamy - In this type of fertilization, the pollen tube enters the ovule through the micropyle.
  • Chalazogamy - this type of fertilization is carried out on all Casuarina species of plants.
  • Chalazogamy - in this condition, the pollen tube enters the ovule through the pollen tube.
  • Mesogamy - this type of fertilization is seen in all Cucurbit plants, such as pumpkin, ridge gourds, bitter gourd and other gourd plants.
  • Mesogamy - in this type of fertilization, the pollen tube enters the ovule through its middle part or through the integuments of the ovule.
  • Double fertilization is a fertilization process characterized by the fusion of two male gametes with a female gametophyte.
  • Double Fertilization - One sperm cell in this process fuses with the egg-producing zygote, and the other fuses to create the endosperm with the two polar nuclei.
  • Both angiosperm plants undergo a dual process of fertilization.
  • In human beings, reproduction is by sexual reproduction in which both male and female gametes fertilize to give birth to a zygote that develops into an embryo.
  • Fertilization takes place within the female's body thus, called internal fertilization.
  • The penis is the male organ for sexual intercourse and urination.
  • Semen and urine leave the penis through the urethra.