Hint:Both these terms are related to flowers. Flowers are the reproductive parts of plants. Fertilization is facilitated between the male and the female parts of the flower by various pollinating agents.
Complete answer: Pedicel – Pedicel is the term used for a structure connecting a single flower to its inflorescence. The flowers which do not have a pedicel are termed as sessile flowers. The term pedicel is also used for the stem of the infructescence. The word "pedicel" is derived from the Latin word pediculus, which means "little foot". The stem or the branch from the main stem of the inflorescence which holds a group of pedicels is called a peduncle. A pedicel can be associated with a bract or bracts.
Petaloid – When any part of the flower is modified to look like petals, the term used for such a condition is petaloid. This modification can occur in sepals, perianth, etc. Such a modification is made by the plant in order to attract insect pollinators for pollination. The insects get attracted towards the brightly colored parts of the flower and sit on the flower to suck nectar. This process helps in the pollination of the flower.
The main purpose of a flower is to produce male and female gametes, facilitating their fertilization and production of fruit from the ovary. The main or essential parts of a flower are the male and female reproductive organs, i.e., the androecium and the gynoecium. Apart from these, the other parts are generally termed as accessory non – essential, i.e., they are not directly involved in the process of fruit formation but they assist in the process of fertilization and in protecting the essential parts of the flower. These include sepals, petals, bracts, etc.
Note: The pedicel and petaloid are also accessory parts of the flower. These are involved in holding the flower in position and in attracting pollinators respectively. Apart from this, these parts do not have any role in the reproductive process.