Reproduction in Organisms Test 7

varies develop into fruits which further develop a thick wall covering called the pericarp. The major function of the pericarp is protection. After fertilization all flower parts wither and fall off.

Zygote develops into an embryo. It happens through a series of cell division and cell differentiation. In case of flowering plants, the zygote develops into an embryo and the ovule develops into a seed.

In flowering plants, the zygote is formed in the ovule. The pollen tube is a mode of transportation for the pollens that lay on the stigma, to the ovaries. Anther consists of pollen grains (male gamete).

Since zygote development takes place inside the female body, they are in a protected environment. Unlike the oviparous animals, which are vulnerable. The chances of oviparous animals to survive is low.

Animals are categorized into 2 types of–oviparous and viviparous. Viviparous animals are those animals in which zygote development takes place within the body itself. Mammals are a very good example for viviparous reproduction.

Animals are categorized into 2 types of–oviparous and viviparous. Oviparous animals are those animals in which zygote development takes place outside the body. Reptiles and birds are examples of oviparous animals.

Embryogenesis is the process of embryo formation from a zygote. It undergoes mitosis and cell differentiation in this process. Cell differentiation helps in categorizing cells into specialized tissues.

Organisms having haplontic lifecycles, zygote divides by meiosis to form haploid spores that grow into haploid individuals. Formation of zygote forms the vital link, ensuring continuity of the species.

Sexual reproduction is divided into 3 events. Pre-fertilization, fertilization and post-fertilization events. Pre fertilization is the events occurring before fusion of gametes (gametogenesis), fertilization is the fusion of gametes to form zygote and post-fertilization are the events occurring after zygote formation.

Since there is no fertilization of gametes taking place, there is no crossing over of genes taking place. This hence causes no variations in the generations. This makes it difficult for the offspring to adapt to the changing environmental conditions.