Acche Marks

Explain the process by which zygote divides and redivides to form the morula.

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After syngamy, the zygote becomes active and starts dividing. 1. Cleavage: Cleavage is the initial mitotic division of the zygote, forming a hollow multicellular blastula. Blastomeres, the cells produced, decrease in size with each cleavage due to the absence of a growth phase. As size reduces, metabolic rates increase, leading to faster successive cleavages. This demands … Read more

Describe the process of fertilization.

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Fertilization is the amazing process of combining male and female gametes to form a diploid zygote, crucial for human reproduction. This complex event usually happens in the ampulla of the fallopian or uterine tube, paving the way for the embryo’s development in the protective environment of the uterus. Sperm Movement towards Egg: The journey commences … Read more

Write a note on budding in Hydra.

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Budding is a form of asexual reproduction commonly observed in various animals like coelenterates such as Hydra and corals, as well as some colonial ascidians. In Hydra, a small outgrowth emerges at the basal end of the body, developing into a bud. This bud grows, forms tentacles, and eventually matures into a new individual. Upon … Read more

What is the difference between embryo and zygote?

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Characteristic Zygote Embryo Developmental Stage Initial single-cell stage after fertilization Advanced stage after several cell divisions; multicellular Structure Single cell containing the full set of chromosomes Multicellular with basic structures and organs starting to form Duration Starts at fertilization Follows the zygote and lasts until about the eighth week in humans

Give two differences between blastula and gastrula.

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Characteristic Blastula Gastrula Structure Hollow ball of cells, often with a blastocoel Three-layered structure with ectoderm, mesoderm, and endoderm due to gastrulation Cellular Differentiation Initial differentiation, cells maintain a more uniform appearance Significant cellular differentiation, forming distinct cell types and tissues within germ layers