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In developmental biology, animal embryonic development, also known as animal embryogenesis, is the developmental stage of an animal embryo. Embryonic development starts with the fertilization of an egg cell (ovum) by a sperm cell (spermatozoon). [1] Once fertilized, the ovum becomes a single diploid cell known as a zygote.
Heredity of phenotypic traits: a father and son with prominent ears and crowns. DNA structure. Bases are in the centre, surrounded by phosphate–sugar chains in a double helix. In humans, eye color is an example of an inherited characteristic: an individual might inherit the "brown-eye trait" from one of the parents. [1]
The biologist Thierry Lodé proposed (2001, 2012) five modes of reproduction based on the relationship between the zygote (fertilised egg) and the parents: [1] [2]. Ovuliparity: fertilisation is external, the oocytes being released into the environment and fertilised outside the body by the male. [1]
Examples of precocial birds include the domestic chicken, many species of ducks and geese, waders, rails, and the hoatzin. Precocial birds can provide protein-rich eggs and thus their young hatch in the fledgling stage – able to protect themselves from predators and the females have less post-natal involvement.
It sounds like the setup of a wacky science fiction comedy, but this is actually real life. A five-month old baby boy was just revealed to be the first kid in the world with three biological ...
Human cultures and societies vary widely in the expression of paternal care. Some cultures recognize paternal care via celebration of Father's Day.Human paternal care is a derived characteristic (evolved in humans or our recent ancestors) and one of the defining characteristics of Homo sapiens. [19]
An important aspect of the formation of the parent offspring is the chromosome, which is a structure of DNA which contains many genes. [ 1 ] To focus more on the offspring and how it results in the formation of the f1 generation, is an inheritance called sex linkage , [ 1 ] which is a gene located on the sex chromosome , and patterns of this ...
In evolutionary biology, parental investment is the expenditure of time and effort towards rearing offspring that benefits the offspring's evolutionary fitness at a cost to parents' ability to invest in other components of the species' fitness. Parental care requires resources from one or both parents that increases the fitness of their ...