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Diagram of the six types of shift in heterochrony, a change in the timing or rate of any process in embryonic development.Predisplacement, hypermorphosis, and acceleration (red) extend development (peramorphosis); postdisplacement, hypomorphosis, and deceleration (blue) all truncate it (paedomorphosis).
Diagram of stages of embryo development to a larval and adult stage. 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]
A puppy is a juvenile dog, generally one less than 12-18 months old. Puppies are markedly underdeveloped and dependent on their mothers at birth (displaying altriciality), but healthy puppies grow quickly and begin walking thereafter. Puppies generally weigh 8–16 oz (0.23–0.45 kg) shortly after birth, depending on the breed. [1]
Plant development is the process by which structures originate and mature as a plant grows. It is studied in plant anatomy and plant physiology as well as plant morphology. Plants constantly produce new tissues and structures throughout their life from meristems [ 35 ] located at the tips of organs, or between mature tissues.
The neural fold is a structure that arises during neurulation in the embryonic development of both birds and mammals among other organisms. [1] [2] This structure is associated with primary neurulation, meaning that it forms by the coming together of tissue layers, rather than a clustering, and subsequent hollowing out, of individual cells (known as secondary neurulation).
In the video, Oakley, a German Shepherd who still looks very much like a puppy himself, is “teaching” his infant sister Junie how to climb a steep set of stairs at their house. Well, either ...
Prenatal development (from Latin natalis 'relating to birth') involves the development of the embryo and of the fetus during a viviparous animal's gestation. Prenatal development starts with fertilization , in the germinal stage of embryonic development, and continues in fetal development until birth .
A marsupial has a short gestation period, typically shorter than its estrous cycle, and gives birth to an underdeveloped newborn that then undergoes further development; in many species, this takes place within a pouch-like sac, the marsupium, located in the front of the mother's abdomen.