Definition of discoidal cleavage : meroblastic cleavage in which a disk of cells is produced at the animal pole of the zygote (as in bird eggs)
What is Meroblastic cleavage?
Meroblastic cleavage is a type of cleavage that occurs in very yolky eggs like birds in which the egg cytoplasm and not the yolk divides (incomplete division). There are two types of meroblastic cleavage discoidal and superficial. Discoidal usually occurs in birds, reptiles, fishes etc.
What does Discoidal mean?
Medical Definition of discoidal
: of, resembling, or producing a disk especially : having the villi restricted to one or more disklike areas.
What is difference between Meroblastic and Discoidal cleavage?
Meroblastic cleavage could be categorized into two sections; discoidal cleavage and superficial cleavage. During discoidal cleavage, the cleavage furrow that is developed does not penetrate the yolk.
Why is bird cleavage Discoidal?
discoidal : disc of cells is produced at animal pole of zygote. as birds has megalecicithal eggs, the yolk provides resistance to cleavage, hence the cleavage is meroblastic & discoidal.
What is Holoblastic and Meroblastic cleavage?
Holoblastic cleavage refers to the complete division of an isolecithal or mesolecithal egg into blastomeres while meroblastic cleavage refers to the incomplete cleavage in telolecithal or centrolecithal eggs resulting in unequal blastomeres.
What is Holoblastic and Meroblastic?
Holoblastic cleavage – is a complete cleavage meaning it completely penetrates the egg. Meroblastic cleavage – is incomplete or partial cleavage meaning it does not penetrate the egg completely.
What is Discoidal shape?
2 : flat and circular like a disc.
What was a Discoidal used for?
The discoidal, also called a chunky stone, was the centerpiece in the competitive game of Chungke. The stone disc is circular in shape with variation in size and color. Engravings on game pieces were common, often including circles, dots and linear patterns.
How do you say Discoidal?
Quote from video on Youtube:De escoger de escuela de escoger o des cuero dios cuero.
What is a spindle shape?
Definition. adjective. Having a shape like a spindle, that is being wide in the middle then tapering at both ends. Supplement.
What is elongated shape?
If you take a rectangle or a circle and stretch it out, you end up with an elongated shape called an oblong. If you stretch a circle until it becomes an oval, you’ve made it oblong.
What is a biconcave shape?
A biconcave disc — also referred to as a discocyte — is a geometric shape resembling an oblate spheroid with two concavities on the top and on the bottom.
What is an Indian Discoidal?
A discoidal is a round Mississippian game stone that was used in the ancient Native American game known as chungke or chunkey. They are found throughout the southeastern and midwestern United States.
What are Nutting stones?
Nutting stones are a fairly common artifact found throughout most of Georgia. These are unusually shaped stones with one or more shallow cupped spots on one or more surfaces (top). It is assumed that these impressions of multiple sizes were for the cracking of hard shelled nuts like walnuts or hickory nuts.
How were chunky stones made?
Archaeologists have found disc-shaped stones among the remains of ancient Native American villages in Illinois. Based on close inspection of the objects, it appears that artisans shaped granitic rock with a stone hammer, slowly removing small bits of stone until they created the desired size and shape.
How old are Nutting stones?
4,000 to 8,000 years old
These two nutting stones were found in the Sahara Desert and archeologists date them as being 4,000 to 8,000 years old.
What is an Indian celt?
celt, characteristic New Stone Age tool, a polished stone ax or adz head designed for attachment to a wooden shaft and probably mainly used for felling trees or shaping wood.