when is meiosis 2 completed for an egg? course hero

by Jocelyn Runolfsson Published 2 years ago Updated 1 year ago 10 min read

After ovulation the oocyte is arrested in metaphase of meiosis II until fertilization. At fertilization, the secondary oocyte completes meiosis II to form a mature oocyte (23,1N) and a second polar body.Jan 10, 2000

What happens during meiosis?

In males meiosis II is completed in the and in females meiosis II is completed from BIOLOGY 123 at STEM School Egypt. ... Twins produced when a single egg is fertilized are called _____ twins, ... Course Hero member to access this document. Continue …

What is the difference between meiosis and haploid?

View full document. Meiosis is the formation of egg and sperm cells. In sexually reproducing organisms, body cells are diploid, meaning they contain two sets of chromosomes (one set from each parent). To maintain this state, the egg and sperm that unite during fertilization must be haploid, meaning they each contain a single set of chromosomes.

How many types of meiosis are there?

Egg production Meiosis 1 completed during egg maturation Meiosis 2 completed triggered by fertilization ovulation ... Course Hero is not sponsored or endorsed by any college or university. ...

What type of cell division occurs during meiosis?

2. A cell with only one of set of chromosomes is called [ diploid / haploid ] cell. These types of cells are found in the reproductive organs and are called [germ / somatic ] cells. 3. Sperm and egg cells are called [gametes / zygotes ]. A fertilized egg is a [ gamete / zygote]. 4. A type of cell division that results in diploid cells ...

Where does meiosis 2 occur during oogenesis?

The final phase of oogenesis includes the second phase of meiosis (meiosis II) during which the secondary oocyte, or mature egg cell, is produced. This stage occurs after puberty. All three phases of oogenesis occur within the ovary.Sep 8, 2010

What stage of meiosis is an ovulated egg in?

second meiotic metaphase

The ovulated egg is in second meiotic metaphase when it is released (Figure 19.24).

What is Stage 2 of meiosis?

During meiosis II, the sister chromatids within the two daughter cells separate, forming four new haploid gametes. The mechanics of meiosis II is similar to mitosis, except that each dividing cell has only one set of homologous chromosomes.

Where does meiosis 2 occur in females?

Meiosis II occurs in the secondary oocytes. Meiosis II is arrested at the metaphase II stage and is only completed after the penetration of sperm into the ovum.

Does meiosis 2 happen after fertilization?

At fertilization, the secondary oocyte completes meiosis II to form a mature oocyte (23,1N) and a second polar body.Jan 10, 2000

Does meiosis occur after fertilization?

1 Answer. Meiosis occurs before fertilization.Mar 11, 2018

What are the four stages of meiosis 2?

Sister chromatids separate during a second round, called meiosis II. Since cell division occurs twice during meiosis, one starting cell can produce four gametes (eggs or sperm). In each round of division, cells go through four stages: prophase, metaphase, anaphase, and telophase.

How many stages does meiosis 2 have?

In meiosis II, the phases are, again, analogous to mitosis: prophase II, metaphase II, anaphase II, and telophase II (see figure below). As shown in the figure below, meiosis II begins with two haploid (n = 2) cells and ends with four haploid (n = 2) cells.

What is the result at the end of meiosis 2?

In meiosis-II the separation of two chromatids occur so that equal number of chromatids (in fact chromosome due to duplication of genetic material) goes to each of the daughter cell. Thus, at the end of meiosis-II, four daughter cells are formed. Each cell has half the number of chromosomes present in the diploid cell.Feb 26, 2018

At what point is meiosis II completed for the female gamete?

The answer is c) fertilization. The female gamete stays locked in metaphase II until fertilized by the male gamete.

What is the trigger that leads the oocyte to complete meiosis 2 and becoming an egg?

Fertilization

(A) Fertilization induces the transition from metaphase II to anaphase II, leading to completion of oocyte meiosis and emission of a second polar body (which usually degenerates).

Does meiosis occur in egg cells?

Both males and females use meiosis to produce their gametes, although there are some key differences between the sexes at certain stages. In females, the process of meiosis is called oogenesis, since it produces oocytes and ultimately yields mature ova(eggs).Mar 24, 2011

What is meiosis in biology?

Meiosis. What a funny word with so many vowels. Well, this is a really important part of human biology and the biology of many other organisms that go through sexual reproduction. Basically, here's the problem: You've got a certain number of chromosomes; we humans have 46. But a child who's going to get half of their inheritance from their mother and father, they can't get 46 from both of them--that would be 92. So there has to be a way to take those paired chromosomes and break them apart in order to make gametes; sperm and eggs. That's what meiosis is all about. It's taking that complete set and breaking it down to a so-called haploid set and also providing the opportunity for recombination to occur to sort of scramble the copies and produce new kinds of outcomes, which is critical for the diversity of a species. Meiosis is one of those things that's hard to really get your mind around. There's meiosis 1, there's meiosis 2...you have to learn where the recombination occurs, but it is a really exciting part of human biology.

What happens to the sperm during meiosis?

To maintain this state, the egg and sperm that unite during fertilization must be haploid, meaning they each contain a single set of chromosomes. During meiosis, diploid cells undergo DNA replication, followed by two rounds of cell division, producing four haploid sex cells.

How many chromosomes are there in meiosis?

Well, this is a really important part of human biology and the biology of many other organisms that go through sexual reproduction. Basically, here's the problem: You've got a certain number of chromosomes; we humans have 46 .

Why is meiosis II right over here?

This right over here is meiosis II because it preserves the number of chromosomes, just like mitosis. So this is meisosis, meiosis II right over here. We started with a haploid number and we finished with a haploid number just like this, and now these gametes are ready for some fertilization.

What happens in metaphase II?

And actually all of meiosis II is very similar to what happens in mitosis. So in metaphase II, our centrosomes have migrated to the poles. So our centrosomes have migrated to the poles.

What happens during interphase?

Interphase takes place between two meiotic divisions. The same way it duplicates in the mitosis - during interphase. So, after meiosis I, interphase takes place and S phase during which centrosome is duplicated. Shortly after proceeds prophase II. Now you have two centrosomes.

Do centrosomes migrate to the opposite end of the cell?

So the centrosomes have replicated and they will start to migrate to opposite ends of the cell. So once again, very strong analogy, especially to frankly, prophase from mitosis. So now let's keep going. We're now ready to go to metaphase II.