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3 years ago

Use the table below to organize these events in order of their occurrence. Place each one in its correct stage of development.

1 answer:

6 0

Presented below we have the story of the embryonic development.
Firstly, a sperm cell fertilizes the egg and implantation takes place in the uterus. At this stage the embryo is made only out of one cell called the zygote. after the implantation cells divide. With each division the number of cells duplicate. At the stage of 16 <span>cells </span>a solid structure called morula forms. Up to this point all of the cells have been dividing equally forming a symmetrical structure, but at this point, the cells start to organize into a fluid-filled blastula. The blastula has an opening, called a blastopore. Further divisions of the cells of the blastula result in the formation of The three germ layers: ectoderm, mesoderm, and endoderm.
These three layers will develop into all of the different tissues and structures of the organism. The first functional organ to form is the heart, which forms around the third week of embryonic development. At his point the heart begins to beat with the embryo’s own blood, often a different type than
the mothers'.

Quickly after that, the nervous system starts to develop and portions of the brain forming the right and left cerebral hemispheres appear. The nervous system is then developed further, formin the structures that will form the 5 parts of the brain. In this process, the cerebral hemispheres become the largest parts of the brain. The embryonic development finishes with the forming of all of the organs and tissues of the organism and the birth.
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What is the name of the groove that forms in the middle of a dividing plant cell

mrs_skeptik [129]

Plants have cell walls, so cytokinesis cannot go on with a cleavage furrow, but instead, a cell plate forms across the cell in the location of the metaphase plate.

There is no distinct groove along the cell plate as the cell divides because of the rigid nature of the cell plate or new cell wall.

A plant cell divides differently from an animal cell which forms a clear cleavage furrow because it only has a flexible cell membrane and not a rigid cell wall like plants.

The cell plate in plant cells is formed by membrane bound vesicles which migrate to the center of the cell where the metaphase plate used to be and fuse together to form a cell plate.

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3 years ago

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Lelu [443]

The best kind of model for the scientist to use is an interactive model of the planets' orbits on a computer.

<h3>What is the law of orbits?</h3>

Kepler's first law, also known as the law of orbits, describes the shape of planetary orbits. According to this law, the planet's orbits around the Sun are elliptical, despite having very small eccentricities.

For this reason, it is necessary to know all the orbits of the planets in an interactive way, since according to Kepler's law, the orbits decrease over time.

See more about orbits at brainly.com/question/18914648

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2 years ago

Q - Describe the Mitoses with the help of diagram. write its different phares and explain them.

bonufazy [111]

Answer:

Mitosis is a type of cell division in which single haploid cell (n) or diploid cell (2n) divides into two haploid or diploid daughter cells that are same as the parent.

Mitosis occurs in somatic cells of plants and animals. In this cell division, the two daughter cells have the same number of chromosomes as that in the parent cells.

Mitosis consists of four basic phases: prophase, metaphase, anaphase, and telophase.

1.Prophase:-

It is the first visible stage in karyokinesis. The chromosomes appear as long coiled threads called chromatids. The chromatin becomes shorter, thicker and visible due to the condensation of DNA. The chromatins are now called chromosomes. Stainability of nucleus increase. Each chromosome starts to splits longitudinally into two sister chromatids. These sister chromatids are attached to each other at the centromere. The nuclear membrane and nucleolus start to disappear and by the end, it will be completely disappeared.

ii. Metaphase:-

Nuclear membrane and nucleolus completely disappears and simultaneously appearance of spindle fibers. Spindle fibers are attached to the centromere of a chromosome. The chromosomes are arranged on the equatorial plane. The process of gathering of chromosomes in equator is called congressional and plate formed is called metaphasic plate.

iii. Anaphase:-

The centromere of each chromosome splits into two sister chromatids and forms two daughter chromosomes. The daughter chromosomes are pulled towards the poles due to the contraction of spindle fibres and stretching of interzonal fibers. During polar movement, the chromosomes show different shapes i.e. J, U, V, L or I shaped in appearance. At the end of anaphase, each pole will get one set of daughter chromosomes. It is the shortest phase and is also known as a migratory phase.

iv. Telophase:- The daughter chromosomes reach respective poles and uncoil and become thin, long and visible. The spindle fibres start disappearing and finally disappear. The nuclear membrane and the nucleolus reappear.

Two nuclei are formed at the end of telophase. Both the nuclei have the same number of chromosome as the parent cell. It is the last visible stage of karyokinetic and is also known as reorganization phase.

It is followed by cytokines or division of cytoplasm.

Explanation:

5 0

2 years ago

What is the process of maintaining a constant internal environment called

Jobisdone [24]

It is called the homeostasis.

Homeostasis is the living organism's mechanism to maintain and sustain its internal environment at the level where it will suffice for them to survive. This process involves the pulling and pushing of delinquencies and extremities with an organism.

6 0

4 years ago

Read 2 more answers

A scientist adds a chemical to a dividing plant cell that keeps the cell plate from forming during cytokinesis. The chemical doe

Vadim26 [7]

Answer:

Loss of cell plate formation and production of multinuclear monads.

Explanation:

The inhibition of cell-plate formation during cytokinesis will inhibit the development of the phragmoplast which function as a scaffold for cell plate assembly and this will not allow for the formation of a new cell wall needed to separate the two new daughter cells leading to loss of cell plate formation and giving rise to multinuclear monads.

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4 years ago