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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Answer:
Cells of skin, for instance, have highest mitotic index.
Explanation:
Many cells are capable of dividing rapidly. <u>For example</u>, in plants, the cells near the root tip in the apical meristem divide rapidly to push through the soil because the root cap detects the gravity and direct rapid division and growth of cells near the tip.
If we take muscle, skin, kidney, and lung as examples that are given in real question, <u>skin cells have the highest mitotic index because they need to get replaced most frequently</u>.
One of the exceptional psychosocial undertakings among ages 2 and 6 is emotional regulation. In addition, emotional regulation of emotion is the capability to react to the continuing loads of involvement with the variety of emotions in a way that is communally tolerable and adequately supple to permit impulsive responses as well as the capability to delay impulsive responses as needed.
Answer:
1. The cells in our bodies are surrounded by these types of solutions. → Isotonic solution.
3. When an animal cell is places in this solution, it will burst (get layer) → Hypotonic solution.
4. When an animal cell is placed in this solution, it will shrivel or shrink (get smaller) → Hypertonic solution.
5. This is a solution with more solute than the cell. Hypertonic solution.
Explanation:
The cells in the body are in a balance of substances —concentration of solutes— between their cytoplasm and the extracellular space. This balance is dynamic in living beings, due to the constant exchange of ions and substances between the intracellular and extracellular space. For this reason, the extracellular medium is isotonic with the cytoplasm.
<u>A cell can lose or gain water depending on the amount of solutes that a medium has in which it is found</u>, with respect to the cytoplasm. This difference in solutes concentrations produces an osmotic gradient that drags water from the least concentrated solution to the most concentrated, through the process of osmosis, which seeks to achieve an equilibrium of concentrations.
- <em>When a animal cell is exposed to a </em><em>hypertonic solution</em><em> </em>—<em>with a higher concentration of solutes</em>— <em>it loses water and tends to </em><em>dehydrate and become smaller</em><em>.</em>
- <em>An animal cell in a </em><em>hypotonic solution</em><em> receives water, so it can </em><em>expand and even burst</em><em>.</em>
In practice, the concentrations of intracellular and extracellular solutes depend not only on the osmotic gradient, but also on the concentration gradient of substances.
Answer:
Which of the following statements about the biosphere is NOT true?
Matter is constantly added to the biosphere.
Explanation:
Biosphere is a system closed to matter so it is not constantly added to biosphere