Sexual Reproductions (i.e. Meiosis)
In Meiosis you have a crossing over stage in prophase I, which will result in the exchange of genetic material + the random assortment at metaphase 1 and 2 increases the variety.
There is approximately 10 billion different ways that a child can look from a mixture of the paternal and maternal genes due to all the random events that happen in meiosis/ sexual reproduction.
Answer:
Double fertilization. (Ans. 5)
Explanation:
Double fertilization is a complex fertilization process occurs only in flowering plants known as angiosperm. In this process two male gametes or sperm cells fertilization occurs, first one is fertilized with the egg and form the zygote and second one is fuses with the 2 polar nuclei which cause the formation of endosperm.
In double fertilization, after the process of fertilization, the tissue of ovary forming the fruit and fertilized ovule of an ovary forming the seed.
Answer:
Calcium
Explanation:
Parathyroid hormone (PTH) is a hormone that is secreted by the parathyroid gland. It is the major regulator of the plasma concentration of calcium ions. It regulates calcium ions in the kidney, intestine and bones.
In the kidney, is involved in the re-absorption of calcium in distal ducts and the renal collecting duct, it is also involved in activating the conversion of 25-hydroxy vitamin D into 1,25-dihydroxy vitamin D (calcitriol).
In the intestine, PTH is involved in the absorption of calcium, by increasing vitamin D production.
In the bone, it helps in regulating calcium levels; when serum calcium level is low, PTH stimulates the activity of the osteoclast, to produce more calcium.
The air diffuses into the capillaries surrounding the alveoli.
2. The pulmonary veins carry oxygenated blood to the heart.
3. Air enters the bronchioles in the lungs and reaches the alveoli.
4. The capillaries join together to reach the arteries, transferring the oxygen.
5. The oxygen-rich blood moves from the aorta and reaches the kidneys through a series of blood vessels.
6. The left atrium fills with oxygen-rich blood and contracts to fill the left ventricle.