Answer:
30
Explanation:
The seed of an angiosperm is formed as a result of fertilization (fusion of sperm in pollens and the ova from ovary). According to the question, the cells of the seed which will grow into the plant contains 20 chromosomes. Seeds of angiosperms contain a tissue called ENDOSPERM that forms as a result of the unique DOUBLE FERTILIZATION in angiosperms. It occurs when one haploid sperm cell fuses with two haploid polar nuclei to form a triploid endospermic structure that serves as food for the growing embryo in the seed.
Now based on the above explanation, the diploid plant cell with 20 chromosomes will have 10 chromosomes (half as much) in its gametes as a result of meiosis. This 10 chromosomes in each gamete (sperm and ovum) fuses to form a diploid zygote with 20 chromosomes, while one haploid sperm cell (10 chromosomes) also fuses with two haploid polar nuclei (10 chromosomes each) to form a triploid endosperm with 30 chromosomes i.e. 10+10+10.
<em>sieve tube elements are the cells of phloem which allow transportation of photosynthates through phloem...
<u>
how sieve tube elements form sieve tubes:
</u>sieve tube elements are connected end to end and form a long chain which is called sieve tube,,,,
sieve tube elements are connected with the help of a side chain with the help of peptide bond...also one element has tapering end which easily overlaps with other end of next element to form sieve tube,,,,</em>
The cell membrane folds upon itself easily, which facilitates cellular reproduction by mitosis.
<span>The membrane is a flexible, fluid mosaic and changes shape easily to create holes for substances to move in and out of the cell. </span>
<span>The outer layer of the membrane is hydrophilic, which allows water to flow in and out of the cell easily to eliminate waste. </span>
<span>The proteins that are embedded in the cell membrane act as channels to transport substances in and out of the cell.</span>
Answer: blood calcium level
Explanation:
There are several factors affecting the rate of kidney filtrate formation including filtration membrane integrity
, systemic blood pressure, and renal artery/arteriole diameters.
Filtration membrane integrity
: It regulates the filtration of small fitrates and large filtrates. It is very important to handle the osmotic pressure of salts, if it will get damage the filtration will not take place properly.
Systemic blood pressure: systemic blood pressure is very important factor as it affects the Glomerular Filtration Rate (GFR). Low blood pressure or volume due to dehydration can result in decreased GFR.
Renal artery/arteriole diameters: The filtrate move through the renal artery and if it's diameter will increase or decrease it will affect the movement of filtrate. if diameter will decrease it can block the renal artery and can cause a huge damage.
Blood calcium level do not have any role in the kidney filterate formation or renal regulation.
Hence, the correct option is blood calcium level.
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.
