Answer: The correct option is D(Some produce toxic agents in the water).
Explanation:
Dinoflagellates are found in the phylum Dinoflagellata which are single celled organisms. They are mostly found in the ocean while few of them can live in streams, freshwater ponds and rivers. The following characteristics can be used to identify a Dinoflagellates, these include:
--> they are golden brown
--> they possess assimilative cell with indented waist.
--> they possess large nucleus with visible chromosomes.
It has been reported that many dinoflagellate species can produce various natural toxins. These toxins can be extremely toxic and many of them are effective at far lower dosages than conventional chemical agents. Therefore the option, Some produce toxic agents in the water, is a correct statement.
During aerobic respiration, complete oxidation of carbohydrates takes place. Glucose is broken down by oxygen to release energy, while carbon dioxide and water are the by-products of the reaction. The released energy is used to make a special energy molecule called Adenosine triphosphate (ATP).
Line of symmetry to split the circle into a half.
Scientists are working hard to find out more about cells, so they should know all of the cells. The Lokiarchaeota cell is one of the only ones they have yet to find out stuff about. Scientists also need to know about it because it is apart of our body and maybe sometimes they can cause infection in the body. Scientists need to know if it could lead to to some of the biggest infections ever.
in conclusion, the answer is because it can be the deadliest cell
The answer is C and the reason is because 1. Interphase:
The DNA in the cell is copied resulting in two identical full sets of chromosomes.
Outside of the nucleus? are two centrosomes, each containing a pair of centrioles, these structures are critical for the process of cell division?.
During interphase, microtubules extend from these centrosomes.
2. Prophase I:
The copied chromosomes condense into X-shaped structures that can be easily seen under a microscope.
Each chromosome is composed of two sister chromatids containing identical genetic information.
The chromosomes pair up so that both copies of chromosome 1 are together, both copies of chromosome 2 are together, and so on.
The pairs of chromosomes may then exchange bits of DNA in a process called recombination or crossing over.
At the end of Prophase I the membrane around the nucleus in the cell dissolves away, releasing the chromosomes.
The meiotic spindle, consisting of microtubules and other proteins, extends across the cell between the centrioles.
3. Metaphase I:
The chromosome pairs line up next to each other along the centre (equator) of the cell.
The centrioles are now at opposites poles of the cell with the meiotic spindles extending from them.
The meiotic spindle fibres attach to one chromosome of each pair.
4. Anaphase I:
The pair of chromosomes are then pulled apart by the meiotic spindle, which pulls one chromosome to one pole of the cell and the other chromosome to the opposite pole.
In meiosis I the sister chromatids stay together. This is different to what happens in mitosis and meiosis II.
5. Telophase I and cytokinesis:
The chromosomes complete their move to the opposite poles of the cell.
At each pole of the cell a full set of chromosomes gather together.
A membrane forms around each set of chromosomes to create two new nuclei.
The single cell then pinches in the middle to form two separate daughter cells each containing a full set of chromosomes within a nucleus. This process is known as cytokinesis.
Meiosis II
6. Prophase II:
Now there are two daughter cells, each with 23 chromosomes (23 pairs of chromatids).
In each of the two daughter cells the chromosomes condense again into visible X-shaped structures that can be easily seen under a microscope.
The membrane around the nucleus in each daughter cell dissolves away releasing the chromosomes.
The centrioles duplicate.
The meiotic spindle forms again.
7. Metaphase II:
In each of the two daughter cells the chromosomes (pair of sister chromatids) line up end-to-end along the equator of the cell.
The centrioles are now at opposites poles in each of the daughter cells.
Meiotic spindle fibres at each pole of the cell attach to each of the sister chromatids.
8. Anaphase II:
The sister chromatids are then pulled to opposite poles due to the action of the meiotic spindle.
The separated chromatids are now individual chromosomes.
9. Telophase II and cytokinesis:
The chromosomes complete their move to the opposite poles of the cell.
At each pole of the cell a full set of chromosomes gather together.
A membrane forms around each set of chromosomes to create two new cell nuclei.
This is the last phase of meiosis, however cell division is not complete without another round of cytokinesis.
Once cytokinesis is complete there are four granddaughter cells, each with half a set of chromosomes (haploid):
in males, these four cells are all sperm cells
in females, one of the cells is an egg cell while the other three are polar bodies (small cells that do not develop into eggs).
