The sister chromatids are then pulled apart by the mitotic spindle which pulls one chromatid to one pole and the other chromatid to the opposite pole.
The chromosomes line up neatly end-to-end along the centre (equator) of the cell.
The centrioles are now at opposite poles of the cell with the mitotic spindle fibres extending from them.
The mitotic spindle fibres attach to each of the sister chromatids.
The DNA in the cell is copied in preparation for cell division, this results 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.
Answer:
A person can have normal chromosomes in number and structure, but still have a disease or condition caused by a mutation in one or more of the genes on the chromosomes. A single gene defect usually does not cause the chromosome structure or number to be abnormal.
Explanation:
I'm not sure if this is correct but hope it helps.
<h3><u>Answer;</u></h3>
It combines with water to form glucose.
<h3><u>Explanation;</u></h3>
- Photosynthesis is a process by which green plants make their own food by using solar energy from the sun, together with water and carbon dioxide.
- Carbon dioxide, water and light are all needed for photosynthesis to take place. During the process solar energy from the sun is used to convert carbon dioxide and water into the simple sugar glucose.
- <em><u>Substance A is the above question represent carbon dioxide which combines with water in presence of light to form simple sugars and oxygen gas.</u></em>
- The equation for the reaction is;
6CO2 + 6H2O + light energy = C6H12O6 + 6O2.
Answer:
Plant cells deal with osmosis by being enclosed in a cell wall.
Animal cells use active transport systems to deal with the problem of osmosis.
Fresh water protists have contractile vacuoles to deal with osmosis.
Many bacteria have cell wall to protect them from osmosis.
Explanation:
Plant cells have a rigid cell wall. If a plant cell is places in a place where the conditions are hypotonic, then the cell will tale up water by osmosis but the cell wall will prevent it from bursting. This condition is termed as the cell being 'turgid'.
As animal cells do not have the rigid cell wall, they use the mechanism of active transport system to stop the cell from bursting during osmosis. In this process, ions are moved out of the cell so that the pressure in the cell due to osmosis can be reduced.
Fresh water protists have a structure present in them called as the contractile vacuole. The contractile vacuole has the capability to remove any excess water from the cell as well storing water if there is not enough water.
Bacteria have peptidoglycan cell walls to prevent osmosis.
Answer:
<u>Sister chromatids are identical forms of chromatids of a chromosomes. They are mostly formed by semi-conservative replication of DNA molecule of a single chromosome.Thus they are like </u><u>'photocopies' </u><u> of original parent chromosomes; joined together at the Centromere</u>.
They are exactly similar in all ramification; with the same gene and allele compositions..
<u>However; slight differences arise between the two identical sisters due to </u><u>mutation</u><u> from</u><u> errors </u><u>at replication;and also in the length of telomere repeats.</u>
Non-sister chromatids are dissimilar forms of chromatids of a chromosomes formed when each half of a chromosome at fertilisation from separate haploid sex-cells, of each parent. fused.They contain different genetic composition;because they are not on the same homologous chromosomes.Therefore crossing -over ensure variation.
<u>However, they are genetically similar in composition; if they are contained in homologous chromosomes</u>. This is because Synapsis of bivalent of these chromosomes allow genetic material to be shared by chromosomal crossing-over between the non-sister chromatids on the chromosomes ; therefore identical genetic characteristics are shared .
Explanation:
