Answer:
Nitrogen fixation
Explanation:
Certain soil bacteria, e.g., <em>Azobacter spp</em> can combine free nitrogen of the atmosphere with oxygen to form nitrates. This is called <u>nitrogen fixation</u>. Other nitrogen-fixing bacteria such as Rhizobium form symbiotic unions with the roots of leguminous plants called root nodules. They fix nitrogen to form nitrates which are used up by the host plant. Nitrifying soil bacteria, e.g., <em>Nitrobacter </em>convert nitrites to nitrates in a process called <u>nitrification</u>.
Answer:
Explanation:
Meiosis is a form of cell division that occurs in the sex cells of organisms. It ensures the reduction of a diploid cell to an haploid cell to allow for the formation of a diploid zygote after fertilization (contribution of both parents haploid sex cells to give a diploid zygote). Thus, this process is very essential and important.
The reduction is accomplished by 2 divisions after the duplication of chromosomes
- first division: separation of homologous pairs of chromosomes (this reduces the total in half)
- second division: separation of sister chromatids of a chromosome.
The rearrangement in meiosis occurs by crossing over/genetic recombination.
This is the exchange of genetic material between homologous pairs of chromosome bringing about a rearrangement and genetic variation
An example of a chromosomal abnormality that arises as a result of defects in this process is the Down Syndrome which is caused by a nondisjunction of the chromosomes 21 pair in a sex cell.
This condition produces offsprings that have some characteristic facial features, short stature etc
Answer:
This question is incomplete
Explanation:
Experimentally, when trying to determine the concentration of an unknown sample of CuSO₄ with known absorbance, a standard curve is used. The standard curve is a scattered plot/graph in which known concentrations and there respective/corresponding absorbance are plotted on a "X and Y axis" graph (scattered plot). The absorbance is represented on the y-axis while the concentration is represented on the x-axis.
Once this known values are plotted on the standard curve, an unknown value (either absorbance or concentration) can be extrapolated from the curve. What is missing from the question is data required for the standard curve.
This question shows the absorbance of the CuSO₄ has been determined (most likely using spectrophotometer), the concentration could have been extrapolated from a standard curve.
An example of a standard curve is provided in the attachment for guidance.
Water. the only 4 macromolecules are nucleic acid, carbohydrate, lipids, and protein
