Meiosis

Questions
When two gametes unite, they form a diploid zygote
Examples of gametes are sperm and ovum
There are two copies of each chromosome in germline cells
There are two copies of each chromosome in gamete cells
In prophase I, homologous chromosomal pair crosses over to form a pair and exchanges DNA forming recombinant chromosomes
Crossing over is the activity in which homologous pairs of chromosomes exchange equal parts. The latter mixes the alleles on the parent’s chromosomes ensuring that the offspring are not identical to the parent.
Metaphase I is the arrangement of the homologous chromosomes at the poles equidistant from the centroid in readiness for meiosis.
In anaphase I, the bivalent chromosomes separate and move to the opposite poles by the action of the spindle
In the telophase I, the separated chromosomes reach the poles and nucleus starts to form around them. This leads to the formation of a cell in a process referred to as cytokinesis.
Telophase II marks the onset of meiosis II. The nuclear-encasing bursts and the spindle apparatus form
In metaphase II, the daughter cells produced in meiosis I am pulled to the opposite poles by the spindle.
In the anaphase II, the chromatids of the sister cell separate and move towards opposite poles.
In the telophase II, a nucleus forms around the set of chromosomes to produce a haploid cell
A haploid cell is a cell that contains only a single type of each chromosome.
Potato lab report
Method
Freshly sliced potato chips, ruler, water, and salt were used.

Three water samples with varying salt concentration were used. The first sample was more dilute than salt concentration in the potato chip (hypotonic solution). The second contained the same salt concentration as the potato chip (isotonic solution). The third contained a higher salt concentration than the potato chip (hypertonic solution). The chips were measured to be of equal length and the immersed in the solutions for the same length of time after which their lengths were measured again.
Data and interpretation
The chips in the hypotonic solution increased in size as the water moved into the chip through osmosis. The chips in similar concentration as the solution were found to have remained the same. This is because there was no concentration gradient hence osmosis could not take place. The chips in the hypertonic solution decreased in size as water molecules moved out into the more concentrated solution through osmosis (Davidson, 1934).
Evaluation
From the experiment results, its evident that osmosis is dependent on concentration gradient. It is also evident that water molecules move from zone of high concentration to that of low concentration across a semipermeable mambrane.
The experiment was a success and can be improved further by using young aged totatoes as they are more permeable compared aged tomatoes.
References
Davidson, A. (1934). A simple presentation of the concepts of osmosis, osmotic pressure, and osmotic work. Journal of Chemical Education, 11(9), 499. doi: 10.1021/ed011p499