Genetics Exam 2

In most eukaryotes, the nuclear envelope that separates the DNA from the cytoplasm disassembles. The chromosomes align themselves in a line spanning the cell. As the cell elongates, corresponding sister chromosomes are pulled toward opposite ends.

1. List whether the student was positive or negative for each characteristic and include whether the characteristic is dominant or recessive. (6 points)

Genetic profiling is a contemporary issue relating to the individual and technology which restricts access to unbiased decisions and privacy. Genetic profiling interferes with the individuals bodily, genetic and behavioural privacy, as it can be used for the benefit of identifying bodies to using the results of a DNA test to choose whether to employ one individual over another, due to future concerns. It can easily be argued that genetic profiling is in the need of law reform as a result of legal implications and the lack of individual’s rights.

The final 2 property points were earned for the description and discussion of specific heat.

Define the term crossing over. (3 points) During meiosis’ prophase the homologous chromatids exchange segments.

B) A gene in a eukaryotic cell is transcribed and translated to produce a protein.

A) Meiosis consists of two cell divisions and is broken up into Meiosis I and Meiosis II. At the beginning of the Cell Cycle, in this case there are four chromatids each from the homologous pairs being A, a, B, b. This is the Diploid number (4) meaning it is 2 times the haploid number that will be seen at the end of meiosis II. During the S phase of interphase, the chromatids replicate and reach the end of G2 phase. Now starting meiosis, during the first stage of prophase I the chromosomes condense and pair up through synapsis with their sister chromatids creating AA, aa, BB, bb. After they pair up they go through a process called crossing over, where the homologous chromosomes share a piece of their genetic material with each other. Crossing over allows for the genetic diversity of chromosomes. Now there are four homologous chromosomes Aa, Aa, Bb, Bb, each containing heterozygous alleles because the sister chromatids exchanged genetic information with their homologous pair. During late prophase I, spindle fibers being to form where they will later attach to a homologous chromosomes centromere. The next stage is Metaphase I. During metaphase I, the homologous pairs line up at the metaphase plate, also known to be the center of the cell. The homologous pairs form a tetrad which is considered a group of four homologous chromosomes. These homologous chromosomes orient themselves randomly, which is know as the process of independent

2. In which phases of mitosis are sister chromatids visible, and attached to each other at the centromere?

B) Seasonal fluctuation of temperature is not a limiting factor in biome distribution if areas have the same annual temperature and precipitation means.

Test taking is one of the most nerve-racking things for most people. Most of the time tests can either make or break your grade, especially if it's worth majority of your grade. That fact that one piece of paper can show how much knowledge you have attained is very scary. In my experience of test-taking, I have found out that I get nervous about tests. The first AP Biology test of the year was no exception. To prepare for the test I studied for hours on end, when the day of the test finally came I went to the review session and took the test, and then the day after I was pleased with my results.

You are also provided with a heterozygous female, and a homozygous recessive male for a genetic cross. In this particular female, all the dominant alleles are on one chromosome, and the recessive counterparts are on the other homologous chromosome. Due to a chromosomal condition, in the female no recombination occurs between the M and N loci. Normal recombination occurs between the L and M loci. Diagram this cross, and show the genotypes and frequencies of all offspring expected from this cross.

Always use two letters to represent a genotype. There are two letters in a genotype because one gene comes from the mother and the other one comes from the father. The three possible genotypes are two capital letters(TT), one of each(Tt), and two lowercase letters(tt). Homozygous means two capital letters, or two lowercase letters. A homozygous genotype is (TT), or (tt). Homozygous, also means purebred. Heterozygous means one capital letter and one lowercase letter. A heterozygous genotype is (Tt). Heterozygous, also means hybrid. (TT)homozygous=purebred, (Tt)heterozygous=hybrid, (tt)homozygous=purebred. How it physically shows up is a phenotype. Examples of phenotypes are blue eyes, brown fur, striped fruit, yellow flowers. Controlled by two or more genes is polygenetic inheritance, it may be on the same or on different chromosomes. Three examples of this, are eye color, skin color, and blood group. They are located in corresponding positions on homologous chromosomes called loci. A dominant allele hides the effect of another allele. We represent this, with a capital letter. A recessive allele is hidden, unless it is placed with another

The discovery by Walter Flemming in the 1800s of thread like structures once visible only during cell division sparked the investigation into the contents and purpose of what was later coined as chromosomes. Although much of the specifics of the chromosomal components have been teased apart, many questions still remain about higher order chromosomal

Meiosis consists of two cycles, each containing different stages. During Prophase I in meiosis I, the free floating chromatin in the diploid cell will begin to condense and synapses occurs. Each chromosome within the cell contains two sister chromatids and during synapses, the homologous chromosomes will pair together to create a tetrad. In addition, the chromosomes will exhibit crossing over which also occurs during Prophase I. Crossing over describes the process in which any of the four chromatids exchange segments with each other to create more genetic diversity. During Prometaphase I, the nuclear envelope of the cell will begin to break down to prepare for later separation. The homologous chromosomes then move to

Chromosome – rod-shaped body in the nucleus of eukaryotes and prokaryotes that contains the hereditary units or genes seen particularly during cell division