[pic]
|[pic] |1.3.5 Practice: DNA and Heredity |
| |Practice Assignment |
| | |
| |[pic] |
| |Biology Sem 2 (S2598061) |
| \
…show more content…
(1 point)
Prophase: the chromosomes darken and become more defined, the nucleic envelope breaks down
metaphase the Sister chromatids meet up in the MIDDLE. (m for middle and metaphase)
anaphase: the pairs move APART (a for apart and anaphase)
telophase: the new cells begin to develop
2. a) How does meiosis introduce genetic variation into offspring? Think about how the chromosomes line up.(1 point)
1 by crossing over in prophase I , 2 , by indpendenent assortment and three by mutations in S phase
b) How do the products of meiosis compare to the original cell? Think about chromosome number. (1 point)
Meiosis results in four daughter cells (gametes) which have half the number of chromosomes of the original cell. They are therefore called haploid cell
c) Why are there two sets of phases during meiosis, but only one during mitosis? Think about what is different about meiosis and mitosis. (1 point)
Mitosis is the cell cycle for somatic cells which are diploid (2n).
Meiosis is the cell cycle for germ cells (gametes) where they are haploid (n) so that is why they have two sets of phases.
3. a) A plant can have either tall (T) stems or short (t) stems. Two plants are crossed. One has the genotypeTt and the other has the genotype Tt. Fill in the Punnett square below for this cross. (1
2. At the end of meiosis, how many haploid cells have been formed from the original cell?
Recall from the background information that purple corn kernels are dominant and yellow kernels are recessive. The second ear of corn was the result of crossing two heterozygous ears of male purple corn (Pp x Pp). This is represented by the Punnett square below. Complete the Punnett square by writing the correct letters that correspond to each number indicated in the table. (4 points)
Apply your understanding of how alleles assort and combine during reproduction to evaluate a scenario involving a monohybrid cross.
Meiosis consists of one DNA replication and two nuclear divisions resulting in 4 daughter cells. The process which provides for genetic variation is crossing over. Crossing over occurs in the early stages when homologous chromosomes move together so that their chromatids form a tetrad. This is called synapsis and allows for the exchange of chromosome sections.
Which of the following is true about “meiosis”? Select all that apply. Answers: Reproductive cells undergo meiosis
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.
In meiosis the pairs of chromosomes (that code for possible outcomes of characteristics) temporarily join and exchange information (crossing over) creating different combinations of gene types (alleles). For example; a pair of chromosomes could be a dominant allele (gene type) and a recessive allele which might code for brown hair. After crossing over it might be recessive which could be blond hair.
The leptotene. This phase differs only slightly from the early stages of mitosis. Usually are the cells and nuclei of meiotic tissues bigger than that of their neighbouring tissues and often do they seem to be longer and are longitudinally structured. At regular intervals can thickenings be found, like beads on a string: the chromomeres. Their number, size and positioning is constant in each species.
Inside the human body, there are two different cells who help the reproductive system. Those are Mitosis and meiosis which are similar and different than one another.
16) If the S phase were eliminated from the cell cycle, the daughter cells would
Mitosis: Mitosis occur in five phases describing the changes through which the cells go through. These stages are prophase, prometaphase, metaphase, anaphase, and telophase. In prophase, the chromosomes condense inside the nucleus while centrioles move to the opposite within the nucleus sides in pairs. As this process
Cell division involves in events of cells dividing and replicating that results in two daughter cells or more. Mitosis is a type of cell division where chromosomes in the nucleus are divided into two identical sets of chromosomes in its individual nucleus. Nevertheless, meiosis is a type of cell division that decreases the cell’s chromosome numbers by half, and that is for the purpose of sexual reproduction. A typical human cell contains two sets of sex chromosomes, paternal and maternal,which give the diploid cell. which also gives ploidy number “2n”, and it is considered to be a diploid cell (two sets of chromosomes, 2n, complete set). Meiosis is
Compare and Contrast Mitosis and Meiosis Meiosis and mitosis describes the process by which cells divide, either by asexual or sexual reproduction to produce a new organism. Meiosis is a form of cell division that produces gametes in humans these are egg cells and sperms, each with reduced or halved number of chromosomes. The number of chromosomes is restored when two gametes fuse together to form a zygote. A cell with two copies of each chromosome is called diploid cell and a cell with one copy of each chromosome is called a haploid cell.
During this exam I was thinking about the steps of both mitosis and meiosis. When it came to the exam I thought I had that question, but it turns out I didn’t. The actual process of mitosis is prophase, metaphase, anaphase, telophase/cytokinesis, and lastly the two daughter cells. Along with the steps I also got the difference between the two. Going into the test I thought I had a good enough explanation for it, then I got to the questions and I got it wrong. I put D, which was mitosis produces haploid cells, but meiosis produces diploid cells. The correct answer was B, with is mitosis produces cells genetically identical to the plant cell, but meiosis does not. After reading both answers I understand the difference between the two.