1.1
Meiosis I
The first meiotic division: diploid → haploid
Prophase I: Chromosomes condense, nuclear membrane dissolves, homologous chromosomes join and occurs crossing over.
Metaphase-I: the homologous chromosomes align in the middle of the cell. Spindle fibers from the centrosomes connect to the chromosomes.
Anaphase -I: Spindle fibers contract and split the homologous chromosomes, moving them to opposite poles of the cell.
Telophase -I: Chromosomes decondense; cell divides to form two haploid cells.
1.2 Meiosis II
The second division: separates sister chromatids (these chromatids may not be identical due to crossing over in prophase I)
Prophase II: Chromosomes condense, nuclear membrane dissolves, centrosomes move to opposite poles (perpendicular to before)
Metaphase-II: the chromosomes align in the middle of the cell. Spindle fibers from the centrosomes connect to the chromosomes (at the centromere)
Anaphase-II: Spindle fibers contract and split the sister chromatids, and moves them to opposite poles of the cell.
Telophase-II: Chromosomes decondense,cells divides again to form another 2 haploid daughter cells. Final: 4 new cells.
2. The differences:
Mitosis:
- has 1 division per cycle
- one cell produces 2 new cells
- the genetic information in the mother-cell and the daughter-cells are the same. ( the number of chromosomes is also the same)
- it occurs in somatic cells
Meiosis:
- two divisions per cycle
- one cell when divides produces 4 new cells
- the new cells have different genetic information. mixes the genetic material from the parent cells
- the number of chromosomes of the daughter cells is half of the mother's.
3. Prokaryotic organisms don't divide through mitosis, they use a different process called binary fission. Only eukaryotic organisms, or those whose cells have a defined nuclei, undergo mitosis. Bacteria, for example, are prokaryotic organisms that use binary fission.
4.
It can't occur. Cross over is the exchange of DNA between homologous chromosomes. That will result in recombinant chromosomes during sexual reproduction. It can't occur on different chromosomes because they don't code for the same genes.
5. There are a lot of different theories about that, but it's mostly believed that meiosis must evolve before sexual reproduction. That's because The cell replicates their information first and then divides. Plus the cell does that even though it didn't recombine DNA with another organism (sexual reproduction).
Answer:
Endometrosis could negatively affect the probability of gestating an embryo if they are growing inward. The affection of the fallopian tubes and the uterus could alter the implantation or even generate complications for the embryo during pregnancy.
In addition, endometriosis generates painful conditions in the abdominal area to the point that it is considered as menstrual cramps during menstruation, women who suffer from this disease suffer a lot during the menstrual cycle.
Regarding the reproductive system, those female reproductive systems that suffer from this disease are considered potentially malignant, since many malignant neoplasms are incited to appear in these foci of excessive proliferation of the endometrium.
Explanation:
Endometriosis can affect the walls of the fallopian tube and the uterus, since it occurs in the endometrium, that is why it bears that name.
The macroscopic appearance of this lesion at the histological level is a tumor nodule, since they are proliferative foci.
The normal, or emmetropic, eye accommodates properly.
Students are investigating the distribution of dandelions using quadrats. The students could during their investigation is they can do the pH test and the effect if it is happening or not.
<h3>What is pH?</h3>
pH is the measurement of the acidity or alkalinity of a substance. PH is a scale that marks from 0 to 12. The substance above 7 is acidic and the substance that is basic comes after 7. 7 is the number for neutral, which is pure water. The pH test is very easy to conduct.
To be sure that pH of the soil will not affect the distribution of dandelions. They first test the pH of the soil.
To learn more about pH, refer to the link:
brainly.com/question/1979364
#SPJ1
They could discover which organisms are closely related to the mammoth, and which one is the most closely related.
