Explanation:
During the process of prophase I, the nuclear envelope containing chromosomes has only partly broken down homologous chromosomes are joined together by proteins and a complex or pairing call synapsis- corresponding genes on sister chromatids are aligned precisely.
The syanapsis allows for crossing over which is the exchange of segments of chromosome, between non-sister homologous or similar chromatids crossing over happens at chiasmata, the point where non-sister chromosomes are joined.
Further Explanation:
All the genetic information within the eukaryotic cell is stored within the nucleus as helical DNA. This DNA is tightly wound around histones as chromosomes. In meiosis, the number of chromosomes (2n) is halved to 23 chromosomes (haploid number)through meiotic divisions, producing 4 haploid (n) germ cells or gametes (sperm or eggs), each containing half the number of chromosomes as its parent cell.
In Meiosis I
- homologs pair off into bivalents
- At crossing over: the exchange of segments of chromosome, between non-sister homologous or similar chromatids crossing over happens at chiasmata, the point where non-sister chromosomes are joined in prophase I forming bivalents; tetrads are formed.
- Spindle fibers from centrioles join sister chromatids together at their centromeres in metaphase I, pulling them to the equator of the cell;
- then, in anaphase I, while joined, they are pulled to opposite sides of the cell; the cell body splits and the nuclear envelope reforms in telophase I
In Meiosis II...
- Later, in prophase II, the nuclear envelope disintegrates and mitotic spindle fibers are formed
- independent assortment occurs. in metaphase II of meiosis: spindle fibers attach to centromeres, chromatids align independently at the equator. Genes segregate independently into new combinations as sister chromatids are pulled apart by their centromeres in anaphase II
- in telophase II the cells' nuclei and membrane are then formed with each containing the haploid number (n)
- Following the formation of gametes in the last stage, randomized fertilization occurs in sexual reproduction sperm cells fertilize an ovum to form a zygote. This occurs randomly by chance, to result in a complete set of chromosomes 2n, that is a novel combination of half each parent's number of chromosomes
Learn more about mitosis at brainly.com/question/4303192
Learn more about transcription at brainly.com/question/11339456
Learn more about DNA and RNA at brainly.com/question/2416343?source=aid8411316
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Answer:
b
Explanation:
I looking at the electro magnetic spectrum I can tell scientists if things are moving toward the Earth or away from the Earth
Answer:
Rough endoplasmic reticulum differ from smooth endoplasmic reticulum by the presence and absence of ribosomes in their surface.
Explanation:
Rough endoplasmic is named so because RER contain ribosomes at their surface and due to the presence of ribosomes rough endoplasmic reticulum play an importnt role in protein synthesis or translation.
Whereas smooth endoplasmic reticulum does not contain any ribosome in its surface.smooth endoplasmic reticulum helps in the biosynthesis of lipid and steroids along with detoxification of toxic compounds.
I think the answer here is neurons, the nerve cells
Answer:
All are true of the movement of Earth's atmosphere except :
d. Warm air is less dense than cool air so it tends to sink towards the Earth's Surface.
Explanation:
- When gases heat up, their volume increases and density decrease.
- A decrease in density causes a substance to become lighter.
- Thus, when air warms up due to heat from the sun its density decreases and it gets lighter.
- So, it will move up.
- The Cooler air in turn is denser and heavier so it will sink towards the Earth's surface.
- Hence, the statement d , which states that 'warm air is less dense than cool air so in tends to sink towards the Earth's Surface' is FALSE.