energy enters an ecosystem through photosynthesis. By feeding on plants and on one another, animals play an important role in the movement of the matter/energy though. they also influence the quantity of plant and biomass present. so the anwser is D, secondary consumers to tertiary consumers
Answer:
90,000 i think if its right your welcome if its not let me know
It took BP 87 days to stop the flow of oil they monitor it for 48 hours to make sure it was going to hold
Answer: The DNA on the paternal copy of the chromosome will be methylated at the imprinting center, while the DNA on the maternal copy of the chromosome will not be methylated in this region.
Explanation:
Chromosomes are DNA structures associated with proteins such as histones. They are found in the nucleus of cells and contain genetic information for the development and functioning of an organism. Human beings are diploid, meaning that they possess two copies of each of the 23 chromosomes (a total of 46).
Gametes, which are sex cells such as the sperm (produced by the male) and the egg (produced by the female) that are haploid. This means that they possess only one chromosome of each pair. During fertilization, a male gamete fuses with a female gamete to generate a zygote, which will give rise to a new human being. <u>This new individual will possess half of the genetic material from its father and half from its mother. Thus having a total of 46 chromosomes, 23 from each parent</u>.
Genetic imprinting modulates gene expression by chemical modification of DNA and/or modification of chromatin structure. Often, genetic imprinting causes a gene to be expressed only on the chromosome inherited from one of the parents. One example of imprinting is DNA methylation, which is a process by which methyl groups are added to DNA. <u>Methylation modifies DNA function when found in the promoter gene, repressing gene transcription. This means that a methylated gene will not be expressed</u>, that is, it will not produce a protein encoded by that gene. So, if a region of DNA is imprinted in the sperm cell, the paternal chromosome inherited from this sperm will be methylated in the genes of the offspring. And the offspring will only express the maternal copy inherited, which will not be methylated.
Answer:
- Diploid → Prophase, metaphase, and anaphase
- Haploid → Telophase
Explanation:
During prophase I, chromosomes get condensed. Each of the chromosomes gets in pair with its homologous one. They do so to make the crossing-over possible, a stage where they interchange their parts → 2n
During metaphase I, each of the homologous pairs is driven to the equatorial plane, where they randomly line up → 2n
During anaphase I, occurs the independent separation of homologous chromosomes that migrate to opposite poles of the cell. This separation generates different chromosomal combinations in the daughter cells. There are two alternatives per homologous pair → 2n
In telophase I, half of the chromosomes are already in one of the poles, while the other half is on the other pole. Each group of chromosomes has now half the number of the original cell. The nuclear membrane forms again in each pole → n
Finally, occurs cytokinesis, which involves the invagination of the cell membrane and cytoplasmic division.
The two new cells are ready for meiosis II.
