Answer:
Each one is fromt the plant cell
Explanation:
Answer:
- One spermatogonium produces 4 spermatids FALSE. One primary spermatocyte produces 4 spermatids.
Explanation:
Germ cells are diploid reproductive cells in charge of gamete production. Germ cells divide by mitosis and meiosis. Through mitosis, they originate more sexual cells, but through meiosis, they produce gametes -sperm and egg cells-. This process is known as gametogenesis.
Gametes´destiny is to merge during fecundation, and a new diploid cell called zygote emerges through fertilization. The zygote is a complete cell and suffers successive mitosis to form the new organism.
Spermatogenesis is the process of production and maturation of sperm cells. Spermatogonia are the masculine diploid germ cells, carrying 46 chromosomes. These germ cells suffer mitosis to reproduce. Some of them stay as spermatogonia, and some others become primary spermatocytes, which are in charge of gamete production. Primary spermatocytes are also diploid cells, meaning that they still carry 46 chromosomes.
Each primary spermatocyte replicates its genetic material and then goes through meiosis I to produce two daughter haploid cells called secondary spermatocytes, each of them carrying 23 chromosomes. Each secondary spermatocyte will produce two other haploid daughter cells by meiosis II.
The total result from the two cellular divisions of each primary spermatocyte is four haploid daughter cells called spermatids.
During spermiogenesis, spermatids mature into spermatozoa or sperm cells. Each sperm cell characterizes by being composed of a head, midpiece, and tail.
- DNA replicates once, but cells divide twice TRUE
- The products are spermatozoa that each have a head, midpiece, and tail TRUE
- Spermatids containing 23 chromosomes (1n) are produced TRUE
- One spermatogonium produces 4 spermatids FALSE. One primary spermatocyte produces 4 spermatids.
- Genetically diverse spermatids are created TRUE
The factors are: The size of the sample, the extraction method, the method of purification and preservation of the DNA.
The quantity and quality of DNA can be greatly improved by performing PCR.
* Purification of nucleic acids is a key step for functional studies in biology. Because of the great diversity of living organisms in nature, purification becomes a real challenge for researchers, especially cell lysis.
The evolution of lysis methods has made it possible to improve efficiency, speed and simplicity. But, this lysis step remains a crucial step for the efficiency and the quality of the purification.
Answer:
C)All of the choices are correct.
Explanation:
The major blood types include; A, B,AB and O. Type A has A antigens, B has B antigens AB has both A and B antigens and O has neither.
A person's immune system produces antibodies against any antigens not found in his blood.
Before giving a blood transfusion, it is necessary to determine the blood type of the recipient and that of the donor so that blood can be appropriately matched. This is called blood typing. This helps prevent ABO incompatibility which might lead to several fatal symptoms and reactions. These include;
Fever and chills
Abdominal, back and chest pains
Jaundice
Nausea
Muscle pains
Systemic shock and organ failure.