Answer:
Reproduction?
↪️ As evolution progressed, cells of successively higher levels of complexity must have arisen, and it was absolutely essential that they had the ability to make likenesses of themselves
Levels of Reproduction:
- Molecular replication
- In 1953 it was established that DNA molecules consist of two complementary strands, each of which can make copies of the other
- There are four bases in DNA: thymine, cytosine, adenine, and guanine. In the middle of each rung a base from one strand of DNA is linked by a hydrogen bond to a base of the other strand
2.Molecular reproduction
- a substance that is so similar structurally to DNA that it is also formed by template replication of DNA.
- Proteins are reproduced directly; however, such other substances as carbohydrates, fats, and other organic molecules found in cells are produced by a series of enzyme-controlled chemical reactions, each enzyme being derived originally from DNA through messenger RNA
3.Cell repruduction
- The chemical constituents of cytoplasm (that part of the cell outside the nucleus) are not resynthesized from DNA every time a cell divides
4.Binary fishion
- the most common mode is binary fission, the division of a cell into two separate and similar parts.
- In bacteria (prokaryotes) the chromosome (the body that contains the DNA and associated proteins) replicates and then divides in two, after which a cell wall forms across the elongated parent cell.
5.Multiple fission
- Many algae (e.g., the Siphonales and related groups) are multinucleate.
- In the Myxomycetes, the fusion of two haploid gametes or the fusion of two or more diploid zygotes (the structures that result from the union of two sex cells) results in the formation of a plasmodium—a motile, multinucleate mass of cytoplasm.
- Some algae, some protozoans, and the true slime molds (Myxomycetes) regularly divide by multiple fission.
Reproduction of organisms
- In single-celled organisms (e.g., bacteria, protozoans, many algae, and some fungi), organismic and cell reproduction are synonymous, for the cell is the whole organism.
- The parent cells separate and subsequently reproduce by binary fission. Sexuality is present even in primitive bacteria, in which parts of the chromosome of one cell can be transferred to another during mating.
Explanation:
#CARRYONLEARNING
