Answer:
Antibiotic resistance can evolved in bacterial population in the following ways:
Explanation:
- In response to constant exposure to antibiotics some members of a bacterial population develop some beneficial mutations in some essential genes that gives them survival advantage in terms of food and space over the sensitive bacterial strains and hence they are capable of out-competing the sensitive bacteria.
- This happens due to the process of Natural Selection.
- These genes are called antibiotic resistance genes and bacteria usually carry them on plasmids in form of cassettes where genes resistant to multiple drugs are incorporated. These plasmids are called the MDR or Multi-Drug Resistance Plasmids.
- These resistant plasmids can be easily transferred among bacterial populations by conjugation, transformation or transduction or direct plasmid transfer.
- The resistant genes encode for proteins that render the drug ineffective by promoting their efflux from the cells, preventing their entry into the cell, chemically modifying them such that they become non-functional or altering the target site of the drug.
In meiosis one, homologous chromosomes only separate resulting in two cells. In meiosis II, the cells divide further, separating sister chromatids and resulting in four cells. So the cells are just even smaller with less chromosomes in each one.
Pros:
It is (mostly) based on pyrethrine spray which kills the
insects rapidly.
It not poisonous to other animals.
It uses synthetic, natural spray which is safe to use because
it breaks down within 10 minutes.
Te technique can reach tall forests.
It can be used in closed spaces ( greenhouses, basements
etc).
Cons:
It requires windless circumstances ( which is mostly at
nights).
Breathing fog may cause respiratory and throat irritation to
some.
Answer:
time? maybe I'm not to sure but I wanted to help
Answer:
1. The gametophyte generation is haploid.
2. The embryo is diploid.
3. The megaspore is haploid.
4. The sporophyte generation is diploid.
Explanation:
1. Gametophyte- The gametophytic generation is the structure which produces gametes in the plant. Since the gametes are haploid, therefore, the gametophyte us considered the haploid.
2. Embryo- The embryo is formed after the fusion of fertilization when zygote develops, therefore, is considered diploid.
3. Megaspore- the big size spore which is formed from by the meiotic division of the megasporocyte, therefore, is considered haploid.
4. Sporophyte- the sporophyte generation develops from the embryo which is diploid therefore is considered diploid.
