Question

1.Simple, prokaryotic organisms have been on Earth for over 3 billion years and have been able to grow and evolve into many different and successful prokaryotic organisms. Which structure evolved in cells approximately one billion years ago that allowed for the forming of more complex, multicellular organisms?
A) nucleus
B) ribosome
C) plasma membrane
D) golgi apparatus

2.
Genetically modified grass varieties that carry genes for disease and drought resistance are now available. They were produced by recombinant DNA technology. However, the government has still not approved the sale of most of them, due to cautionary factors. What is the main reason for this concern?
A) The possibility of the fragile recombinant organisms dying.
B) The possible patent violations from competing biotechnology companies.
C) Because the new genetically altered grasses are too expensive for consumers.
D) Release of genetically engineered organisms into the environme


3. At the end of meiosis II, how does the DNA in each of the four new cells compare to the DNA from the original cell?
A) half as much and genetically the same as the original
B) twice as much and genetically the same as the original
C) half as much and genetically different from the original
D) twice as much and genetically different from the original


4.At the end of meiosis II, how does the DNA in each of the four new cells compare to the DNA from the original cell?
A) half as much and genetically the same as the original
B) twice as much and genetically the same as the original
C) half as much and genetically different from the original
Eliminate
D) twice as much and genetically different from the original

5.Speciation has definitely occurred when two groups of related organisms
A) cannot interbreed successfully.
B) have drastically different behaviors.
C) have drastically different appearances.

D) become permanently isolated from each other.

Answer 1

1. I believe the answer is the nucleus. Nucleus is a part of cell in living organisms that stores genetic materials. It is believed that the eukaryotic nucleus could have evolved from the fusion of thermoacidophil archebacterium fused with a motile eubacterium. This is a defining feature of eukaryotic cells. There is evidence that nuclear pore complexes and nuclear membranes co-evolved with the endomembrane system, and the last eukaryotic common ancestor had fully functional nuclear pore complexes.

2. Recombinant DNA technology involves altering genetic material outside an organism to obtain enhanced and desired characteristics in living organisms or as their products. It involves insertion of DNA fragments from a variety of sources, having desirable gene sequence via appropriate vector. However, the government has still not approved the technology in genetically modified grass because of the concern of the release of genetically engineered organisms into the environment and the concerns about environment safety.

3. Meiosis is the process of cell division which takes place in the gametes cells where the a diploid (2n) parent cells divides into four haploid cells. The process takes place in two stages namely meiosis I and meiosis II. At the end of meiosis II the daughter cells formed are haploid (n) meaning they have one set of chromosomes as compared with the parent cell. This means the four daughter cells have half as much and genetically the same as the original parent cell.

4. Speciation is the process by which new species are formed from a population. This process takes place as a result of geographic, anatomical, physiological or behavioral factors that prevent previously interbreeding populations from breeding with each other. Thus, in this case, i would say that speciation has definitely occurred when two groups of related organisms become permanently isolated from each other.