Answer:
The correct answer is -
1. right-handed
2. right-handed
3. positive
4. left-handed
5. negative
6. negative
Explanation:
In a circular bacterial chromosome, the structure of DNA is a right-handed double helix In a circular bacterial chromosome.
If DNA is twisted in the right-handed direction, it becomes overwound. Overwinding results in positive supercoiling takes place. If DNA is twisted in the left handd direction, it becomes underwound. Underwinding results in negative supercoiling.
f. One effect negative supercoiling in bacterial chromosomes is to promote separation of the two strands of DNA in the double helix
Answer: the antibodies mistakenly identify the cells as foreign material
Explanation:
Q1:
Answer:
Studies have reported that due to predation of pythons on rabbits, the population of other predators is badly affected.
Bobcats are a natural predator of rabbits thus they come in a competition with pythons for food. As pythons are more powerful so they target rabbits more easily than Bobcats. The population of Bobcats has been declined by 90% or more due to the establishment of pythons in the Everglades.
<em>Alligator mississippiensis </em>or American alligators are also abundant in Everglades and just like Bobcats they compete with pythons for their food. They can even kill pythons if pythons are smaller in size than them, but python will kill alligator if he is of smaller size. Although rabbits are food for both alligator and Python but Alligator is a key stone specie and it has very important ecological role, because it digs holes in land that retain water upon rainfall. These water hole provide water in the extreme dry weather and help in survival of other small specie like insects and birds.
So, we can expect the population of Alligator, Bob cats and other small insects and birds to decline rapidly if Python population kept on increasing with same speed.
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Q2:
Answer:
There is no doubt that Pythons pose serious threat for both humans as well as survival of other organisms like Alligators and birds. However, I donot think that “Python challenge” is a reasonable way to kill or remove Pythons. Because It can threat the lives of many individuals who take part in competition, although they are trained but still they are nor professionals and get training of only few weeks so it is not safe competition.
There should be some strategy of introducing natural predators like Brown beers, Cougars and Alligators which can kill python naturally without staking the life of humans at risk.
Hope it helps!
After phosphates and nitrates enter a water system, the steps of eutrophication include the rapid growth of algae, death of underwater plant species, depletion of oxygen in the water, and the death of fishes and invertebrates. The correct option would be B.
Eutrophication refers to the excessive enrichment of water bodies by nutrients such as phosphates and nitrates thereby facilitating the rapid growth of some aquatic species with negative effects.
Once a water body becomes excessively enriched with phosphates and nitrates, the following is a sequence of events that follows:
- Algal bloom: the nutrients facilitate the rapid growth of algae
- The bloom of algal species results in the death of underwater plants as a result of inadequate light.
- The death of the underwater plants and the accompanying microbial activities in decomposing them cause oxygen levels in the water to drop.
- Reduction in oxygen level causes fishes and other water invertebrates to die due to hypoxia
Therefore, the correct steps of eutrophication according to the illustration is IV, II, I, and III.
More on eutrophication can be found here: brainly.com/question/13232104
The correct answer is optionD 134/200.
The frequency of the dominant allele can be calculated by the summation of the frequency of the homozygous individual frequency that has dominant allele and half of the heterozygous individuals, as half of the heterozygotes have dominant allele.
The frequency is no of individual of desired trait divided by total number of individual.
The calculation is shown below:
