Answer:
Option (C)
Explanation:
The Permian period refers to the last period of the Paleozoic era, which started about 300 million years back and ended by about 250 million years back. The Permian period was ended by the occurrence of a catastrophic mass extinction event, commonly known as the Permian-Triassic (P-T) boundary.
Soon after this eruption, there occurred rapid evolution of plants and animal species, and this was possible because of the following reasons-
- Adaptive radiation- This type of evolutionary process refers to the condition when numerous species are created from one single ancestor. It takes place when there occur sudden changes in the environmental conditions, favorable for their growth and expansion of organisms.
- Ecological opportunity- It is directly associated with the adaptive radiation type of evolutionary process. When changes in the environmental condition occur, it allows the organisms to adjust to the new environment and eventually gets multiplied.
- Lack of competition- By the end of Permian, about 75% of all the living species on earth were wiped out. So, the new species that appeared had no competition and so they were able to grow in large numbers over a specific period of time.
Thus, the correct answer is option (C)- three of the above.
Answer:
The weakest part of a long developing and adolescent bone is called growth cartilage (epiphyseal plate)
Explanation:
Both children's bones and adults' bones are at risk of injury. However, in the case of bones in a child, they are subject to an injury known as a growth cartilage fracture or epiphyseal plate. These growth cartilages are areas that are in full development in the vicinity of long bones. Its function is to help establish the length and shape of the bone in the process of maturation. The growth of a long bone happens from the end next to the growth cartilage. In adulthood, these growth cartilages are strengthened forming the bone.
Answer:
a. They are complex structures attached to the centromeres of chromosomes that bind to spindle microtubules.
d. They are enzymes that control progression through the cell cycle.
Explanation:
In the eukaryotes during cell division, the spindle apparatus gets attached to the chromatid in a structure called kinetochore. It is present in the centromere. It supervises, control and starts the striking movement of chromosome during division. For chromosome editing its protein helps in holding the sister chromatid. Every chromatid have there own kinetochore that faces in the opposite direction, and are also attached to the opposite pole of the mitotic spindle apparatus
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(sponge) now adding a bunch of words to make this longer.
