<span>The structure of the feet and legs varies greatly among frog species, depending in part on whether they live primarily on the ground, in water, in trees or in burrows. Frogs must be able to move quickly through their environment to catch prey and escape predators, and numerous adaptations help them to do so. Most frogs are either proficient at jumping or are descended from ancestors that were, with much of the musculoskeletal morphology modified for this purpose. The tibia, fibula, and tarsals have been fused into a single, strong bone, as have the radius and ulna in the fore limbs (which must absorb the impact on landing). The metatarsals have become elongated to add to the leg length and allow the frog to push against the ground for a longer period on take-off. The illium has elongated and formed a mobile joint with the sacrum which, in specialist jumpers such as ranids and hylids, functions as an additional limb joint to further power the leaps. The tail vertebrae have fused into a urostyle which is retracted inside the pelvis. This enables the force to be transferred from the legs to the body during a leap </span>
<span>The muscular system has been similarly modified. The hind limbs of ancestral frogs presumably contained pairs of muscles which would act in opposition (one muscle to flex the knee, a different muscle to extend it), as is seen in most other limbed animals. However, in modern frogs, almost all muscles have been modified to contribute to the action of jumping, with only a few small muscles remaining to bring the limb back to the starting position and maintain posture. The muscles have also been greatly enlarged, with the main leg muscles accounting for over 17% of the total mass of the frog.</span>
The question is incomplete as it does not have the options which are:
A) n+1; n+1; n-1; n-1
B) n+1; n-1; n; n
C) n+1; n-1; n-1; n-1
D) n+1; n+1; n; n
Answer:
Option-1
Explanation:
The laws of inheritance were concluded from the result of Mendel's experiment which is based on the fact that gametes are formed. Later research suggested that gametes are formed by the process of meiosis which takes place in two phases and recombination is a characteristic of Meiosis.
If during anaphase I of meiosis I, the alleles fails to separate that is nondisjunction takes place at anaphase I, Then the resulting daughter cells will have unequal distribution of chromosomes.
One daughter cell will receive 1 extra copy of the chromosome while another daughter cell will receive 1 less chromosome therefore ploidy level will be n+1 and n-1.
During meiosis II, 2 more daughter cells will be formed with the same ploidy level therefore in last the meiosis will result in 2 (n+1) and 2 (n-1) cell.
Thus, Option-1 is the correct answer.
The answer is C, because if something contagious we’re to threaten the population of the species then not having any variant means they’re all the same and it would kill them all and cause them to go extinct
Answer:
DNA is found in the nucleus. So B.
Explanation:
DNA is found in chromosomes and chromosomes are found in the nucleus because the nucleus is basically the DNA of a cell.
2 is the answer hope this helps
