Answer:
Well, if all the herbivores disappeared, multiple things could occur. Without anyone keeping plants in check, plants may grow too abundant and may be harmful to the food web. Not only that, but predators that eat herbivors might starve without food. On the plus side, natural resources like water would increase without herbivores drinking/using it.
I hope this helps :)
Explanation:
The countercurrent heat exchanger that prevents arterial blood from overheating the testes is the pampiniform plexus of veins. The pampiniform plexus helps to regulate testicular temperature, allowing sperm maturation. It surrounds the testicular arteries and works as a countercurrent heat-exchanger system to cool the arterial blood before entering the testes. This is because the sperms can not develop if the testis is at body temperature.
Answer:
NO! They require a ton of attention, a large cage, and experience with birds. Parakeets are often marked as starter pets, but no, they are not.
First, they need a 3 feet long cage with 5+ toys that need to be changed each month. And they need natural perches, not the cheap wooden dowels, they will get feet problems. Most people don't do this, having a bored pet.
Second, parakeets will chew anything given/available to them, and a lot of things can be toxic to them, which can lead to the death of your pet.
Third, parakeets are messy and noisy. They poop a LOT and love to toss seeds around their cage. They also need millet and a calcium chew, which are also messy.
They also will want a friend, they are flock animals in the wild so 3-4 birds is a good number, but getting more birds means getting a large cage. The pet store will tell you it's fine, but it is not. ALWAYS SEEK HELP FROM A BIRD BREEDER.
Lastly, they need a bird proofed room to fly around in. No matter how large your cage is, they still need some out-of cage time.
Try a dove or pigeon instead, they are listen the #1 easiest and cheapest to care for pet bird.
4. DNA sequence comparison
5. Random mutations
Mammals. I am no scientist, but I think that they are closer to mammals due to the fact that they are warm-blooded, and they raise their young. Reptiles are cold blooded and usually leave their offspring to fend for themselves.