Biology Quiz 6

Shark and Ray belong to cartilaginous fish. Cartilaginous fish (Chondrichthyes) is a fish of a class distinguished by having a skeleton of cartilage rather than bone, including the sharks, rays, and chimeras.

Hypothermia occurs in human beings. It occurs when the human body loses heat faster than it can produce heat, causing a dangerously low body temperature. Normal body temperature is around 98.6°F (37°C). Hypothermia occurs as temperature falls below 95°F (35°C).

In male sharks, two claspers are found attached to the Pelvic fin. The claspers are simply a modified portion of the pelvic fin, and since there are two pelvic fins, there are two claspers.

Adrenaline is a neurotransmitter in the sense that, within the brain, it helps neurons to communicate with one another.

The approximate time required for a heartbeat is 0.8 second. A normal resting heart rate for adults ranges from 60 to 100 (for children- 70 to 100) beats per minute. (Approximate time required for a heartbeat = 60 second ÷ average heart rate ≈ 0.8 second).

An artificial ecosystem is not self-sustaining, and the ecosystem would perish without human assistance. An aquarium is an artificial ecosystem. In aquarium, all the factors are regulated according to choice. These factors are type of species, food, sunlight and temperature, etc. Without humans, this ecosystem could not sustain itself.

Vitamin B₁₂, also known as cobalamin, is an essential vitamin necessary for healthy nerve tissue, brain function, and red blood cell production. Rich sources of vitamin B₁₂ are meat, fish, milk, cheese, eggs, etc.

Ketone bodies are chemicals that the body makes when there is not enough insulin in the blood and it must break down fat instead of the sugar glucose for energy. Testing for ketones in urine is important in people with diabetes.

The typical composition of exhaled air is about 18 percent O₂, 78 percent N₂, and 4 percent CO₂.

Warm-blooded animals are the animals which can maintain a body temperature higher than their environment. Mammals and birds are warm-blooded. Dolphins, whales, seals, sea lions, and otters are all mammals. Some examples of warm-blooded are whales, dogs, lions, cats, vultures, and raccoons. Reptiles, insects, and fish (amphibians) including snakes, lizards, turtles and crocodiles are cold-blooded.