Biology Quiz 4

When the radius of blood vessels decreases, their capacity to hold blood is reduced, allowing more blood to return to the heart from which it is pumped into the arteries. As a result, blood pressure increases.

A photosynthetic vesicle found in bacteria is called a chromatophore. In some forms of photosynthetic bacteria, a chromatophore is a coloured, membrane-associated vesicle used to perform photosynthesis. Chromatophores contain bacteriochlorophyll pigments and carotenoids.

Cyanide poisoning causes death in seconds because it breaks the electron transport chain. Cyanide blocks the cellular electron transport mechanism and cellular respiration by inhibiting the mitochondrial ferricytochrome oxidase system and other enzymes.

Edward Jenner (1749 - 1823) was an English surgeon, who discovered a vaccination for smallpox. It is in fact, the world's first vaccine.

Edible part of cabbage is a vegetative bud. Vegetative buds are those from which stem leaves are grown.

Blood types are determined by the presence or absence of certain antigens. There are 4 main blood groups – A, B, AB and O. Blood group is determined by the genes inherited from the parents. AB-positive blood type is known as the “universal recipient” because AB-positive patients can receive red blood cells from all blood types.

The huge muscles that power the wings attach to a flat part of the breastbone called the keel. Some flightless birds, including ostriches, do not have a keel.

Sleeping sickness is caused by microscopic parasites of the species Trypanosoma Brucei. It is transmitted by the tsetse fly (Glossina species).

Myopia, also known as shortsightedness or nearsightedness, is a very common vision disorder. It is the inability to see distant objects clearly unless they are relatively close to your eyes. This causes light to focus in front of the retina instead of directly on it.

Dengue viruses (DENV) are the causative organism of dengue fever. They are transmitted to humans through the bite of an infected Aedes species mosquito.