Biology Quiz 8

Pregnant women usually become deficient in Calcium and Iron. During Pregnancy, the body needs iron to make hemoglobin — that's the substance in red blood cells that helps carry oxygen to organs and tissues. A developing baby needs calcium to build strong bones and teeth.

Vitamin K is a group of vitamins that the body needs for blood clotting. Blood clotting or coagulation prevents excessive bleeding internally and externally.

Men and women have an equal number of bones which is 206. A baby's body has about 300 bones at birth. These eventually fuse (grow together) to form the 206 bones that adults have.

A test-tube baby means fertilisation in vitro and then transplantation in the uterus. It involves fertilizing an egg outside the body, in a labouratory dish (vitro), and then implanting it in a woman's uterus.

There are 23 chromosomes in a human ovum and 23 chromosomes in human sperm. Healthy humans have 23 pairs of chromosomes in which 22 pairs are autosomes and 2 are sex chromosomes. The ovum (female gamete) is formed by the meiosis due to which they have only the half number of chromosomes, which means 22 autosomes (11 pairs) and 1 sex chromosome.

The nitrogen present in the atmosphere is utilised through microorganisms. Plants get the nitrogen from the soil, where it has already been fixed by microorganisms (bacteria and archaea). Bacteria and archaea in the soil and in the roots of some plants have the ability to convert nitrogen from the air (N₂) to ammonia (NH₃), thereby breaking the tough triple bond of molecular nitrogen.

Necrosis is cell or tissue death within a living body. It is a form of cell injury which results in the premature death of cells in living tissue by autolysis.

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

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.

Chlorophyll is an extremely important biomolecule, critical in photosynthesis, which allows plants to absorb energy from light. Chlorophyll absorbs light most strongly in the blue portion of the electromagnetic spectrum, followed by the red portion.