A mutation is a change in a DNA sequence. Mutations can result from DNA copying mistakes made during cell division, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses. Germ line mutations occur in the eggs and sperm and can be passed on to offspring, while somatic mutations occur in body cells and are not passed on.
Recessive mutations inactivate the affected gene and lead to a loss of function. For instance, recessive mutations may remove part of or all the gene from the chromosome, disrupt expression of the gene, or alter the structure of the encoded protein, thereby altering its function.
Answer:
An example of a pathological condition that affects the skeleton is Osteoporosis
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Explanation:
Osteoporosis is a disease that affects the skeleton in which the quality and density of bone are reduced. In this condition, the chances are high for easy bone fracture as they become fragile. Bone density takes place in very silently but progressively.
Osteoporosis condition leads to higher bone loss (osteoblast) than the growth of new bone (osteoclast). Bones become like a honeycomb, fragile and easy to fracture. This pathological condition generally occurs due to the imbalance of hormones that are a parathyroid hormone, estrogen, and to a lesser extent of testosterone.
This condition can be prevented by proper diet and appropriate amount of protein and vitamin D.
Answer:
selective pressures will decrease the number of birds with large beaks.
Explanation:
Answer: Option D) Cells in multicellular organisms are specialized to perform certain functions.
Explanation:
Multicellular organisms include humans, reptiles, birds etc. While unicellular organisms include amoeba, paramecium etc
From the examples given, the cells of multicellular organisms are specialized in function in that:
- cells that perform similar functions are put together as tissues, organs or system e.g digestive system consists of the similar cells that help to break down food into pieces
On the other hand, unicellular organisms possess just one cell that do all the functions.
Thus, the difference between both is that cells in multicellular organisms are specialized to perform certain functions.
Answer:
The kidneys maintain homeostasis by controlling the amount of water, ions, and other substances in the blood. They also secrete hormones that have other homeostatic functions.
Explanation:
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