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Showing posts from May, 2021

Organ regeneration/regrowth

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  Living things are magical when it comes to the ability to repair and regrow. We need this ability to maintain the healthy functioning of our bodies so as to increase the chance of survival. Some animals have better regeneration ability than human, here is a video to show how salamander regenerates its limb: The salamander is known for its regeneration capacity. They can regrow the limb, heart, tail, brain, eye tissues, kidney and spinal cord. To understand how they do it, let's look at what stem cells are. Stem cells Our body is made up of different types of cell. Most cells have a specific function, such as red blood cells, nerve cells, and heart cells. Stem cells provide new cells for the body and replace lost or damaged cells. They can divide into new stem cells or specialised cells that made up other body parts. Image credit: Genome Research Limited There are 3 types of stem cell:  embryonic ,  adult , and  induced pluripotent  stem cells.  Embryonic ...

Basics of blood type

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  8% of our body weight is made of blood. It carries oxygen, nutrients, hormones and other substances around our body to keep us alive. We learnt from school that there are four blood type categories: A, B, AB and O. But what are the differences between these blood types and why can't we just donate blood to another person with a different blood type? Antigens and antibodies Blood type is identified by different antigens and antibodies contained in the blood. Antigens are protein molecules on the surface of red blood cells (RBC). Antibodies are proteins in plasma. They form a defence system in our body, which detect foreign substances like germs and alert the immune system to destroy them. The ABO blood types Type A : Contains type A antigen on RBC and anti-B antibody in plasma. Type B : Contains type B antigen on RBC and anti-A antibody in plasma. Type AB : Contains both type A & B antigens on RBC but no antibodies in plasma. Type O : Has no type A nor B antigen on RBC but bot...

Is eating eggs bad for the environment?

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 This question came into a discussion with my colleagues tonight when talked about having a vegan diet. Being a vegan can be something to do with religion, concern with animal welfare, health, and for the sake of the environment. To answer the question, let's look at how do chickens lay eggs.  Illustration: The Spruce / Ashley Nicole Deleon The lifespan of a chicken is 5-10 years, and hens start laying eggs around six months old. Eggs are formed from the inside to the outside. Each hen has a thousand yolks (ova) at birth. When a yolk is mature, it will be released from the ovary to the oviduct. This takes 15 minutes to half an hour, and fertilization happens here if the hen mates with a rooster. Next, the yolk travels down to the magnum and the isthmus sections of the oviduct. The inner and outer shell membranes are formed to hold the egg content together loosely. It takes about 2-4 hours. After that is the most time-consuming part: forming the eggshell. The shell gland in the...