Is Spiderman’s Blood Red or Blue?
Except for the icefish, all known vertebrates have red blood. (A vertebrate is an animal with backbones.) The red color occurs when oxygen binds to an iron group on hemoglobin. Hemoglobin is the oxygen-carrying molecule in red blood cells. Red blood cells (RBCs) with a lot of oxygen are bright red, while RBCs with little oxygen (deoxygenated) are deep red.
Wait, isn’t deoxygenated blood blue?
No, it is a deep red. Squid, octopi, crustaceans, and spiders have blue blood.
So does Spiderman have blue blood?
Umm, probably not since he is more man than a spider. However, a few people have done some research on the topic.
Interesting, but I am a little disturbed.
Why?
Because there are more people like you in the world.
Yep, we’re a population.
Anyway, why is human blood red and spider blood blue?
The blood color is dependent on the binding of oxygen to the oxygen-carrying molecule. A spider’s blood cells contain hemocyanin, which turns blue in the presence of oxygen. Other animals have oxygen-carrying molecules that turn green (leeches) or violet (certain types of worms) when oxygen is present.
Fun fact: leprechauns have rainbow blood.
Leprechauns are not real.
Tell that to Lenny the Leprechaun and his magical rainbow blood.
I need to stop speaking to you.
He’s part level 48 dragon.
Anyway, all vertebrates have red blood except the icefish. The icefish has transparent blood; therefore, no hemoglobin.
I’m afraid to ask, but how does the icefish transport oxygen if it does not have hemoglobin?
Oxygen dissolves directly into the icefish’s plasma (liquid portion of the blood) and transports throughout the body tissues.
So, what caused the icefish to lose hemoglobin?
It was a . . .
Please don’t say dragons. Please don’t say dragons. Please don’t say dragons.
No, it’s not dragons. The icefishes’ transparent blood is the result of a single gene mutation, and ‘agh.
Isn’t ‘agh Klingon for dragon?
Chaq.
Gene Mutations
In the evolution unit, you learned that mutations are the source of new alleles. Mutations may benefit, hurt, or have no effect on an organism’s fitness. In most situations, a mutation that leads to the loss of hemoglobin would be detrimental and result in an organism’s death. However, in the icefishes’ environment, the loss of hemoglobin increased its fitness, giving it an advantage in the Antarctic Ocean’s icy waters.
Point Mutations
A point mutation changes a single nucleotide in a gene, affecting the protein the gene codes for. Below is a linguistical analogy of a point mutation where the change of a single letter alters the word (protein).
Substitution Point Mutations
Substitution mutations occur when one nucleotide is substituted for another. The substitution may or may not have a noticeable effect on the gene.
Example 1 demonstrates a silent gene mutation. The third nucleotide (A) of a codon was substituted with a C. However, the codon GGA and GAC code for the amino acid glycine. Therefore, this mutation had no direct effect on the coding of the gene’s protein.
Example 1
In example 2, the first nucleotide (G) of a codon was substituted with a C, changing the codon from GGA to CGA. CGA codes for a different amino acid, arginine. Therefore this will affect the structure and function of the mutated gene’s protein.
Example 2
Frameshift Point Mutations
Frameshift mutations always lead to the destruction of a gene and are almost always harmful to an organism. There are two types of frameshift mutations:
- A deletion frameshift mutation happens when a single nucleotide is deleted. The deletion causes the gene’s entire code to move to the left, altering the entire amino acid sequence from the mutation point.
- An insertion frameshift mutation happens when a single nucleotide is inserted. The insertion causes the gene’s entire code to move to the right, altering the entire amino acid sequence from the mutation point.
A frameshift mutation is what led to the destruction of the ice fishes’ hemoglobin gene.
Mutating a Sentence
Below are examples on how a point mutation can alter a sentence’s meaning.
Chromosome Mutations
Chromosome mutation occurs when many genes within a chromosome are changed. Chromosome mutations are always harmful to an organism and usually lead to death or severe disabilities.
AP Bio Prep
Click here for a more in-depth look at gene mutations.