EOC – Unit 3
Sickle cell disease, passed down through families, is the result of an abnormal type of hemoglobin,
which causes red blood cells to be crescent-shaped instead of circular.
There are three main health problems that are associated with sickled red blood cells.
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RBCs break into pieces easily
less oxygen delivered
get stuck in small blood vessels
A blood deficiency in red blood cells, hemoglobin, or total volume that is caused by sickle cell disease is
called sickle cell anemia.
Hematocrit tests are used in diagnosing anemia.
A hematocrit determines what percentage of the volume of whole blood is composed of red blood cells.
If someone has a low percentage of red blood cells in their plasma after centrifugation, they are anemic.
The effects of sickle cell disease are as follows.
 more prone to blood clots
 increased susceptibility to bacterial and viral infections
Blood plasma is the pale yellow fluid portion of whole blood, made up of 90% water and 10% proteins.
Red blood cells (erythrocytes) contain hemoglobin, carry oxygen to tissues, take carbon dioxide back to
the lungs to be exhaled, and are responsible for the red color of vertebrae blood.
White blood cells, or leukocytes, the colorless blood cells that lack hemoglobin and contain a nucleus,
are responsible for destroying bacteria, producing antibodies against bacteria and viruses, and fighting
malignant diseases. Types of white blood cells include lymphocytes, monocytes, neutrophils,
eosinophils, and basophils.
A minute colorless anucleate with no nucleus and a disk-like body of mammalian blood is called a
platelet, or a thrombocyte. Its main function is to interact with clotting proteins to stop or prevent
bleeding.
The DNA code is an arrangement of nucleotides (A, T, C, and Gs) that dictates everything we are
genetically and controls our entire bodies, as they dictate what proteins our bodies produce.
Proteins produce all of our genetic traits.
Proteins are produced when maternal and paternal cells go through meiosis and alleles are inherited
randomly. These alleles then code for certain proteins.
The sequence of nucleotides in DNA determines the sequence of amino acids in a protein, because the
sequence of nucleotides in transcribed into the sequence of amino acids, which translate into proteins.
A mutation is when just one nucleotide is not what it should be.
The building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous
base and a phosphate group is called a nucleotide.
The environment around it, the amino acids present, and the order of amino acids are what determine a
protein’s shape.
An organic monomer which serves as a building block of proteins is called an amino acid.
An anticodon is a triplet of nucleotide bases in transfer RNA that identifies the amino acid carried and
binds to a complementary codon in messenger RNA during protein synthesis at a ribosome.
A three-nucleotide sequence of DNA or mRNA that specifies a particular amino acid or termination
signal; the basic unit of the genetic code is called a codon.
If something is hydrophilic then it has an affinity for water, but if it is hydrophobic then it has an
aversion to water.
Messenger RNA, or mRNA, is a type of RNA, synthesized from DNA and attached to ribosomes in the
cytoplasm that specifies the primary structure of a protein.
Steps of Protein Synthesis
1.
2.
3.
4.
5.
6.
7.
DNA info copied onto mRNA strand
As, Cs, Gs, and Us (replacing Ts)
mRNA leaves nucleus for cytoplasm
ribosome attaches to mRNA
tRNA brings amino acids
amino acid sequences match with mRNA
ribosome assembles amino acids into proteins
Ribonucleic acid (RNA) is a type of nucleic acid consisting of nucleotide monomers with a ribose sugar
and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-stranded;
functions in protein synthesis and as the genome of some viruses.
A ribosome is a cell organelle that functions as the site of protein synthesis in the cytoplasm; consists of
ribosomal RNA and protein molecules and is formed by combining two subunits.
When RNA is synthesized on a DNA template, it’s called transcription.
Transfer RNA, or tRNA, is an RNA molecule that functions as an interpreter between nucleic acid and
protein language by picking up specific amino acids and recognizing the appropriate codons in the
mRNA.
The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a
change of language from nucleotides to amino acids is called translation.
DNA is passed to new cells during cell division through mitosis.
Any of the usually linear bodies in the cell nucleus that contain the genetic material can be defined as
chromosomes.
Any of the alternative forms of a gene that may occur at a given locus are called alleles.
An autosome is a chromosome that is not directly involved in determining the sex of an organism.
A genetic trait is considered to be a dominant trait if it is expressed in a person who has only one copy
of the gene associated with the trait.
A gene is a discreet unit of hereditary information.
Molecules that are responsible for heredity and variation of organisms are defined as genetic material.
A genotype is all or part of the genetic constitution of an individual or group.
Heredity is the transmission of traits from ancestor to descendant.
Meiosis is the cellular process that results in the number of chromosomes in gamete-producing cells
being reduced to one half and that involves a reduction division in which one of each pair of
homologous chromosomes passes to each daughter cell.
A process that takes place in the nucleus of a dividing cell, involves a series of steps, and results in the
formation of two new nuclei each having the same number of chromosomes as the parent nucleus is
known as mitosis.
Homologous chromosomes are chromosomes having the same or allelic genes with genetic loci usually
arranged in the same order.
A display of the chromosome pairs of a cell arranged by size and shape is called a karyotype.
Pedigrees are diagrams of a family tree showing the occurrence of heritable characteristics in parents
and offspring over multiple generations.
A phenotype is the observable properties of an organism that are produced by the interaction of the
genotype and the environment.
A recessive trait is a condition that appears only in individuals who have received two copies of a
mutant gene, one copy from each parent. An example of a recessive trait is sickle cell disease.
A simple graphical way of discovering all of the potential combinations of genotypes of an offspring,
given the parents’ genotypes is called a Punnett square.
Doctors and genetic counselors are able to examine the genetic codes of the parents and then make
Punnett squares to predict how their traits will transfer to their offspring, calculating the probability that
a child will inherit a disease.
Where there is malaria, there is generally a large amount of people who suffer from sickle cell disease,
because their sickled cells protect them from malaria, because the shape makes it harder for the
parasite that causes malaria, plasmodium, to survive.