SCD and DSD

Question 1

Sickle cell hemoglobin and malaria

Answer 1

Malaria resistance due to the plasmodium parasite not being able to infect the host because sickle cells die easily.

Question 2

Sickle cell and climate change

Answer 2

Due to oxygen levels dropping quickly, sickle cells crisis will occur very often and create a crisis sue to RBC sickling and blocking oxygen and blood flow.
As climate change, increased in temperature allows mosquitoes to breed at higher altitude.

Question 3

Sickle cell shape and blood vessels

Answer 3

When RBC sickle, they now can’t go through blood vessels as well and therefore lead to blockage of blood flow which impairs oxygen delivery to the body,

Question 4

Anemia

Answer 4

sickle cells lead to shortage of red blood cells

Question 4

Fetal hemoglobin vs adult hemoglobin

Answer 4

alpha and gamma chains have a higher affinity for oxygen, suck oxygen out of the mother’s body
alpha and beta chains are found in adult hemoglobin

Question 5

Sickle cell disease

Answer 5

Genetic condition that causes anemia while preventing malaria

Question 5

Hydroxyurea

Answer 5

Increases the production of fetal hemoglobin which stops the polymerization of sickle cells, increase of gamma units

Question 6

Treatments for SCD

Answer 6

Blood transfusions to increase red blood cells counts.
Bone narrow transplant which is the only permanent cure which is where red blood cells come from

Question 6

Penicillin

Answer 6

Blocks out infection and treat them so helps when the spleen is dysfunctional due blockage of red blood cells causing brushing easily

Question 7

Erythrocytes contain large amounts of hemoglobin which transport oxygen and carbon dioxide

Answer 7

4 subunits, globin proteins that have iron, they are very shallow centers that optimizes surface area to volume to facilitate gas exchange and move through narrow blood vessels.
RBC have a short life spam

Question 8

Hypoxic environment

Answer 8

Oxygen deficiency due to change in high altitude, respiratory diseases, anemia, reduced blood flow and cyanide poisoning.

Question 9

Plasma concentration

Answer 9

90% water
Proteins
Kwashiorkor
Nitrogenous waste
Electrolytes
Respiratory gases
Nutritents

Question 9

What are the formed elements of blood

Answer 9

They include both cellular and acellular structures
Erythrocytes which are red blood cells begin in red bone narrow
Leukocytes which are white blood cells
Platelets

Question 9

Sickle cells is a hematological condition
Functions of the blood?

Answer 9

Blood carry nutrients and oxygen to the body

Question 10

Hematocrit

Answer 10

Counts of red blood cells in plasma which can detect dehydration ( less water, more cells) and anemia .

Question 11

Anemia

Answer 11

Low iron level which leads to sickled cells blocking blood flow in small vessels

Question 11

Tonicity affects the likelihood of sickling

Answer 11

Under hypertonic sodium solution, water will leave the cell and increases sickling leading to occlusion and adhesion which is under normoxic or hypoxic conditions.

Question 12

Draw the inheritance pattern of SCD

Question 12

Sickle cell disease

Answer 12

A mutation in hemoglobin beta subunit which results in an abnormal form of hemoglobin. Under hypoxic conditions, RBC sickles and crystalize with each other and that reduces the oxygen delivery to the body and make them prone to breaking apart easily.

Question 12

Treatments

Answer 12

Blood transfusions to increase RBC counts and decreased sickle cells counts
Hydroxyurea- increase fetal hemoglobin
Gene therapy and gene editing
Bone narrow transplant- only curable treatment, replacing bone narrow where erythrocytes are made.

Question 12

Symptoms of SCD and how this relates to the mutation

Answer 12

Pain crisis due to blood flow blockage from sickled cells because of the beta subunits being able to crystallize and stick to blood vessels
Anemia- Low count of red blood cells due to rapid breakage because of the sickled shape
Swelling of hands and feet
Spleen damage due blockage of blood flow and that can lead to infections very easily

Question 13

Evolutionary advantage of SCD

Answer 13

SCT is advantageous in people living in malaria endemic area because they have higher resistance to malaria due to sickle cells dying before plasmodium can infect the host.
Heterozygous advantage.

Question 14

What kind of mutation is SCD and how does it affect hemoglobin structure

Answer 14

A point mutation that is due from T to A change which changes the amino acid from glutamic acid to Valine, a non-conservative missense mutation.
The beta subunits will crystallize into fiber with one another and the capacity to carry oxygen and it’s easier to block blood flow in vessels.

Question 15

SDS can be caused by..

Answer 15

Structural changes and chemical changes

Question 15

Structural changes by non-disjunction

Answer 15

In meiosis 1, nondisjunction lead to 2 gametes with 3 chromosomes and 2 gametes with 1 chromosomes
In meiosis 2, nondisjunction lead to gametes with 3 chromosomes, 1 chromosomes and 2 gametes with 2 chromosomes.

Question 16

Trisomy 21

Answer 16

Down syndrome lead to 3 extra copies of chromosome 21

Question 17

Trisomy 13

Answer 17

Patau syndrome with extra digits, harelip, single eye which is 3 copies of chr 13
Life expectancy 130 days.

Question 18

DSD due to both chemical and structural events

Answer 18

At first, sex is undetermined then female or male genitals appear
The adrenal cortex uses cholesterol to make androgens and genital structures develop due to the presence/absence of DHT.

Question 18

Guevedoce, 5-AR enzyme, a chemical difference

Answer 18

causes pseudo hermaphroditism in males
5-AR enzyme can’t convert testosterone to DHT which then leads to female hormones production

Question 19

Female pseudo hermaphroditism

Answer 19

21 alpha hydroxylase malfunction
Hypo cortisol lead to adrenal androgens because progesterone can’t be converteed to cortisol and the pathway to adrenal androgens occurs.

Question 19

DSD by structural diff due to nondisjunction

Answer 19

X0 = turner syndrome, infertile woman with broad shoulders and spaced out nipples

Question 20

AIS androgen incendivity syndrome

Answer 20

A male that has female morphology which is due to a receptor mutation, X linked recessive,.