AAMC Biology Question Packs 1&2 Flashcards
What are the ratios of Na+ and K+ in reference to the sodium potassium pump?
3 Na+ per 2k+
The term “a neuron is like a salty banana” is in reference to what?
At resting potential, the K+ ions are inside the neuron while the Na+ are on the outside.
What is the definition of action potential?
Increased permeability of the plasma membrane to sodium
What is the difference between germ and somatic cells?
Somatic cells are cells that have differentiated and make up all the cells of our body, while Germ cells differentiate into gonads, ultimately making up the testes and ovaries
What is hemolysis?
rupture of red blood cells
The checkpoints within the cell cycle are performed by what?
Cyclin dependent kinases and cyclins.
CDK are always present in the cell and certain cyclins are produced depending on what stage the cell is in the cell cycle.
The splitting of the centromere occurs when in mitosis and meosis?
It occurs in the anaphase portions of Mitosis and Meiosis 2 but NOT Meiosis 1.
What will increase the glomelular filtration rate?
An increase in blood pressure will increase the flow of fluid through the kidney system increasing glomelular filtration rate.
Kidney:
What is the function of aldosterone?
Produced in the adrenal cortex, it causes Na+ absorption by kidney tubules. This increases blood volume and pressure because H2O passively follows Na+ and results in H2O absorption into the blood stream
Kidney:
What is the function of erythropotein?
Produced by the kidney during periods of hypoxia to stimulate RBC production to increase oxygen carrying compacity.
Kidney:
What is the function of Renin?
Renin converts angiotensin to angiotensin 1 which travels to the lung and is converted by ACE to Angiotensin 2 which then increases blood pressure.
Kidney:
What is the function of calcitriol?
Cacidiol produced by the parathyriod it is converted to Calcitriol by the kidney with the help of PTH.
Increases Ca2+ and Po4- absorption in intestine
Induces immune cell differentiation in immune system
Increases reabsorption of Ca+ in nephron
Why does the concentration of cyclin oscillate between interphase/mitosis/interphase/mitosis/etc?
Cyclin is made at specific times to activate CDK during the cell cycle. It inactivates RB which allows cellular replication to occur.
After this replication, these kinases undergo proteolysis during mitosis.
Bacteria and Eukaryotic cells both produce ATP via?
ATP synthase
An autosome is?
any chromosome that is not a sex chromosome (x or y)
A deficiency in aldosterone would cause?
A decrease in both blood volume and blood pressure
What is derived from the ectoderm?
Epithelial tissue, lining for all hollow organs, nerve tissue, salivary glands, mucous glands of nose and mouth
What is derived from endoderm?
lining of the digestive tract, parenchyma of liver, lining of pharynx and respiratory tract, epithelium of bladder and urethra
What is derived from mesoderm?
muscles, fibrous tissues, bone and cartilage, fat (adipose tissue), blood and lymph vessels, blood cells
Where is glycogen broken down?
the liver
Vital capacity is?
the maximum amount of air that can be breathed out after breathing in as much as possible
Breathing rate is?
the number of breaths per minute
Tital volume is?
amount of air breathed in with each normal breath
Minute ventilation is?
the total volume of air entering the lungs per minute
Dead space is?
the total volume of air that does not participate in gas exchange
Total dead space is?
Total dead space=Anatomical + Aveolar Dead space
What are the benefits of vasodilation in a hot enviroment?
aids in cooling by allowing the blood to bring heat to the surface of skin where it can be lost via radiation
When discussing if a bacteria or a virus is more potient what would you look for?
The smaller number that would cause an infection.
less bacteria/virus it takes to cause infection=more potient
How does Antibiotic resistance occur?
Antibiotic resistance occurs when a bacteria mutates and all other bacteria without the mutation are killed by the antibiotics. Then the antibiotic resistance bacteria repopulates the area
If a drug is blocking the re-uptake of a NT into a nerve terminal what occurs?
There will be more NT within the synaptic cleft, which will cause the body to have a greater response to that NT
When breathing in-what occurs?
the diaphram will contract creating reduced pressure and the external intercoastal rib muscles will help chest expand
How are virons formed?
virons are formed by budding off the surface of a eukaryotic cell become enclosed in a vesicle composed of the host’s membrane
What is the limit resolution on a light microscope?
200 nm
Bacteriophages are?
viruses enclosed in bacteria
How does the body avoid autoimmune reactions?
To avoid autoimmune reactions the body supresses cells that are specific to it’s own antigens
Where is the pleural cavity?
The space between the pluera (thin membranes of the lungs)
Where is the peritoneal cavity?
space between the parietal peritonum (surrounds abdominal wall) and the visceral peritoneum (peritoneum that surrounds the internal organs)
What is adaptive radiation?
The divergence of one species into multiple species over time
When does adaptive radiation occur?
It occurs when subgroups of the original species are separated or isolated in different enviroments so these subgroups evolve independently of one another
Calcitonin _______________ calcium levels in blood, while parathyroid hormone _____________ calcium levels in blood.
Calcitonin reduced calcium levels in blood, while parathyroid hormone increases calcium levels in blood.
What is a female ovum?
Female gamete that has completed meiosis containing the haploid number of maternal chromosomes
Endocrine glands secrete their hormones through __________ while exocrine hormones secrete their hormones through _________.
Endocrine glands secrete their hormones through the blood while exocrine hormones secrete their hormones through ducts.
What are the purines?
Guanine and Cytosine
What are the pyrimidines?
Adenine and Thymine
In vitro is a term for research done _______ the body, while in vivo is a term for research done ______ the body.
In vitro is a term for research done outside the body, while in vivo is a term for research done inside the body.
TIP: Remember in vitro fertilization is fertilization done in a lab
Where does transcription occur in Prokaryotic cells?
In the cytoplasm since prokaryotes don’t have nuclei
What is a primary oocyte?
Oogonia that at birth have already undergone DNA replication so they are 2n arrested in prophase 1
What is a secondary oocyte?
The term for when at menstruation a primary oocyte completed meiosis 1 producing a 2ndary oocute and a polar body
A polar body is created by?
Unequal cytokinesis
What is the zona pellucida?
the accellular glycoprotiens combined with compounds necessary for sperm binding.
What is the corona radiata?
Layer of cell adhered to the oocyte during ovulation outside the zona pellucida
What occurs when the sperm penetrated the secondary oocyte?
It then undergoes the 2nd meiotic division to split into the mature ovum and polar body
What is the result of spermatogenisis?
Spermatogenesis results in 4 functional sperm for each spermatogonium
A spermatogonium is a?
diploid stem cell
A primary spermatocyte is?
A diploid sperm cell that has replicated it’s genetic material (S stage)
A secondary spermatocyte is?
A haploid sperm cell that has undergone it’s first meiotic division
What is a spermatid?
Haploid sperm cells that have undergone Meiosis 2
What is a spermatozoa?
Spermatids that have undergone maturation
What is a cortical reaction?
When the sperm penetrates the ovum, it releases a flood of calcium ions that prevent further fertilization of the and increases metabolic rate of zygote
The term zygote refers to?
the unicellular ovum + sperm
Meosis 2 is triggered in the secondary oocyte when?
Meiosis 2 is triggered when sperm cell penetrates the zona pellucida and the corona radiata
What is cleavage?
rapid mitotic divisions as a zygote moves to uterus for implantation
When does the zygote become an embryo?
After the 1st cleavage.
A morula is?
When the embryo becomes a solid mass of cells
What is blastulation?
The process of forming a blastula, where the morula transforms into a hollow ball of cells with a fluid filled inner cavity known as a blastocoel
What are the two groups in a blastocyst?
Trophoblasts that surround the blastocoel that give rise to the chorion and then later the placenta
Inner cell mass that protrudes into the blasteocoel that gives rise to the organism itself
What is gastrulation?
The generation of 3 distinct cell layers occuring after implantation
Assuming fertilization occurs name the terms for the female reproductive stages from birth to implantation?
Primary oocyte->secondary oocyte->mature ovum->zygote->embryo->blastocyst->gastrula
