Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MCAT prep > Biology: systems > Flashcards

Biology: systems Flashcards

1
Q

What can cause speciation?

A
  • Inbreeding
  • Bottleneck (drastic even wipes out most alleles in gene pool, leaving only a few that are not represenatative of population before)
  • Specialization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe Hardy Weinberg equilibrium, and its 5 points.

A

HW equilibrium = NO evolution occurs

  1. mutational equilibrium (forward mutation = backward mutations)
  2. Large population (avoid genetic drift)
  3. random mating
  4. no immigration/emmigration
  5. no selection of fittest organism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Differentiate of viruses get into bacteria vs. eukaryotes>

A
  • bacteria = injects its nucleic acids through a tail after digesting hole in membrane
  • eukaryotes = viruses engulfed by host cell via endocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Differentiate a lytic and lysogenic infection

A
  • Lytic = take hold of host cell and use their RNA (or transcribed from viral DNA) to create new viruses until they burst or release one by one
  • Lysogenic = viral DNA incorporated into host genome, therefore can stay dormant until activated (then go into lytic)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are viral envelopes and how are they beneficial?

A

envelopes created by host ell membrane that the virus has pinched off and used
-beneficial because protects virus from immune response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which viral RNA needs an RNA-dependent RNA polymerase?

A

The -RNA, as it creates a complimentary strand that does not code for any proteins, then it undergoes replication by the polymerase to create a +RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a retrovirus?

A

a virus that uses a reverse transcriptase to transcribe RNA into dsDNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the difference between gram (+) and gram (-) bacteria?

A 
(+) = thick cell wall, so doesn't let stain out - stained PURPLE
(-) = thin cell wall, allows stain to be washed - stained PINK, also has another membrane on top of cell wall that protects from antibiotic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 3 different types of genetic recombination?

A
  1. Conjugation: transfer of plasmids (F and R plasmids)
  2. Transformation: DNA from external into bacterial genome
  3. Transduction: transfer genetic material from a virus using a vector
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The nucleolus is where…?

A

Where ribosomal DNA is transcribed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are lysosomes filled with?

A

acid hydrolyses, with a pH of 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the functions of smooth endoplasmic reticulum?

A

Lipid metabolism, storage and detoxification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the functions of peroxisomes?

A

Lipid and protein storage. They also produce and breakdown hydrogen peroxide.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the 3 parts of the cytoskeleton.

A
  1. Microtubules - for transport and support shape of the cell. Make from tubulin.
  2. Microfilaments - Contraction and cleavage. Made from actin.
  3. Intermediate filaments - maintain cell shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the important checkpoints in the cell cycle?

A

G1 checkpoint: checks ratio of DNA:cytoplasm

G2 checkpoint: checks for mitosis promoting factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the cell cycle and its 4 points.

A

G1: cell growth after dividing
G0: non-growing state (neurons)
S: DNA replication
G2: prepare to divide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the differences between the 3 different connections between cells? And an example.

A
  • Tight junctions: water tight seal. Ex. epithelial in bladder, kidney and intestines
  • Desmosomes: joined via the cytoskeleton. Ex. stressed tissues.
  • Gap junctions: tunnels connecting cells. Ex. cardiac and smooth muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What photoreceptors are for colour? for black and white?

A

colour = CONES!

black and white = RODS!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When the ciliary muscles in the eye CONTRACT what happens?

A

Lens becomes more sphere and the focal point is closer the the lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When the ciliary muscles in the eye RELAX what happens?

A

Lens becomes flattened and increases the focal distance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How is the resting potential of a neutron created?

A

Through the diffusion of K+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the difference between parallel and convergent evolution?

A

Convergent evolution: when species of different ancestry develop the analogous traits due to similar enviro’s/niches
Parallel evolution: when 2 species evolve independently of each other but remain the same level of similarity. This is NOT due to similar enviros, and it it usually 2 unrelated species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where are peptide hormones formed? What are they made out of?

A

In the rough endoplasmic reticulum. They are mostly amino acids, but can contain carbohydrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are all the steroid hormones?

A

Cortisol, aldosterone and the androgens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where do steroid hormones bind?

A

In the cytosol, because can diffuse through the lipid membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the tyrosine derivative hormones?

A

T3 and T4, epinephrine and norepinephrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Where are the steroid hormones synthesizeD?

A

In the smooth endoplasmic reticulum and the mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Where are the tyrosine derivative hormones synthesized?

A

In the cytosol or the rough endoplasmic reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the job of antidiuretic hormone (vasopressin) and where is it released from?

A
  • Fluid is reabsorbed, and blood pressure is increased

- released from the post. pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Where is oxytocin released from?

A

The post. pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Parathyroid hormone works to______ Ca2+ by _________ the osteoclasts.

A
  • Increase blood Ca2+

- proliferating osteoclasts (and excretion of phosphate and reabsorbing Ca2+ at kidney level)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Calcitonin hormone works to______ Ca2+ by _________ the oteoclasts

A
  • Decrease blood Ca2+

- inhibiting osteoclast activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is aldosterones job in the body?

A

Causes Na+ and Cl- reabsorption and K+ excretion which works to increase blood pressure

34
Q

In male reproduction the Sertoli cells are stimulated by -_________ and their job is to…?

A
  • follicle stimulating hormone

- surrond and nurture the sperm

35
Q

In male reproduction the leading cells are stimulated by __________ and cause production of….?

A
  • luetinizing hormone

- testosterone

36
Q

In female reproduction the granulose cells are stimulated by______ to do what?

A
  • follicle stimulating hormone

- to create the primary follicle

37
Q

In female reproduction the theca cells are stimulated by _______ to produce…?

A
  • luetinizing hormone

- estradiol

38
Q

What is released by the placenta to regulate the estrogen and progesterone levels when pregnant? What type of hormone is it?

A

-human chorionic gonadotropin (HCG) and it is a peptide hormone.

39
Q

Differentiate the 3 germ layers and what they create (ecto-, meso-, and endoderm)

A

Ecto- skin, NS, sense organs
Meso- skeleton, muscles, heart, blood, gonads, kidneys and dermis of skin
-endo- lining of digestive and respiratory tract, liver, pancreas, thymus and thyroid

40
Q

When does air flow into the respiratory system? Out of?

A

When the gauge pressure inside is LESS than atmosphere (gauge pressure is negative). When gauge pressure is GREATER than atmospheric pressure, air flows out

41
Q

In the lungs, does O2 or CO2 have the highest partial pressure?

A

O2 is higher than CO2!! Because it promotes CO2 transfer into alveoli

42
Q

In the capillaries, does O2 or CO2 have the highest partial pressure?

A

CO2 is a bit higher than O2!! Because it promotes O2 into transfer

43
Q

What causes a rightward shift in a hemoglobin oxygen dissociation curve? What does a rightward shift mean?

A

An INCREASE in CO2 or temperature, and a DECREASE in pH.

-means all of these cause a lower affinity for oxygen

44
Q

How does 2,3-DPG help in high altitudes?

A

Lowers hemoglobins affinity for oxygen to offload )2 into tissues

45
Q

What is the enzyme that catalyzes the reaction:

H2O + CO2 HCO3- + H+

A

carbonic anhydrase

46
Q

How does Cl- help with the reaction?

A

it is exchanged with bicarbonate ions that build up so that the blood is not too negatively charged

47
Q

What will happen when the blood is too acidic?

A

The body will INCREASE breathing to expel CO2 and raise the pH of blood back up

48
Q

Differentiate between granular and agranular leukocytes.

A

Granular ones live for a short time because they function nonspecifically against all infections and then die.
Agranular cells live long time to watch for repeat infections

49
Q

What is innate immunity? What cells are involved?

A

It is quick and NONspecific.

Phagocytes: macrophages and neutrophils, and monocytes or eosinophils

50
Q

What are the 2 types of acquired immunity?

A

B and T cell

51
Q

What is B cell immunity?

A

Humoral
-involves B lymphocytes that make a singe antibody that corresponds to an antigen, then when recognizes it, releases plasma cells and memory B cells

52
Q

What are the different ways that B cells promote destruction of foreign antigen particle?

A
  • phagocytosis via natural killer cells/macrophages
  • perforate antigen cell
  • antigen cells to stick together or precipitate
  • attach to mast cells and then release histamine
53
Q

What is T cell immunity?

A

Cell mediated
-Involves T lymphocytes that also make antibodies, but when recognition happen, produce Killer, Memory and Suppressor T cells

54
Q

Differentiate between MHC class 1 and 2 on cells.

A 
MHC class 1 = display antigens from intracellular pathogens via endogenous pathway 
MHC class 2 = display antigens from extracellular pathogens, so only expressed on phagocytes via exogenous pathway
55
Q

What is the difference between positive and negative selection of immunity regulation?

A 
(+) = when B and T cells cannot recognize MHC class 1 or 2 cells are destined for apoptosis 
(-)= when B and T cells respond too strongly to MHC molecules with self-antigens are destined for apoptosis
56
Q

What does alpha-amylase do?

A

Cleaves alpha-1,4 glycosidic bonds of carbohydrates in the mouth

57
Q

Where is pepsin seen in the digestive system? What does it do?

A

In the stomach, it breaks down proteins

58
Q

What are the 4 types of cells present in the stomach?

A
  1. Mucous cells
  2. Chief cells - secrete pepsinogen
  3. Parietal cells - secrete HCl
  4. G cells - secrete gastrin that stimulates. HCl
59
Q

Digestion happens in the _____ and absorption happens in ________

A 
digestion = duodenum
absorption = jejunum and ileum
60
Q

What does the pancreas secrete in regards to exocrine function?

A
  • bicarbonate (neutralize HCl)
  • trypsin and chymotrypsin
  • carboxypolypeptidase (break down proteins)
  • pancreatic amylase (breakdown carbs)
  • lipase (break down fats)
61
Q

The large intestine is primarily responsible for..? (2 things)

A

Water absorption and electrolyte absorption

62
Q

What are the 3 main gastrointestinal hormones?

A
  • Secretin: stimulates pancreas to release sodium bicarbonate to start digestion
  • Gastric Inhibitory polypeptide: decrease motor activity in the stomach
  • Cholecystokinin: gall bladder contract and pancreas secretion
63
Q

What are the metabolic functions of the liver?

A
  • Carb metabolism
  • Fat metabolism
  • protein metabolism
  • detoxification
64
Q

When the liver mobilizes proteins/fats for energy, what happens to the pH of blood?

A

decreases

65
Q

What compounds does the liver store?

A
  • glycogen
  • blood
  • vitamins
66
Q

What are the immune functions of the liver?

A
  • Blood filtration

- erythrocyte destruction

67
Q

What forces substances through the glomerulus to bowmans capsule in the kidneys

A

hydrostatic pressure

68
Q

What happens in the proximal tubule of the nephron?

A

secretion of H+ and reabsorption of toxins and other molecules

69
Q

The descending loop of Henle has…?

A

Low permeability to Na+ and high permeability to water

70
Q

the ascending loop of Henle has…?

A

High permeability to solutes and Impermeable to water

71
Q

What does aldosterone act on and how does it show its affects?

A

Acts on the distal tubule; it increases the Na/K pumps to INCREASE blood pressure

72
Q

What does anti-diuretic hormone act on and how does it show its affects?

A

Acts on the end of the distal tubule and the collecting duct; it causes increases reabsorption of water to INCREASE blood volume

73
Q

At the distal tubule, which solutes are moved?

A

Na and K are reabsorbed, where K, H and HCO3 are secreted

74
Q

The collecting duct is ______to water?

A

impermeable

75
Q

What part does Calcium play in muscle contraction?

A

Binds to troponin which moves tropomyosin to expose a site for myosin to bind

76
Q

What part does ATP play in muscle contraction?

A

Causes myosin to release tropomyosin and stop the power stroke

77
Q

What is oxygen debt?

A

The need for increased O2 after exercise to metabolize lactic acid build up

78
Q

Why do type 1 (slow twitch) muscle fibres have lots of mitochondria

A

because produce a lot of energy in an oxidative environment so they can be resistant to fatigue

79
Q

What is the plateau in the heart muscle contraction due to?

A

slow voltage gated Ca2+ channels; helps the heart from beating too quickly

80
Q

Spongy bone is where____ develop, and compact bone is what holds ____?

A
  • Red blood cells

- yellow marrow (fat cell storage)

81
Q

What are the normal homeostatic levels of calcium in the body?

A

high concentration outside and low concentration inside cells

82
Q

Which type of joints provides NO movement? SLIGHT movement? MORE movement?

A

NO - fibrous
SLIGHT - cartilaginous
MORE - synovial

MCAT prep (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions