Brainscape's Knowledge GenomeTM

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


See full index

MCAT > Biology Flashcards > Flashcards

Biology Flashcards

You may prefer our related Brainscape-certified flashcards:
MCAT flashcards
1
Q

evolution

A

process whereby the gene pool of a species changes over time b/c individuals with more desirable genes are selected for by the environment

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

species

A

group of organisms which are capable of reproducing with one another and producing viable offspring

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

natural selection

A

“survival of the fittest” which demonstrates a relative increase in the reproduction of organisms which have traits that are better suited for their environment, due to 3 principle: variation, inheritance, competition

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

variation

A

individuals within a population will have different traits

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

inheritance

A

offspring inherit traits from their parents

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

competition

A

more offspring are produced than can survive, so offspring with traits better suited to the environment will survived and have more offspring than individuals with less desirable traits

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

group selection

A

idea that natural selection sometimes acts on whole groups of organisms, favoring some groups over others leading to the evolution of traits that are advantageous to the group

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

speciation

A

Occurs when some kind of barrier prevents successful interbreeding between members of a species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

allopatric speciation

A

occurs when the reproductive barrier is geographic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

sympatric speciation

A

occurs when 2 populations become genetically distinct when living in the same location, b/c they have adapted to different elements of the same location or b/c they have developed unique mating behaviors

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

adaptation

A

process by which a population gradually develops traits that are better suited to a particular habitat

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

genetic diversity is affected by:

A

mutations, inbreeding, outbreeding, and genetic drift

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

inbreeding

A

increases the proportion of individuals with homozygous genotypes, therefore increasing the number of homozygous recessive phenotypes that are harmful

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

outbreeding

A

increases genetic diversity by promoting reproductive fitness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

genetic drift

A

random changes in the diversity and/or number of alleles present in a population, usually decreases genetic diversity: can result in bottleneck or founder effect

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

bottleneck

A

crisis randomly kills a large portion of a population and decreases genetic diversity

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

founder effect

A

few members of a population move to a new habitat and the new population has a smaller gene pool with less diversity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

carbohydrates of a plasma membrane

A

found on the exterior surface of cells and are bound to either proteins (forming glycoproteins) or to lipids (forming glycolipids)

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

waxes

A

composed of a long-chain FA bonded to an alcohol group, contribute to rigidity in the cell membrane and provide structure

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

transbilayer diffusion

A

when a phospholipid “flip-flops” to the opposite layer

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

flippase

A

brings a phospholipid from the outer leaflet to the inner leaflet

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

floppase

A

brings a phospholipid from the inner leaflet to the outer leaflet

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

scramblase

A

brings a phospholipid from the outer leaflet to the inner leaflet and a phospholipid from the inner leaflet to the outer leaflet
(doesn’t require ATP)

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

osmolarity

A

describes the total solute concentration of the solution which gives rise to osmotic pressure
(ex: high osmolarity: fewer water molecules with respect to solutes)

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

secondary active transport

A

uses one electrochemical gradient to move different molecules against their own concentration gradients (aka cotransport)

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

channel proteins

A

very selective and accept only 1 type of molecule for transport

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

facilitated diffusion

A

diffusion for substances that cannot cross the phospholipid bilayer due to their size and/or polarity

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

acquaporins

A

channel proteins that allow water to cross the membrane very quickly

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

cell-surface receptors can be either

A

ion channel-linked receptors, GPCRs, or enzyme-linked receptors

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

endocytosis

A

active transport that moves particles into a cell

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

phagocytosis

A

large particles that are taken in by a cell, once the vesicle contain the particle is enclosed, it merges with a lysosome for the breakdown of material

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

pinocytosis

A

“cell drinking” process that takes in molecules (including water) which results in a much smaller vesicle than phagocytosis

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

gap junctions

A

channels between neighboring cells that allow for the transport of ions, water, and other substances between cells
(formed by connexons)

34
Q

tight junctions

A

create a watertight seal between 2 animal cell

35
Q

desmosomes

A

act like spot welds between adjacent epithelial cells

  • formed by cadherins: specialized adhesion proteins found on the membranes of both cells and interact in the space between them holding the membrane together
  • Ensure that cells in organs and tissues that stretch such as skin and cardiac muscle remain unbroken
36
Q

3 defining characteristics of a eukaryotic cell

A
  1. A membrane-bound nucleus
  2. A number of membrane-bound organelles
  3. Mitotic division: results in 2 daughter cells each have the same number and kind of chromosomes as the parent cell
37
Q

prokaryotes DO not have a

A

mitochondria

38
Q

mitochondria

A
  • Double-membrane organelles that contain their ribosomes and DNA
  • Matrix contains mitochondrial DNA and ribosomes, allowing mitochondria to be self-replicating
39
Q

lysosomes

A
  • Organelle that contains digestive enzymes for breaking down parts of the cell
  • “Garbage disposal”
  • Hydrolytic enzymes within the lysosomes aid the breakdown of proteins, polysaccharides, lipids, nucleic acids, and worn-out organelles
  • Active at a lower pH
40
Q

RER

A

ribosomes attached & modify proteins, also makes phospholipids for membranes

41
Q

SER

A

synthesis of carbohydrates, lipids, steroid hormones, detoxification, and storage of calcium ions

42
Q

golfi

A

Sorts and packages materials before they leave the cell to ensure they arrive at the proper destination

43
Q

perioxisomes

A
  • Lipid metabolism and chemical detoxification
  • Carry out redox reactions that break down FA and amino acids
  • Neutralize positions like free radicals that enter the body via H202
44
Q

3 protein fibers that make up the cytoskeleton

A
  1. microfilaments
  2. intermediate filaments
  3. microtubules
45
Q

microfilaments

A

used for cellular movement and give shape to the cell as well as support its internal parts

46
Q

microtubules

A

(largest) : help cell resist compression, provide a track along which vesicles move through the cell and pull replicated chromosomes to opposite ends of a dividing cell
- composed of tubulin, make up the structures of flagella and cilia

47
Q

intermediate filaments

A

contribute to cellular structural elements and are often crucial in holding together tissues like skin
-only found in certain animal cells, no roles in movement or transport

48
Q

in eukaryotes, cilia and flagella structure have this arrangement:

A

9+2 array, Motor proteins known as dyneins are attached to each of the 9 doublets, making the possible bending movement of flagella and cilia possible

49
Q

centrioles

A

2 form a centrosome, play a role in organizing the microtubules that separate chromosomes during cell division

50
Q

squamous epithelial cells are found to

A

Facilitate diffusion in tissues such as lungs or blood capillaries

51
Q

cuboidal epithelial cells are found in

A

glandular tissues throughout the body which they secrete glandular material

52
Q

columnar cells are found in the

A

respiratory tract they appear to be stratified but each cell is really attached to the basal membrane making it pseudostratified

53
Q

transition cells are found in

A

urinary system, arranged in a stratified layer but have the capability to pile up on top of each other in a relaxed, empty bladder

54
Q

domain: bacteria

A

composed of prokaryotes who have no membrane-bound organelles and make up a large proportion of living organism

55
Q

domain: archaea

A

prokaryotes who are similar to bacteria but contain genes and metabolic pathways that are more similar to eukaryotes than bacteria
They inhabit extreme environments

56
Q

prokaryotes lack a _ and instead have a

A

nucleus, circular chromosome located in a nucleoid

57
Q

bacteria cell wall is composed of

A

thick, rigid peptidoglycan that maintains the cell’s shape, protects the interior and prevents bursting during osmosis

58
Q

hypertonic solution

A

solution has a higher solute concentration than another solution
Leads to crenation (shriveling)

59
Q

hypotonic solution

A

solution that has a lower solute concentration

Leads to cell expansion and lysing

60
Q

pencillin

A

can be used to break down the peptidoglycan wall as it inhibits the construction of the bacterial cell wall, making it more likely to burst

61
Q

basic structure of a bacterial flagella

A

consists of a basal body, hook, and filament

-composed of flagellin protein that spin in solution

62
Q

binary fission

A

no genetic recombination or genetic diversity: the chromosome is replicated and the 2 resulting copies separate from one another due to the growth of the cell

63
Q

transformation

A

prokaryote takes in DNA found in its environment that is shed by other prokaryotes

64
Q

transduction

A

used bacteriophages to integrate viral/host DNA into other cells

65
Q

conjugation

A

DNA is transferred from one prokaryote to another using a sex pilus which allows DNA to be transferred in the form of a plasmid

66
Q

facultative anaerobes

A

toggle between aerobic and anaerobic metabolism

67
Q

microaerophiles

A

need oxygen to grow, but high concentrations of it can poison them

68
Q

aerotolerant anaerobes

A

oxygen tolerant: cannot use O2 for metabolism but the presence of oxygen doesn’t harm them

69
Q

thioglycolate broth

A

enriched, differential medium used to determine the oxygen requirements of microorganisms

70
Q

mutualistic

A

both species benefit from the interactions (ex: lichens have a good relationship with algae)

71
Q

commensalism

A

one organism benefits while the other neither benefits nor suffers (ex: birds in trees)

72
Q

parastism

A

parasite benefits while it harms the host

Obligate parasite: cannot reproduce or grow without a host

73
Q

chemotaxis

A

Ability of a bacterial cell to detect chemical stimuli and move toward food or away from toxins

74
Q

negative chemotaxis

A

arises to avoid places with high levels of toxins

75
Q

plasmid

A

Piece of extragenomic DNA that exists and replicates independently from the chromosomal DNA within a cell (circular usually)

76
Q

transposons

A
  • Segments of DNA that can move and allow genes to be transferred to a host organism’s chromosomes, interrupting or modifying the function of a gene
  • Designed to interrupt a gene in such a way that it causes maximal genetic widespread destruction (method is used to identify oncogenes)
77
Q

virus structure

A
  • Have genetic material made of nucleic acids

- Capsid proteins are encoded by the virus genome (RNA/DNA) and encloses the genetic material

78
Q

virus reproduction

A

Must infect a host cell to hijack their reproductive machinery to replicate

79
Q

retroviruses

A

(like HIV) have an RNA genome that must be reverse transcribed into DNA which is then incorporated into the host cell genome

80
Q

generalized virus life cycle

A
  1. Attachment: virus recognizes and binds to a host cell via a receptor molecule on the cell surface
  2. Entry: virus of its genetic material enters the cell
  3. Genome replication & Gene expression: viral genome is copied and its genes are expressed to make viral proteins
  4. Assembly: new viral particles are assembled from the genome copies and viral proteins using the host cell ribosomes
  5. Release: completed viral particles exit the cell and can infect others
81
Q

prions

A

proteins with a defective structure that also trigger other proteins to adopt this faulty structure

82
Q

viroids

A

plant pathogens that consist of a small, circular, ssRNA particle

MCAT (6 decks)

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