Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MCAT > Biology > Flashcards

Biology Flashcards

(80 cards)

Start Studying
1
Q

Do prokaryotic cells contain a nucleus?

A

NO!!!

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

Membrane-bound Organelles found in eukaryotic, prokaryotic, or both?

A

ONLY EUKARYOTES

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

The nucleolus is…

A

A subsection of the nucleus where ribosomal RNA (rRNA) is synthesized!!

rRNA – RNA component of ribosomes

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

Cytoplasmic/Extranuclear Inheritance

A

the transmission of genetic material independent of the nucleus

MITOCHONDRION – contain own genes and replicate independently of the nucleus through binary fission

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

Apoptosis

A

MITOCHONDRION

release enzymes from the ETC kickstarts apoptosis

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

Difference between rough ER and smooth ER?

A

Rough ER studded with ribosomes and translated proteins.

Smooth ER used for lipid synthesis and detoxification. Also transports proteins from RER to Golgi.

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

Primary function of a peroxisome?

A

breakdown of very long chain fatty acids via beta oxidation

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

Microfilaments

A

Component of the cytoskeleton. Solid polymerized rods of actin. RESISTANT TO COMPRESSION OR FRACTURE. Interact with myosin to generate movement.

Role in CYTOKINESIS (division of material between daughter cells). Creates cleavage furrow between two daughter cells (ring of actin filaments).

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

Microtubules

A

Component of cytoskeleton. Hollow polymers of tubulin. Pathway for KINESIN and DYNEIN.

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

What is the 9+2 structure?

A

Pertaining to the structure of cilia and flagella. Composed of nine pairs of microtubules forming an outer ring with two microtubules in the middle.

ONLY IN EUKARYOTES

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

Centrioles

A

Found in the CENTRISOME. Organize the mitotic spindle on opposite ends of cell. Microtubules emanate from centriole and attach to chromosome via the KINETOCHORE.

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

Parenchyma

A

The functional parts of an organ. Comprised of EPITHELIAL cells in many organs. Attached via basement membrane.

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

Stroma

A

The support structure of an organ for the endothelial cells. Comprised primarily of CONNECTIVE TISSUE.

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

Nucleoid Region

A

Found in PROKARYOTES.
Region where the single circular molecule of DNA is found.

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

Obligate Aerobe

A

bacteria that require oxygen for metabolism

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

Obligate Anaerobes

A

bacteria that cannot survive in an oxygen-containing environment

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

Facultative Anaerobe

A

bacteria that can toggle between aerobic and anaerobic respiration depending on what’s available

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

Describe the membrane/outside of a prokaryote.

A

CELL WALL outer barrier of the cell
CELL/PLASMA MEMBRANE

these together are known as the ENVELOPE of the prokaryote

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

Gram-positive vs gram-negative prokaryotic cell walls.

A

Gram-Positive: thick layer of peptidoglycan (PURPLE) and lipoteichoic acid

Gram-Negative: very thin layer of peptidoglycan separated by periplasmic space (PINK) and lipopolysaccharides

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

Plasmids

A

carry DNA in prokaryotes NOT NECESSARY for survival

NOT part of the genome

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

ETC in prokaryotes.

A

They lack mitochondrion

Instead, use the cell membrane for the ETC.

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

Ribosomal difference between eukaryotes and prokaryotes.

A

Prokaryote: 30S and 50S (SMALLER)
Eukaryotes: 40S and 60S (LARGER)

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

A subset of plasmids capable of integrating into the genome of a bacteria cell?

A

Episome

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

Transformation

A

integration of foreign genetic material into the host genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Conjugation
Sexual reproduction in bacteria. Unidirectional via a conjugation bridge.
26
How is a Hfr (high frequency of recombination) bacterium formed?
The sex factor is integrated into a bacterium genome. The conjugation bridge breaks before the entire copy of the genome is transferred to the recipient. This bacterium is now Hfr.
27
Transduction
only genetic recombination process that requires a vector -- virus carries material from one to another. BACTERIOPHAGE
28
Transposon
genetic elements capable of inserting and removing themselves from the genome
29
Growth Phases of a Bacterial Colony
1. Lag Phase 2. Exponential (Log) Phase 3. Stationary Phase 4. Death Phase via binary fission
30
Capsid
Protein coat of a virus which may be surrounded by an envelope composed of phospholipids
31
Enveloped Virus
EASIER TO KILL (prone to heat, detergents, and desiccation)
32
Virion
the viral progeny produced in an infected host cell
33
Negative-sense RNA viruses
MUST carry with them an RNA replicase in the virion to ensure complementary RNA strand is synthesized
34
Retrovirus
ENVELOPED SINGLE-STRANDED RNA carry the enzyme reverse transcriptase (synthesizes DNA from the RNA) -- this then integrates into the host genome
35
Enzyme responsible for creating complementary RNA (+) from a negative sense RNA virus.
RNA replicase
36
Lytic Cycle
bacteriophage maximizes the use of the cell's machinery without regard for life busts out the hoe like a bomb very virulent
37
Lysogenic Cycle
integration into the host genome or acts as a prophage (exits the cell but keeps it intact) acts as a sneaky bastard and gets replicated superinfection
38
Prions
infectius proteins due to triggering the misfolding of other proteins usually through conversion of alpha helix to a beta-pleated sheet
39
Cytokinesis
the cytoplasmic division in eukaryotes at the end of mitosis (cell separation) invagination of the cell membrane
40
How many chromosomes do humans have?
46 total (autosomal cells // two copies of each chromosome) [diploid] 23 from each parent (germline cells // haploid)
41
Which stages of the cell cycle make up interphase? What is interphase?
G1, S, and G2 longest part of the cell cycle
42
What stage of the cell cycle are cells that don't divide in?
An off shoot of G1 called the G0 stage.
43
What form are chromosomes in during interphase?
less condensed version called CHROMATIN must be available to RNA polymerase
44
G1 Stage of the Cell Cycle
Presynthetic Gap cells create organelles passage to the S stage is governed by a restriction point
45
S Phase of the Cell Cycle
Synthesis of DNA cell replicates its genetic material chromatids bound together at the centromere 46 chromosomes with 92 chromatids (2x DNA than G1 cells) organized into 23 homologous pairs
46
G2 Stage of Cell Cycle
Postsynthetic Gap quality control checkpoint for DNA replication before cell divides
47
M Stage of the Cell Cycle
NOT Interphase Mitosis mitosis and cytokinesis
48
G1/S and G2/M checkpoints in the cell cycle regulated by what?
p53 main protein responsible to check if the condition of the DNA is good enough for synthesis
49
What is one of the most common mutations found in cancer?
mutation of the gene TP53 the gene that produces the p53 protein
50
Prophase (Mitosis)
chromosomes condense and spindle forms centrosomes -- microtubule organizing center -- migrate to ends of cell kinetochores
51
Metaphase (Mitosis)
chromosomes align at the metaphase plate (equatorial plate)
52
Anaphase (Mitosis)
sister chromatids separate kinetochore fibers shorten
53
Telophase (Mitosis)
new nuclear membranes form cytokinesis
53
Telophase (Mitosis)
new nuclear membranes form cytokinesis
54
Meiosis I vs Meiosis II
Meiosis I results in homologous chromosomes separating (haploid daughter cells) (reductional division) Meiosis II results in the separation of sister chromatids without a change in ploidy (equatorial division // more similar to mitosis)
55
Mitochondrial DNA
CIRCULAR and SELF-REPLICATING
56
Which organelles are surrounded by a single membrane and which are surrounded by a double membrane?
SINGLE: lysosome DOUBLE: mitochondrion and nuclei
57
A virus needs to be transported into the nucleus in order to synthesis viral proteins. What is the genomic content of the virus?
DNA virus!!! only DNA virus need host nuclear RNA polymerase
58
Crossing Over
during Prophase I of meiosis, homologous chromosomes come together in a process called synapsis each synaptic pair contains four chromatids called a tetrad; these break at the chiasma DNA is exchanged via crossing over NOTE: this happens between HOMOLOGOUS CHROMOSOMES and not between sister chromatids
59
Linked Genes and recombination via crossing over
Linkage refers to the tendency of genes to be inherited together genes that are farther away are less likely to be linked and more likely to undergo crossing over relative to each other
60
Ploidy through Mitosis vs Meiosis note: n = 23
Mitosis: 2n --> 2x 2n Meiosis: 2n --> 2x n (Meiosis I; split homologous pairs) --> 4x n (Meiosis II)
61
What is the SRY gene?
The SRY (sex-determining region Y) is a gene on the Y chromosome which encodes for transcription factors that initiates testis differentiation
62
Sertoli cells
essential for spermatogenesis nourish the formed sperm cells in the seminiferous tubules
63
Leydig cells
secrete testosterone and other androgens
64
Acrosome
cap on the head of a sperm derived from the golgi apparatus and is necessary to penetrate the ovum
65
Primary Oocytes
the oogonia that have already undergone DNA replication at birth 2n cells arrested in Prophase I after menarche, one will complete meiosis I each month and produce a secondary oocyte (n) and polar body
66
Secondary Oocyte
arrested in Metaphase II (n) will only complete the remainder of meiosis II if fertilized by a sperm cell
67
Describe hormonal control prior to and during puberty in a female/
Before puberty: the hypothalamus restricts the production of GnRH (gonadotrophin-releasing hormone) Puberty: hypothalamus produces GnRH, which triggers the anterior pituitary gland to release FSH (follicle-stimulating hormone) and LH (luteinizing hormone)
68
Hormonal control of male sexual development
FSH stimulates Sertoli cells and triggers sperm maturation and LH causes the interstitial cells to produce testosterone testosterone results in the development of secondary sex characteristics
69
Hormones and the menstrual cycle
Estrogen is secreted in response to FSH and results in the development and maintenance of the female reproductive system; leads to thickening of the endometrium Progesterone is secreted by the corpus luteum (remains of ovarian follicle after ovulation) in response to LH; development and maintenance of the endometrium
70
Follicular Phase of Menstrual Cycle
begins with the menstrual flow GnRH increases due to estrogen and progesterone drop off; this leads to increased FSH and LH these develop ovarian follicles which begin to produce estrogen and negative feedback inhibit GnRH, FSH, and LH
71
Ovulatory Phase of the Menstrual Cycle
Estrogen reaches a point where it positive feedback on GnRH, FSH, and LH the spike in LH induces ovulation
72
Luteal Phase of Menstrual Cycle
LH causes follicle to form corpus luteum which secretes progesterone progesterone and estrogen both high and inhibit GnRH, LH, and FSH
73
Blastulation
First phase of development solid mass of cells called a morula and then the blastula which implants in the endometrium
74
Gastrulation
occurs after blastulation generation of three distinct cell layers archenteron (membrane invagination) and blastopore (opening of archenteron...turns into anus)
75
Primary Germ Layers
Ectoderm - outermost; integument and nervous system Mesoderm - middle layer; muscular and connective tissue, circulatory Endoderm - epithelial lining of digestive and respiratory
76
Neurulation
development of the nervous system notochord (mesoderm) induces neural folds (ectoderm) and neural crest cells
77
Neurulation
development of the nervous system notochord (mesoderm) induces neural folds (ectoderm) and neural crest cells
78
Kinesin vs Dynein direction
Kinesin = ANTEROGRADE movement on microtubule Dynein = RETROGRADE movement on microtubule
79
What is the role of fallopian cilia?
they PROPEL the fertilized oocyte forward into the uterus for proper implantation

MCAT (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions