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Voice Of The Genome Flashcards

(114 cards)

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1
Q

What is the structure of the nucleus

A

Double membrane (nuclear envelope) with pores
Largest organelle

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2
Q

What’s the function of the nucleus

A

Contains genetic material

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3
Q

What’s the structure of the nucleolus

A

Darker staining region if the nucleus

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4
Q

What’s the function of the nucleolus

A

Region where RNA used to make ribosomes is transcribed

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5
Q

What’s the structure of the ribosome

A

2 subunits (large & small)
Made from ribosomal RNA and protein
Free in cytoplasm or in RER
80s in eukaryotes

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6
Q

What’s the function if the ribosome

A

Protein synthesis

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7
Q

What’s the structure of the rough endoplasmic reticulum

A

interconnected membrane-blind flattened sacks
Continues from nucleus
Ribosomes attached (rough)

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8
Q

What’s the function of the RER

A

Protein folding and transport within cell
(Lots found in cells secreting proteins)

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9
Q

What’s the structure of the Golgi apparatus

A

Stacks of flattened membrane-bound sacks of decreasing size

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10
Q

What’s the same of the membrane bound flattened sacks of the Golgi and ER

A

Cisternae

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11
Q

How are the cisternae of the Golgi formed?

A

Fusion of vesicles from endoplasmic reticulum

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12
Q

What are the different vesicles in the Golgi

A

Transport vesicle- comes from ER
Secretory vesicle- leave Golgi

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13
Q

What’s the fiction of the Golgi apparatus?

A

Protein modification

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14
Q

What’s the structure of the smooth endoplasmic reticulum?

A

Same as RER
No ribosomes

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15
Q

What’s the function of the sER

A

Lipid synthesis and transport

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16
Q

Where are high amounts of sER found?

A

Liver and testes

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17
Q

What’s the structure of the mitochondria

A

Rod-like structures
Double membrane- inner one folded (cristae)

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18
Q

What’s the function of the mitochondria

A

Aerobic respiration

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19
Q

What does the number of mitochondria depend on?

A

Energy demand of cell

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20
Q

What’s the structure of a lysosome

A

Spherical sacs contains digestive enzymes
Single membrane

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21
Q

What’s the function of lysosomes

A

Enzymes within break down unwanted substances
Whole cell destruction

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22
Q

What’s the structure of the centrioles

A

Hollow microtubules of proteins at right angles to each other
1 pair in each cell

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23
Q

What’s the function of the centrioles

A

Makes spindle fibres for mitosis

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24
Q

What’s a prokaryotic cell

A

Cell with no membrane bound organelles (nucleus, Golgi, ER, lysosomes, mitochondria)

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25
What are the organelles in all bacteria cell
Cell wall Cell membrane Circular DNA 70s Ribosomes Cytoplasm
26
What other organelles may be in bacteria cells
Flagellum Plasmids (DNA) Mesosome Pili Slime capsule
27
What type of DNA is in the circular DNA
Double stranded
28
What’s the function of the slime capsule
Prevent dehydration Prevent recognition by antibodies
29
What’s a mesosome
I folding of the cell membrane
30
What are pili
Thin tubes of proteins Attach to cells
31
What are the destinations for proteins
Cytoplasm Lysosomes Cell membrane Extracellular (outside cell)
32
What’s the first step of protein transport
Protein made in ribosome on RER
33
What’s the second step of protein transport
Protein folded into specific 3D shape inside RER
34
What’s the third step of protein transport
Proteins leave RER is a vesicle you travel to Golgi
35
What’s the fourth step of protein transport
Transport vesicles fuse together forming flattened sacks of Golgi
36
What’s the fifth step of protein transport
Proteins modified in Golgi (eg polysaccharide added)
37
What’s the sixth step of protein transport
Golgi produces secretory vesicle that fuse with plasma membrane (by exocytosis) releasing proteins
38
What are the components of an egg cell
Follicle cells Zona pellucida Haploid nucleus Cytoplasm Cell membrane
39
What’s the function of the follicle cells
From ovaries Release chemicals attracting sperm cells- aids fertilisation
40
What’s the function of the zona pellucida
Jelly like coating Protects egg Thickens after fertilisation- prevents polyspermy
41
What’s the zona pellucida made from
Glycoproteins from egg cell
42
What’s specific about the cytoplasm in an egg cell
Contains lots of nutrients (eg lipid droplets)- provides raw materials/ energy for growth and development
43
What’s specific about the lysosomes in egg cells
Contain enzymes that thicken zona pellucida (cortical granules)
44
What’s different about the nuclei in gametes
Haploid nucleus (1 copy of each chromosome) so full set is restored after fertilisation
45
What are the parts of a sperm cell
Flagellum Mid piece Haploid nucleus Acrosome
46
What’s the function of the flagellum in a sperm cell
Help movement (different structure to flagella of bacteria)
47
What’s the adaptation of the mid piece
Contain lots of mitochondria to provide energy
48
What’s the function of the Acrosome
Specialised lysosome contains digestive enzymes that break down the follicle cells during fertilisation
49
First step of fertilisation
chemicals from follicle cells attract sperm cells triggers acrosome reaction
50
second step of fertilisation
enzymes from acrosome digest follicle cells and zona pellucida
51
third step of fertilisation
sperm cell membrane fuses with egg cell membrane triggers cortical reaction
52
fourth step of fertilisation
sperm cell nucleus enters egg cell and fuses with egg cell nucleus diploid nucleus formed
53
what's the acrosome reaction
acrosome swells acrosome membrane fuses with sperm plasma membrane digestive enzymes released by exocytosis
54
what's the cortical reaction?
cortical granules fuse with egg cell membrane enzymes released by exocytosis into zona pellucida enzymes cause it to harden
55
what does the cortical reaction do
prevent polyspermy
56
how does meiosis create genetic variation
by creating different combinations of alleles in gametes
57
what 2 ways can meiosis create genetic variation
independent assortment crossing over
58
what happens in the first division in meiosis
homologous chromosomes separate
59
what happens in the second division in meiosis
sister chromatids separate
60
how does independent assortment create genetic variation
homologous chromosomes line up randomly making different combinations of maternal and paternal chromosomes
61
how does crossing over create genetic variation
DNA exchanged between non-sister chromatids making new combinations of alleles
62
what's the chiasma
point of crossing over
63
when does crossing over happen
between DNA replication and 1st division
64
what is sex linkage
inheritance of a gene on X/Y chromosome is linked to biological sex
65
what's autosomal linkage
inheritance of genes on different chromosomes are independent to each other
66
what does the distance between 2 genes impact
closer together = stronger linkage less space for chiasma to form
67
what do stem cells do
give rise to daughter cells that specialise
68
define totipotent
stemm cell can give rise to any cell (zygote/ morula)
69
define pluripotent
can give rise to most types of cell (embryonic stem cell)
70
define multipotent
can give rise to several cell types (hematopoietic)
71
define unipotent
give rise to 1 cell type
72
define exon
part of DNA the produces proteins (coding region)
73
define intron
non-coding region removed from mRNA before translation
74
define promoter
site RNA polymerase binds to
75
define operon
all parts of a gene
76
role of repressors
binds to operator preventing transcription = no protein
77
what does the presence of lactose do for the repressor
repressor removed from binding to DNA inactivating it
78
what does inactivating a repressor cause
RNA free to transcribe gene producing mRNA
79
describe differential gene expression
specialisation reached by turning genes on/off gene turned on= activated active mRNA produced in nucleus producing specific protein protein combo controls cell structure & function
80
describe heterochromatin
compact (more dense) methylate unmodified histones (unacetylated) deactivated genes
81
describe euchromatin
less dense not methylated activated genes modified histones (acetylated)
82
define methylation
methyl group attaches to a C base in DNA
83
why does methylation cause heterochromatin
methyl groups exclude water
84
define modification
acetyl groups added to histones which repel each other causes euchromatin
85
describe the experiment that proved specialisation
mRNA extracted from different stages of frog development reverse transcriptase added to later stage making DNA tube of mRNA and DNA mixed
86
how did this show specialisation
mRNA in 1st stage will bind to complimentary DNA of 2nd stage free DNA= only in 2nd stage free RNA= only in 1st stage
87
describe FOP
genetic condition when WBCs produce protein activating muscle cells changing them to bone
88
Where does hair get its melanin from
The roots
89
How does UV affect hair
As hair grows UV hits it destroying the melanin around the nuclei As melanin comes from roots it’s not restored so hair becomes lighter
90
91
What enzyme makes melanin
Tyrosinase
92
Why do Siamese cats exist
Have mutant allele for tyrosinase/ temperature sensitive Cold body part= active enzyme -> dark Warm body part= inactive enzyme -> light
93
94
why is mitosis important
enables growth and repair asexual reproduction (eg: in fungi)
95
what is another term for a pair of centrioles
centrosome
96
define kinetochare
protein complex at centromere that spindle fibres attach to
97
what happens in interphase
chromosomes unravel (single mass) nucleolus and nuclear envelope visible centrioles together
98
what happens in prophase
chromosomes condense (visible) nuclear envelope breaks down nucleolus disappears centrioles move to opposite poles and start forming spindle fibres
99
what happens in metphase
chromosomes line up at cell equator spindle fibres attach to chromosomes at centromere
100
what happens in anaphase
centromere splits separating sister chromatids spindle fibres shorten pulling chromosomes to opposite poles of the cell
101
what happens in telophase
nuclear envelope reforms chromosomes decondense (not visible) spindle fibres break down
102
what happens in cytokinesis
fibre ring of actin )protein) contracts pinching cell into 2 daughter cells
103
define polygenic inheritance
characteristic controlled by multiple genes 9eg: skin colour)
104
How does the no. genes affect possible phenotypes
more genes= more possible phenotypes
105
mitotic index formula
mitotic index = no. cells in mitosis / total no. cells in field view
106
define assimilation
amount of energy from genes towards tissue growth
107
1st step of melanin production
stimuli increases MSH levels (melanin stimulating hormone)
108
2nd step of melanin production
MSH bind to receptors on melanocytes
109
3rd step of melanin production
melanocytes produce melanin
110
4th step of melanin production
melanin put into melanosomes and transported to skin cells releasing melanin (exocytosis)
111
5th step of melanin production
melanin surround nucleus preventing damage from UV (sacrificial chemical)
112
113
Define epigenetics
Heritable change in gene function without change to the DNA base sequence
114

AS Biology (4 decks)

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