Questão 1
Questão
(Choose all correct.)
The nucleus:
Responda
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is the most prominent organelle.
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has a diameter of 5-10 micrometres.
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is present in almost all cells.
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contains all of the cell's genetic information
Questão 2
Questão
The membrane of the nucleus is the:
Responda
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nucleomembrane
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nuclear membrane
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nuclear envelope
Questão 3
Questão
Choose the incorrect statement about the nucleus.
Responda
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It has four layers of phospholipids.
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It has complex protein structures called pores.
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Its inner surface is lined nuclear lamina, which is made of intermediate filaments.
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Fluid within the lumen of the nucleus maintains its spherical shape.
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Intermediate filaments aid in organising and packing chromatin.
Questão 4
Questão
What is the consequence of a dysfunctional nuclear lamina? (Choose all correct.)
Responda
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Abnormally shaped nuclei
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Progeria syndrome
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Cystic fibrosis
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Cerebral palsy
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Poor mitogenesis/meiosis
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Accelerated ageing
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Slow development
Questão 5
Questão
Choose the incorrect statement about the nuclear pores.
Responda
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They allow mRNA, rRNA, and tRNA to exit.
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It allows control signals into the nucleus.
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It mediates passage into and out of the nucleus.
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Energy and cellular materials move out of the nucleus.
Questão 6
Questão
How much DNA is in the human nucleus?
Questão 7
Questão
DNA is packed in the nucleus so that it is inaccessible until replication.
Questão 8
Questão
The DNA double helix is about [blank_start]2[blank_end]nm in diameter. Bundled into [blank_start]nucleosomes[blank_end] or "beads" using [blank_start]H2a, H2b, H3, and H4[blank_end] histone proteins, it is about [blank_start]10[blank_end]nm in diameter. Further interaction with [blank_start]H1[blank_end] histone proteins [blank_start]coils[blank_end] this into a [blank_start]30[blank_end]nm fibre. During replication this can be [blank_start]looped[blank_end] to form a [blank_start]300[blank_end]nm diameter [blank_start]chromosome[blank_end].
Responda
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2
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nucleosomes
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H2a, H2b, H3, and H4
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10
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H1
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30
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looped
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coils
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300
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metaphase chromosome
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interphase chromosome
Questão 9
Questão
Which kind of chromatin is the denser, inactive form?
Responda
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heterochromatin
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euchromatin
Questão 10
Questão
The ratio of heterochromatin and euchromatin stays static during a cell's lifetime.
Questão 11
Questão
The location of chromosomes in the nucleus is not random.