Do all cells in a multicellular organism retain the ability to divide?
No. Some cells do not retain the ability to divide.
AQA A-Level Biology - (7402) · 3.2.2
Revise AQA A-Level Biology - (7402) specification point 3.2.2, All cells arise from other cells, with free active-recall flashcards. Flip through the set or review every question and answer below.
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Do all cells in a multicellular organism retain the ability to divide?
No. Some cells do not retain the ability to divide.
What are the two main parts of the cell cycle in dividing eukaryotic cells, and what usually follows them?
Interphase and mitosis, usually followed by cytokinesis.
What happens to a cell and its DNA during interphase?
The cell grows and its DNA is replicated.
What is the structure of a replicated chromosome?
Two genetically identical sister chromatids joined at a centromere.
Why are chromosomes not distinct under a light microscope during interphase?
Their DNA is not highly condensed.
What happens during prophase of mitosis?
Chromosomes condense and become visible, the nuclear envelope breaks down, and a spindle forms.
What happens to chromosomes and spindle fibres during metaphase?
Chromosomes align at the cell equator, and spindle fibres attach to their centromeres.
What happens during anaphase of mitosis?
Sister chromatids separate at their centromeres, and spindle fibres move them to opposite poles.
What happens during telophase of mitosis?
Chromosomes reach the poles and decondense, and nuclear envelopes form around the two sets.
What does cytokinesis usually do?
It divides the cytoplasm, producing two daughter cells.
Why does each daughter cell receive the same genetic information as the parent cell after mitosis and cytokinesis?
DNA is replicated before the sister chromatids separate.
Are viruses living or non-living?
Non-living.
Do viruses reproduce by cell division?
No, viruses do not reproduce by cell division.
What happens after viral nucleic acid enters a host cell to produce new virus particles?
The host cell’s machinery uses the viral genetic information to produce viral components, which are assembled into new virus particles.
How do you calculate a cell’s actual size from its image size and magnification?
What is the image size of a cell?
The measured apparent size of the cell in the image.
What does magnification express?
How many times larger the image is than the actual object.
What unit requirement applies when calculating actual size from an image?
Image size and actual size must use consistent units. Units can be converted before or after the calculation.