BIOLOGY STUDY SUMMARY
Cell Biology, Organisation, Infection & Response & Bioenergetics
What is a cell?
A cell is the smallest unit of life that can replicate independently.
What is the difference between prokaryotic and eukaryotic cells?
Eukaryotic cells are larger and more complex, and include all animal and plant cells. On the other hand,
prokaryotic cells are smaller and simpler (generally unicellular organisms) and do not have nuclei, such
as bacteria.
What organelles are found in plant cells and animal cells?
The organelles that are found in both animal and plant cells are the cell membrane, nucleus, ribosomes,
mitochondria, and cytoplasm.
What organelles do plant cells have that animal cells don't?
Plant cells have a permanent vacuole, chloroplasts, and a cell wall, whereas animal cells do not.
What is the function of the cell membrane?
The function of the cell membrane is to control what enters and leaves the cell via stratified diffusion. It
can do this because it is selectively permeable.
What is the function of the nucleus?
The nucleus stores DNA, and so controls most of the cell's processes.
What are the function of mitochondria?
The function of mitochondria is to produce ATP (energy) via aerobic respiration.
What are the function of ribosomes?
The function of ribosomes is protein synthesis.
What is the function of cytoplasm?
Cytoplasm is the site of chemical reactions (gel-like substance, made from water, sugars, and salts
What is the cell cycle?
The cell cycle is the regular sequence of growth and division that cells undergo.
Why do multicellular organisms need to continually replace cells?
Multicellular organisms need to continually replace cells in order to grow, develop and repair.
, How does a cell divide?
1) In a cell that isn't dividing, the DNA is spread out in long strings.
2) Before the cell divides, it grows, and increases the number of mitochondria and ribosomes.
3) The cell then duplicates its DNA into X-chromosomes.
4) When the cell divides, the DNA lines up in chromosomes in the centre of the cell, and cell fibres
connect to each pole and pull them apart.
5) Then, membranes form around the new sets of chromosomes, forming the nuclei of the new
genetically-identical daughter cells.
6) Finally, the cytoplasm and cell membrane divide.
What are chromosomes?
Chromosomes are coiled up lengths of DNA molecules that are found in the nucleus.
How many chromosomes of each type does a body cell have?
Each body cell has 2 chromosomes (1 from the mother and 1 from the father): these are called diploid
cells, as opposed to haploid (sex cells).
How many pairs of chromosomes do humans have?
Humans have 23 pairs of chromosomes, and thus a total of 46 chromosomes.
What is a micrometer in standard form?
In standard form, a micrometer is 1x10^-6m.
What is a nanometer in standard form?
In standard form, a micrometer is 1x10^-9m.
What is a millimeter in standard form?
In standard form, a millimeter is 1x10^-3m.
What is a centimeter in standard form?
In standard form, a centimeter is 1x10^-2m.
What is the function of the permanent vacuole?
The permanent vacuole is filled with cell sap (a weak solution of sugars, amino acids and salts) to help
keep the cell turgid.
Cell Biology, Organisation, Infection & Response & Bioenergetics
What is a cell?
A cell is the smallest unit of life that can replicate independently.
What is the difference between prokaryotic and eukaryotic cells?
Eukaryotic cells are larger and more complex, and include all animal and plant cells. On the other hand,
prokaryotic cells are smaller and simpler (generally unicellular organisms) and do not have nuclei, such
as bacteria.
What organelles are found in plant cells and animal cells?
The organelles that are found in both animal and plant cells are the cell membrane, nucleus, ribosomes,
mitochondria, and cytoplasm.
What organelles do plant cells have that animal cells don't?
Plant cells have a permanent vacuole, chloroplasts, and a cell wall, whereas animal cells do not.
What is the function of the cell membrane?
The function of the cell membrane is to control what enters and leaves the cell via stratified diffusion. It
can do this because it is selectively permeable.
What is the function of the nucleus?
The nucleus stores DNA, and so controls most of the cell's processes.
What are the function of mitochondria?
The function of mitochondria is to produce ATP (energy) via aerobic respiration.
What are the function of ribosomes?
The function of ribosomes is protein synthesis.
What is the function of cytoplasm?
Cytoplasm is the site of chemical reactions (gel-like substance, made from water, sugars, and salts
What is the cell cycle?
The cell cycle is the regular sequence of growth and division that cells undergo.
Why do multicellular organisms need to continually replace cells?
Multicellular organisms need to continually replace cells in order to grow, develop and repair.
, How does a cell divide?
1) In a cell that isn't dividing, the DNA is spread out in long strings.
2) Before the cell divides, it grows, and increases the number of mitochondria and ribosomes.
3) The cell then duplicates its DNA into X-chromosomes.
4) When the cell divides, the DNA lines up in chromosomes in the centre of the cell, and cell fibres
connect to each pole and pull them apart.
5) Then, membranes form around the new sets of chromosomes, forming the nuclei of the new
genetically-identical daughter cells.
6) Finally, the cytoplasm and cell membrane divide.
What are chromosomes?
Chromosomes are coiled up lengths of DNA molecules that are found in the nucleus.
How many chromosomes of each type does a body cell have?
Each body cell has 2 chromosomes (1 from the mother and 1 from the father): these are called diploid
cells, as opposed to haploid (sex cells).
How many pairs of chromosomes do humans have?
Humans have 23 pairs of chromosomes, and thus a total of 46 chromosomes.
What is a micrometer in standard form?
In standard form, a micrometer is 1x10^-6m.
What is a nanometer in standard form?
In standard form, a micrometer is 1x10^-9m.
What is a millimeter in standard form?
In standard form, a millimeter is 1x10^-3m.
What is a centimeter in standard form?
In standard form, a centimeter is 1x10^-2m.
What is the function of the permanent vacuole?
The permanent vacuole is filled with cell sap (a weak solution of sugars, amino acids and salts) to help
keep the cell turgid.
