Biology Paper 1 Notes
Key concepts:
1.1 Explain how the sub-cellular structures of eukaryotic and prokaryotic cells are related to their functions,
including:
Animals and plants are formed from cells. The parts in a cell have particular functions in a cell.
Cells with a nucleus and membrane-bound organelles such as mitochondria are called eukaryotic cells. Cells without a
nucleus are called prokaryotic cells.
An animal cells – nucleus, cell membrane, mitochondria, and ribosomes
Animal cells are eukaryotic as they have nuclei.
They include the nucleus, cell membrane, mitochondria, ribosomes, and cytoplasm. Nucleus: A large structure that
contains genes. Controls the activities of the cell.
Cell membrane: Controls what enters and leaves the cell e.g., oxygen, carbon dioxide and glucose.
Mitochondria: (single: mitochondrion), tiny structures where respiration takes place. It releases energy for the cell
processes.
Ribosomes: Found in the cytoplasm. Where the proteins are made, called protein synthesis.
Cytoplasm: Jelly like substance that fills the cell. Where many reactions take place.
B plant cells – nucleus, cell membrane, cell wall, chloroplasts, mitochondria, vacuole, and ribosomes
Plant cells are eukaryotic as they also include a nucleus.
They include the nucleus, cell membrane, mitochondria, ribosomes, cell wall, chloroplast, and a vacuole.
The parts in a plant cell that are the same in the animal cell have the same functions but only include a few more
structures such as the cell wall chloroplast and the vacuole.
Cell wall: provides the cell with structural protection and support e.g., to help keep its shape.
Chloroplast: part of the cell where photosynthesis takes place to make food for the plant cell.
Vacuole: The large central vacuole contains the cell sap, which helps to keep the plant cell rigid.
C bacteria – chromosomal DNA, plasmid DNA, cell membrane, ribosomes, and flagella
Bacteria is a specialized cell. It has a different kind of cell structure from plant and animal cells.
They are prokaryotic as they do not have a nucleus.
They include chromosomal DNA, plasmid DNA, cell membrane, ribosomes, and flagella.
Chromosomal DNA: A single loop of chromosomal DNA lies free in the cytoplasm. Where most of the bacterial genes are
carried.
Plasmid DNA: Plasmid DNA contains additional genes that are not found in the chromosomes.
Flagella: a tail-like structure that helps the cell move.
1.2 Describe how specialised cells are adapted to their function, including:
Specialised cells are cells that are specialised for different functions. Bacteria cells are a type of specialised cell.
A sperm cells – acrosome, haploid nucleus, mitochondria, and tail
A sperm cell is a sex cell and also a specialised cell.
Acrosome: Helps the sperm cell penetrate into the egg cell.
Haploid nucleus. Contains genetic material for fertilisation.
Tail: Heps the cell swim towards the egg cell.
b egg cells – nutrients in the cytoplasm, haploid nucleus, and changes in the cell membrane after fertilisation
Cytoplasm including nutrients: Supplies nutrients to help the egg survive.
Change in cell membrane after fertilisation: The cell membrane hardens after a sperm cell has entered to allow no more
sperm cells to enter.
Key concepts:
1.1 Explain how the sub-cellular structures of eukaryotic and prokaryotic cells are related to their functions,
including:
Animals and plants are formed from cells. The parts in a cell have particular functions in a cell.
Cells with a nucleus and membrane-bound organelles such as mitochondria are called eukaryotic cells. Cells without a
nucleus are called prokaryotic cells.
An animal cells – nucleus, cell membrane, mitochondria, and ribosomes
Animal cells are eukaryotic as they have nuclei.
They include the nucleus, cell membrane, mitochondria, ribosomes, and cytoplasm. Nucleus: A large structure that
contains genes. Controls the activities of the cell.
Cell membrane: Controls what enters and leaves the cell e.g., oxygen, carbon dioxide and glucose.
Mitochondria: (single: mitochondrion), tiny structures where respiration takes place. It releases energy for the cell
processes.
Ribosomes: Found in the cytoplasm. Where the proteins are made, called protein synthesis.
Cytoplasm: Jelly like substance that fills the cell. Where many reactions take place.
B plant cells – nucleus, cell membrane, cell wall, chloroplasts, mitochondria, vacuole, and ribosomes
Plant cells are eukaryotic as they also include a nucleus.
They include the nucleus, cell membrane, mitochondria, ribosomes, cell wall, chloroplast, and a vacuole.
The parts in a plant cell that are the same in the animal cell have the same functions but only include a few more
structures such as the cell wall chloroplast and the vacuole.
Cell wall: provides the cell with structural protection and support e.g., to help keep its shape.
Chloroplast: part of the cell where photosynthesis takes place to make food for the plant cell.
Vacuole: The large central vacuole contains the cell sap, which helps to keep the plant cell rigid.
C bacteria – chromosomal DNA, plasmid DNA, cell membrane, ribosomes, and flagella
Bacteria is a specialized cell. It has a different kind of cell structure from plant and animal cells.
They are prokaryotic as they do not have a nucleus.
They include chromosomal DNA, plasmid DNA, cell membrane, ribosomes, and flagella.
Chromosomal DNA: A single loop of chromosomal DNA lies free in the cytoplasm. Where most of the bacterial genes are
carried.
Plasmid DNA: Plasmid DNA contains additional genes that are not found in the chromosomes.
Flagella: a tail-like structure that helps the cell move.
1.2 Describe how specialised cells are adapted to their function, including:
Specialised cells are cells that are specialised for different functions. Bacteria cells are a type of specialised cell.
A sperm cells – acrosome, haploid nucleus, mitochondria, and tail
A sperm cell is a sex cell and also a specialised cell.
Acrosome: Helps the sperm cell penetrate into the egg cell.
Haploid nucleus. Contains genetic material for fertilisation.
Tail: Heps the cell swim towards the egg cell.
b egg cells – nutrients in the cytoplasm, haploid nucleus, and changes in the cell membrane after fertilisation
Cytoplasm including nutrients: Supplies nutrients to help the egg survive.
Change in cell membrane after fertilisation: The cell membrane hardens after a sperm cell has entered to allow no more
sperm cells to enter.
