Biology🌱 Flashcards
Animal Cells
Cytoplasm Nucleus Ribosomes Mitochondria Cell membrane
Plant Cells
Cytoplasm Nucleus Ribosomes Vacuole Mitochondria Cell membrane Cell wall Chloroplast
Use of Cell Membrane
Semi-permeable structure that allows some substances to pass through but not all. Therefore it controls movement of substances in and out of the cell.
Use of Cytoplasm
A jelly-like material that contains dissolved nutrients and salts. This is where chemical reactions occur.
Use of Nucleus
Contains genetic material, including DNA and controls cell activities.
Use of Mitochondria
Contains enzymes for respiration and is where most energy is released for respiration.
Use of Cell Wall
Made for cellulose fibres and strengths and supports the cell.
Use of Chloroplast
Contains chlorophyll (green pigment) which absorbs light energy for photosynthesis. Contains enzymes needed for photosynthesis.
Use of Vacuole
Filled with cell sap to help keep the cell turgid.
Prokaryotic Cells
A cell without a nucleus e.g. bacteria and archaea.
Use of Chromosomal DNA
The DNA of bacterial cells is found loose in cytoplasm.
 Use of Plasmid DNA
Small, closed-circles of DNA present in the cytoplasm. Unlike chromosomal DNA, plasmid DNA can move from one bacterium to another giving variation.
Levels of Organisation
Subatomic particles, atoms, molecules, organelles, cells, tissues, organs, organ systems, organisms and biosphere (figure).
Process of Diffusion
Movement of a substance from a high concentration to a low concentration.
Process of Osmosis
Movement of water through a semi-permeable membrane from a high concentration to a low concentration.
Process of Active Transport
Requires energy to move substances from a low concentration to a high concentration. It goes against the concentration gradient.
Mitosis Conditions
2 daughter cells 1 stage cell division Diploid (46 chromosomes) Genetically identical Body cells (not eggs or sperm) Prophase is shorter
What does Uncontrolled cell growth lead to?
Cancer
Meiosis Conditions
4 daughter cells 2 stage cell division Genetically different Only occurs in animals, plants and fungi Creates germ cells (eggs and sperm) Haploid (23 Chromosomes) Prophase is longer
Asexual Reproduction Conditions
One parent
Offspring are genetically identical
Sexual Reproduction Conditions
2 Parent cells
Offspring are genetically different leading to variation
XX Chromosomes
Females
XY Chromosomes
Males
Gene Definition
Small section of DNA on a chromosome that codes for a particular sequence of amino acid, to make a certain protein.