Bio p1

• Eukaryotes are animal and plant cells with a nucleus
• Eukaryotic cells contain their genetic material (DNA) enclosed in a nucleus
• In prokaryotic cells, the genetic material (DNA) is not enclosed in a nucleus
• Prokaryotic cells are much smaller than eukaryotic cells
• Prokaryotes contain loops of DNA and plasmids
• Milli means 1/1000th. 1 millimetre is 1/1000th of a meter. 1mm = 1 x 10⁻³ m
• micro means 1/1000000th. 1 micrometer is 1/1000000th of a metre. 1㎛ = 1 x 10⁻⁶ m
• Nano means 1/1000000000th.

  1 nanometre (nm) is 1/1000000000th of a metre 1nm =1 x 10⁻⁹ m
• 1 order of magnitude means 10x.
• The function of the nucleus is to enclose the genetic material
• The cytoplasm is a watery solution where chemical reactions take place.
• The cell membrane controls the molecules that can enter and leave the cell
• Mitochondria and ribosomes are too small to be seen
• Mitochondria are where aerobic respiration takes place
• Ribosomes are the sites of protein synthesis
• Plant cells have a regular shape
• Chloroplasts contain chlorophyll and are the sites of photosynthesis
• The cell wall is made from cellulose. This strengthens the cell.
• The vacuole is filled with a fluid called cell sap. The vacuole helps give the plant cell its shape
• most Animal cells are specialised. They have adaptions which help them to carry out their particular functio.
• When cells become specialised scientists call that differentiation
• The job of a sperm cell is to join with an ovum (Egg cell). We call that process fertilisation
• During fertilisation, the genetic information of the ovum and sperm combine.
• Sperm cells contain half the genetic information of a adult cell.
• Sperm cells have a long tail Which helps them swim to the egg cell. They are also stream line to make this easier
• Sperm is is packed full of mitochondria that provide the energy needed for swimming
• Sperm cells contain enzymes which allow them to digest their way through the outer layer of the ovum
• Nerve cells are specialised to carry electrical impulses around the body.
• The axon carries the electrical impulses from one part of the body to another
• Myelin insulates the axon and speeds up the transmission of nerve impulses
• Synapses are junctions which allow the impulse to pass from one nerve cell to another
• Dendrites increase the surface area so that other nerve cells can connect more easily
• Muscle Cells can contract
• Muscle cells contain protein Fibres which can change their length.
• When a muscle cell contracts, these protein fibres shorten, decreasing the length of the cell.
• Muscle cells are packed full of mitochondria to provide energy for contraction
• Muscle cells work together to form muscle tissue
• Root hair cells increase the surface area of the root so it can absorb water and dissolved minerals more effectively
• Root hair cells do not contain chloroplasts
• Xylem are found in the plant stem. They form long tubes. They carry water and dissolved minerals from the roots to the leaves