genes- genes are long portions of chromosomal DNA generally 10, 000-50, 000 base pairs long that code for specific traits or proteins/groups of proteins

chromosomes- entire chains of DNA with a group of stabilizing proteins, wrapped around a protein called histones to form a bundle. chromosomes generally exist in an unravelled state inside the nucleus and only condense to make transfer during cell replication easier

Movement- all living organisms must be able to move itself/parts of itself as an essential process for capturing food/avoiding predators

respiration- the ability to convert energy from nutrients such as carbs and fats into usable energy for cell processes

sensitivity- ability of living organisms to respond to outside stimulus from their environment

Growth- the ability to increase mass, using extra energy from respiration to contribute to making new cells and therefore growth

reproduction- the ability to asexually or sexually created offspring from an existing organism. important in the survival of the species

nutrition- the requirement for nutrition or food for survival, reproduction and growth processes

plant cells do not change shape before undergoing mitosis, and do not contain centrioles to assist the mitotic spindle, which does not contain asters either.

cytokinesis in animal cells occurs by the formation of a cell plate down the middle of the cell, which consists of plasma membrane and other cell wall parts, separating two daughter cells

cytokinesis occurs in animal cells as contractile cytokinesis, a ring-like filament structure called the contractile ring pinches the cell in two, producing an indentation called the cleavage furrow to produce two new daughter cells

mitotic spindle- a structure composed of microtubules that forms between centrosomes as they move apart to opposite ends of the cell. microtubules can bind to the centromere on chromosomes on the kinetochore- a patch of protein on each side of the centromere. microtubules that don't bind to kinetochores grab onto microtubules from the opposite side to stabilise. more microtubules extends towards the edge of the cell, forming the aster

mitotic spindle captures chromosomes and starts to organise them, nuclear envelope breaks down and releases chromosomes

chromosomes are all captured and aligned at the metaphase plate. the spindle checkpoint occurs, checking all kinetochores are attached to microtubules from opposite poles of the cell

sister chromatids are separated and pulled to opposite poles of the cell, the microtubules not attached to chromosomes elongate, making the cell longer

cell starts to re-establish structures, mitotic spindle breaks down, nucleus and nuclear membrane starts to reform for the two new daughter cells, chromosomes start to de-condense cytokinesis begins

TEM- uses beam of electrons through an object and takes a reading of the electrons. very clear resolution, can magnify up to 500 000 x. images will always be in black and white and 2d, can only use non living specimens

colour, can use dead or alive specimens, lower resolution and limited magnification

SEM- uses a beam of electrons which bounce back and produce a 3d image with texture and shape. high resolution, not as much as TEM. black and white image. non living specimens

the diameter of the viewing area that can be seen under a microscope- find fov in mm, convert to micrometres and divide by estimated object size

1) the enzyme DNA helicase pries apart the two strands from each other like a zipper- a leading strand (5'-3') and a lagging strand (3'-5')

RNA/DNA primase then goes along both strands and creates a starting point for DNA polymerase to go along the strand and attach matching nucleotides to each strand. RNA primase is only needed once on the leading strand as DNA polymerase and the leading strand run in the same direction, meaning it can smoothly go along the strand in one go. However, RNA primase must create several starting points on the lagging strand as it goes in the opposite direction to DNA polymerase, meaning the lagging strand must be synthesized in short burst, creating segments called okazaki fragments

3) another polymerase goes along the strands and replaces all the RNA primase

4) an enzyme called DNA ligase goes along and joins all the okazaki fragments together

joined by hyrdogen bonds- A& T form two bonds, C & G form 3

three components of a nucleotide- phosphate group, pentose sugar, nitrogenous base

stable arrangement- the arrangement of the two strands running in opposite directions to each other (5'-3' and 3'-5')