Edexcel: Additional Sciences - Biology: Topic 1 (The building blocks of cells)

True or false: The Nucleus is an organelle that contains DNA.

True or False: The Mitochondria are organelles in which respiration occurs.

True or False: In light microscopes, light passes through a specimen and then through magnifying lenses so you see the object much bigger than it really is.

The [blank_start]cell membrane[blank_end] separates the contents of the cell and its surroundings. It controls the movement of substances like [blank_start]oxygen[blank_end], [blank_start]glucose[blank_end] and [blank_start]carbon dioxide[blank_end].

Plant and animal cells have some features in common.. These are?

In the [blank_start]1930's[blank_end] the [blank_start]electron microscope[blank_end] was invented. This uses a [blank_start]beam of electrons[blank_end] to magnify speciments up to about [blank_start]2,000,000[blank_end] times. This would make an average person 3333km tall.

Electron microscopes show us that bacterial cells contain two types of DNA. [blank_start]Chromosomal DNA[blank_end] is a [blank_start]giant loop[blank_end] of DNA [blank_start]containing most[blank_end] of the genetic material. It is not neatly packaged like plant or human chromosomes. [blank_start]Plasmid DNA[blank_end] comes in small loops and [blank_start]carries extra[blank_end] information

Label the parts of a bacterial cell.

The Chromosomes in the nuclei of your cells contain your genetic information. They are made of a chemical called [BLANK]. What is it?

One Gene contains the instructions for [blank_start]One protein[blank_end]. Often [blank_start]several genes work together[blank_end] to produce what is needed for a single feature. For example, your [blank_start]eye colour[blank_end] is the result of proteins made by several different genes. So is the size and shape of your [blank_start]nose[blank_end], and so many other features of your body. Some Genes also carry the instructions for the proteins that control the chemical processes in your body.