Cell structure and Organisation Eduqas A Level Biology
What's the structure of the nucleus?
Nucleolus in the centre, then nucleoplasm, then 2 membranes. Inner membrane is the nuclear envelope which has pores, and the outer is continuous with endoplasmic reticulum.
What is the function of the nucleolus?
The site of formation of rRNA
How do large molecules go out of the nucleus?
Via the nuclear pores
Define tissue
a group of similar cells that perform a common function
Define organ
a structure made up of a group of tissues, working together to perform specific functions
What is skeletal muscle?
also called striated muscle, it is attached to the skeleton by tendons; contraction of skeletal muscle is under voluntary control
Define organ system
group of organs that work together to perform a specific function
What's the term given to viruses that attack bacteria?
Bacteriophages
What is the nucleoplasm?
Chromatin
What happens to chromatin during mitosis?
Chromatin condenses into chromosomes
What's the function of nucleus?
Contains chromosomes which are needed for transcription and protein synthesis.
What is smooth muscle?
Found in the walls of all the hollow organs of the body except the heart. It condtraction reduces the size of these structures; movement generally is considered Involunatry
Describe structure of a virus
Has a nucleic acid in the core, surrounded by a protein coat called the capsid.
Describe the structure of mitochondria
Inner matrix with folds that are called cristae, and have an outer membrane and inner membrane.
How are mitochondria adapted to their function?
Matrix increases surface area for attachment of enzymes.
What is cardiac muscle?
Moves rhythmically and never tires, found in the heart.