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.