Biology-Cell hierarchy/structure Flashcards
To revise cell hierarchy /structure and how it works (9 cards)
Define
Cell
A mass of cytoplasm that is bound externally by a cell membrane
Usually microscopic in size, cells are the smallest units of our body
Most cells have one or more nuclei and other organelles that carry out a variety of tasks within the body
Define
Organnelle
A subcellular structure that has one or more specific jobs to perform in the cell, much like an organ does in the body.
The most important cell organelle is the nuclei which store genetic info
Among the more important cell organelles are the mitochondria, which produce chemical energy and ribosomes, which assemble proteins.
Define
Ribosomes
The cellular machinery responsible for making proteins.
There are many ribosomes in each cell, each made up of two subunits.
These two subunits lock around the messenger RNA and then travel along the length of the messenger RNA molecule reading each three-letter codon.
Define
Nulcleus
The structure in a cell that contains the chromosomes.
The nucleus has a membrane around it, and is where RNA is made
Define
RNA
A nucleic acid present in all living cells that has structural similarities to DNA.
Unlike DNA, however, RNA is most often single-stranded.
An RNA molecule has a backbone made of alternating phosphate groups and the sugar ribose, rather than the deoxyribose found in DNA.
Define
Tissue
An aggregate of cells in an organism that have similar structure and function.
Define
Organ
A collection of tissues that structurally form a functional unit specialized to perform a particular function.
Define
Organ system
A biological system consisting of a group of organs that work together to perform one or more functions.
Each organ has a specialized role in making the system run
As well as this, organ system often have distinct tissue types
Define
Organism
a living thing that has an organized structure, can react to stimuli, reproduce, grow, adapt, and maintain homeostasis etc
Movement
Respiration
Sensitivity
Control
Growth
Reproduction
Excretion
Nutrition
