cell specialisation Flashcards
what is cell specialisation
the process where unspecialised cells develop into cells with specific structures and function
how does cell specialisation occur
- certain genes are swithced on or off
- specific proteins are produced
- cell changes its shape and function
what are the 3 main types of animal tissues
- epithelial tissue- covers surfaces
- muscle tissue
- nervous tissue
how are red blood cells adapted to their function
- biconcave- increase SA for oxygen diffusion
- no nucleus- more space for haemoglobin
- flexible- allows squeezing through capillaries
what controls cell differentiation
gene expression, where certain genes are switched on or off by chemical signals
what role does DNA play in cell specialisation
all cells contain the same DNA, but different cells express different genes, leading to the production of different proteins
how do transcription factors influence cell differentiation
activate specific genes-> proteins needed for speciialisation are made
suppress unnecasary genes-> prevent production of irrelevant proteins
what is DNA methylation
addition of methyl group to cytosine bases in DNA, typically silencing gene expression
how does DNA methylation affect gene expression
prevents transcription factors from binding to DNA, blocking transcription and turning the gene off
what is histone acetylation
addition of acetyl group to histone proteins, leads to gene activation
how does histone acetylation affect gene expression
loosens chromatin structure, allowing RNA polymerase and transcription factors to access DNA, activating gene transcription
what is polygenic inherticance
multiple genes control a single trait, resulting in continuos variation
example of polygenic trait in human
height
what is the normal distributoin curve in polygenic inheritance
bell shaped curve, where most individuals have an intermediate phenotype
