Body plans

Created by

Evie W

Cards (23)

What is a homeobox gene  
A group of genes which contain a homeobox
What is a homeobox
A section of DNA that is 180 base pairs long coding for a part of the protein 60 amino acids long
What does a Homebox do
binds to dna and switches genes on and off
What is another name for a homeobox gene
Regulatory gene
What is radial symmetry
See in diploblastic animals like jellyfish they have no right and left only a top and bottom
What is bilateral symmetry  
They have a left and right and a head and tail
what is asymmetry  
Seen in sponges no line of symmetry
What is mitosis
Results in cell division and proliferation
What is apoptosis
Programmed cell death
How does apoptosis shape body parts
By removing unwanted cells and tissues
When do factors affecting they expression of regulatory genes have the biggest impact
When the organisms is growing
What is a hox gene
One type of homeobox gene that are responsible for the positioning of body parts
Where are hox genes found
In gene clusters
How many hox gene clusters do mammals have
4 clusters on different chromosomes
How many hox genes do humans have
39 hox genes
how are body plans usually represented
As cross sections through an organism showing the fundamental arrangement of tissue layers
What is a diploblastic animal
Have two primary tissue layers
What is a triploblastic animal
Animals which have 3 primary tissue layers
What is a common feature of animals
They are segmented e.g the rings or worms or the vertebrate back bone of humans
What do hox genes in the head control
the mouthparts
Where do individual vertebrates or associated structures develop from
Segments of the embryo called somites
what is an example where a drug effects hox genes
Thalidomide given to pregnant women in the 50s and 60s prevented normal expression of hox gene giving babies shorter limbs
What part of a protein does a homeobox code for
Homeodomain