3.2 Flashcards
(13 cards)
What are chromosomes like in prokaryote’s?
-They are a single continuous loop
-They do not contain histones
-They do not come in pairs because there is no sexual reproduction
What are plasmids?
Small loops of DNA that are separate from the main chromosome found in some bacterial cells
What are features of eukaryotic chromosomes?
-The DNA is wrapped around histone proteins, forming a nucleosome
-The nucleosome’s then coil around each other, forming a more dense structure, which is the chromosome
- They are linear
-They come in pairs.
Why does the cell form chromosomes?
- Organises, genetic material, so nothing get lost or damaged during cell division.
What do you histone aid in doing during gene expression?
They help control gene expression by wrapping sections of DNA tightly and making sure that the transcription enzyme can’t get to them. If those jeans can’t get transcribed, they can’t be expressed.
What are homologous chromosomes?
A pair of chromosomes ( one from each parent) that are the same length and contain the same jeans in the same location
What are diploid cells?
-2n
- somatic/ body cells
- produced by mitosis
- chromosomes are in pairs
In humans 2n=46
What are haploid cells?
- n
- gametes / sex cells
-Produced by meiosis - chromosomes are not in pairs
- in humans n=23
What is the difference between a karyogram and a karyotype
A karyogram is the visualisation of chromosomes and a karyotype is a diagnosis based on the karyogram
What are autosomes?
Chromosomes which do not determine sex
Based on chromosomes, how do you know if it is male or female?
Females have 2X chromosomes and males have an XY
What is autoradiography?
When images of radioactive substances are captured
When can auto radiography be used?
To show that bacterial DNA is a single loop, and then it replicates buy a zipping.
