3.2 Chromosomes Flashcards
Define chromosome.
A long DNA molecule carrying genetic information.
Name where chromosomes can be found in prokaryotes.
In a naked single circular molecule of DNA, and sometimes in extra plasmids.
Name where chromosomes can be found in eukaryotes.
In the nucleus, stored as multiple linear molecules of DNA.
Roughly describe the term diploid.
Two sets of chromosomes/somatic cells.
Roughly describe the term haploid.
One set of chromosomes/gametes.
Name what happens when haploid cells fuse.
The diploid cell can grow into a new organism.
Define homologous chromosomes.
The paired chromosomes inherited from both parents in sexually producing animals.
Name the characterizing feature in species.
The chromosome number.
Name the 2 karyotypes most commonly used to identify the number of chromosomes in a species.
- Amniocentesis
2. Chronic villi sampling
Describe amniocentesis.
Cells are collected from the amniotic fluid of the mother at roughly 16 weeks of pregnancy. There is a 0.5% chance of miscarriage.
Describe chronic villi sampling.
Cells are collected from the placental tissue at roughly 11 weeks. There is a 1% chance of miscarriage.
Describe John Cairn’s technique and experiment for measuring the length of DNA strands once uncoiled.
Radioactive thymine was incorporated into the cell’s DNA, the chromosomes were fixed to a photographic surface and silver bromide was added. The radiation which was added after converted the silver ions into visible grains.
Name the number of chromosomes humans have, and the diploid number.
23 chromosomes, with a diploid number of 46.
How many /23 chromosomes are autologous?
22.
What pair is the sex chromosome?
The 23rd pair.
