DNA 1 - MT2 - Part 3 Flashcards
Gene
Is a segment of a DNA molecule in a cell that has the information needed to construct a specific protein
Gene expression
The appearance in a phenotype of a characteristic or effect attributed to a particular gene
What do genes do?
They encode proteins, which carry out much of the work in the cell
What does a chromosome consist of? (2)
- One very long DNA molecule
2. Many associated proteins
What amount of chromosomes do people with down syndrome have?
Less chromosomes
What amount of chromosomes do people have with variation in gender?
More chromosomes
- typically 3
What can missing or extra chromosomes result in?
Can be fatal
Histone
Any of a group of basic proteins found in chromatin
What do chromosomes vary in?
Size
What contains genetic information?
DNA molecule
What do proteins help with? (4)
- Packing the DNA efficiently
- Extracting the genetic information from the DNA in usable form
- Replicate the DNA
- Repair damaged DNA
What can damage DNA?
Body temp
What is the genome?
Is all of the organisms genes, collectively
What are all the proteins known as?
Proteome
What does a typical cell have?
2 versions of each gene, arranged along 2 versions of each chromosome
What is the name of the chromosomes on which they are arranged? (2)
- Homologous chromosomes
2. Homologues
Allele
Specific version of a specific gene
The cell division process that leads to formation of gametes in people/animals is called what?
Meiosis
What kind of division is meiosis?
Reductional
- the daughter cells resulting from meiosis have half the chromosomes of the mother cell
- each gamete will contain half the chromosomes of the mother and will be genetically distinct from every other gamete
Meiosis
The process of division which selects chromosomes from packaging into gametes
Where does a lot of variation happen?
Meiosis
- cell division/ replication
What happens in fertilization?
The egg nucleus and the sperm nucleus contribute an equal number of chromosomes to the zygote
What does the Y chromosome determine?
Whether it will be a male or not
Where is the Y chromosome only passed on from?
From father to son
Maternal inheritance
Energy organelles (mitochondria) carry a few genes and are almost always inherited from the egg - passed on from the mother
What phenotype do you get from XX?
Female
What phenotype do you get from XY?
Male
Where do these chromosome pair up?
During meiosis
