Lect 32 Flashcards
Mutants give insights into gene function, explain how
Isolate mutant in selected process, Identify gene that has become mutated, Draw conclusions on gene function
What is the best plant for molecular genetic research?
Arabidopsis thaliana
Arabidopsis thaliana is widely used due to its simple genome and short life cycle.
What is a key advantage of Arabidopsis for genetics related to its size?
Small and easy to grow
Arabidopsis is a model organism in plant genetics due to its manageable size.
What is the generation time of Arabidopsis from seed-to-seed?
6 weeks
This rapid generation time allows for efficient genetic studies.
How many seeds can a single Arabidopsis plant produce?
Hundreds of seeds
This high seed yield facilitates extensive genetic experimentation.
Is Arabidopsis self-fertile?
Yes
It can also be crossed with other plants for genetic studies.
What is one method that makes genetic manipulation easier in Arabidopsis?
Easy to produce mutants
This trait allows researchers to study gene function and mutation effects.
List advantages of Arabidopsis for genetics:
Advantages of Arabidopsis for genetics:
1. Small and easy to grow
2. Rapid generation time: 6 weeks seed-to-seed
3. Hundreds of seed per plant
4. Self fertile and can also be crossed
5. Easy to produce mutants
Explain seed mutagenesis
In seed mutagenesis, seeds are exposed to mutagenic agents like chemicals or ionizing radiation (e.g., X-rays or gamma rays) to induce genetic mutations. The goal is to create a few mutations, not overwhelming the genome. The treated seeds produce the M1 generation, where mutations occur, but phenotypic changes are not yet obvious. These plants are then harvested for seeds that form the M2 generation, where beneficial mutations can be identified and selected for further breeding.
What is the ploidy level of Arabidopsis?
Diploid
How many homologous pairs of chromosomes does Arabidopsis have?
5 homologous pairs
What is the probability regarding gene mutation in Arabidopsis?
Very high probability that a given gene will only be mutated on one of the chromosomes for the M1 generation
What is the genetic status of M1 plants in Arabidopsis?
Heterozygous for mutant gene
Explain the process to get M2 generation
What is the size of the Arabidopsis genome?
135,000 kbp
What advantage does the small genome of Arabidopsis provide for molecular biology?
Enabled full genome sequence to be obtained and helps gene isolation
What percentage of Arabidopsis’s genome is made up of protein-encoding genes?
About 40%
True or False: Arabidopsis has a high amount of repetitive DNA in its nucleus.
False
What is notable about the amount of non-coding DNA in Arabidopsis?
It has relatively little non-coding DNA
How does the proportion of protein-encoding genes in Arabidopsis compare to larger genomes?
It is a much higher proportion than in larger genomes
Fill in the blank: Arabidopsis has relatively little _______ DNA and non-coding DNA in its nucleus.
repetitive
How many protein-encoding genes does Arabidopsis have?
27,655 protein-encoding genes
What is a very easy method to genetically transform Arabidopsis?
Agrobacterium ‘floral dip’
This method is commonly used in plant genetics for its efficiency in introducing new genetic material.
What can be isolated in Arabidopsis?
Genes corresponding to mutants
This refers to the ability to identify specific genes that are associated with mutant phenotypes in the Arabidopsis plant.
