Genetics Study Guide Flashcards
(43 cards)
What is meiosis?
A type of cell division that produces reproductive cells (gametes/sex cells) with half the number of chromosomes (haploid)
What type of cells does meiosis occur in?
Sex cells (gametes)
What is crossing over?
The exchange of genetic information between homologous pairs of chromosomes
What stage of meiosis does crossing over occur?
Prophase I
What are some differences and similarities between mitosis and meiosis
- Mitosis and meiosis are both forms of cell division
- Mitosis produces 2 daughter cells
- exact copies of the original cell (somatic)
- 46 chromosomes (diploid cells)
- Meiosis produces 4 daughter cells
- sex cells (gametes)
- 23 chromosomes (haploid)
Mendel’s Three Laws of Genetics
- Law of Segregation
- Law of Dominance
- Law of Independent Assortment
The Law of Dominance states:
certain alleles can be more powerful than others
- dominant alleles always show their traits
- recessive alleles only shown when no dominant allele is present
The Law of Segregation states:
only one of the two alleles is transferred to a sperm or an egg
- each gamete carries only one allele for each gene
- two alleles, one allele from each parent (ex: PARENT: Tt
GAMETE 1: T
GAMETE 2: t)
The Law of Independent Assortment states:
the alleles of two (or more) different genes get sorted into gametes independently from one another
Ex: flower color and height.
For example, if you’re looking at two traits, like flower color and plant height, the gene for flower color will assort independently from the gene for plant height when the gametes are formed.
Flower color: C
Plant height: H
They are not inherited differently or dependent on each other.
How many alleles do you have for each trait?
When do these alleles separate?
2; Anaphase I
Some advantages of using pea plants for genetics experiments:
- Reproduce quickly
- Produce many offspring
- Easily identifiable traits
Possible Genotype(s) for Blood Types (ALL)
A: AA, Ai
B: BB, Bi
AB: AB
O: ii
Possible Genotype(s) for Blood Type A
AA, Ai
Possible Genotype(s) for Blood Type B
BB, Bi
Possible Genotype(s) for Blood Type AB
AB
Possible Genotype(s) for Blood Type O
ii
What genotype represents a male
XY
What genotype represents a female
XX
How does gel electrophoresis work
separates the molecules (like DNA) by size
- samples loaded into a gel (agarose)
- DNA placed into wells
- electric current applied (DNA is negative, moves to positive side)
- restriction enzymes cut DNA into tiny pieces
- smaller ones faster
- use DNA bands to compare how closely related two organisms are
What is epigenetics
the science of how genes change from environmental factors
What is CRISPR
a laboratory method of gene editing, making a change to specific bases in DNA
What is Sickle Cell Disease
a single gene disorder caused by a genetic variation (mutation) in the beta-globin gene, causing the cell to be sickle shaped
- beta-globin codes for a protein that’s part of hemoglobin
- a small genetic change occurs in the beta-globin gene which changes the protein, resulting in ‘sickle’ shaped red blood cells
What is Sickle Cell Disease caused by
a genetic variation (mutation) in the beta-globin gene
- beta-globin codes for a protein that’s part of hemoglobin
- a small genetic change occurs in the beta-globin gene which changes the protein, resulting in ‘sickle’ shaped red blood cells
Do 1 sample problem
*Be prepared to read a pedigree and predict the genotypes of the individuals in the pedigree.
