11.1 - The Work of Gregor Mendel
Specific physical characteristics are called
traits
How would you write a homozygous recessive genotype?
Both letters would be lowercase
If Sarah wants to produce purple flowers, what kind of inheritance would be useful here?
Meiosis results in
4 genetically different cells
What is a Mendellian trait?
There are only two alleles that follow the typical principle of dominance.
What does it mean to be purebred or hybrid?
Purebred means that both parents passed on the same version of the trait while hybrids inherit difference alleles.
Type of inheritance where two different alleles blend together
Incomplete Dominance
Describe the difference between diploid and haploid cells.
Diploid cells are somatic and contain the full set of chromosomes (46 in the human body). Haploid cells only contain half of the parents genetic information and are each genetically unique. Human gametes are considered haploid as they only have 23 chromosomes.
What did Mendel observe when he crossed a purebred tall pea plant with a purebred short pea plant?
Every trial he did resulted in tall pea plants being produced.
True or False: Punnett squares are 100% accurate.
False
If the allele for black feather color (B) and white feather color (W) in chickens are codominant, then their children would have what kind of feathers:
Black and white feathers or checkered
Describe the process of crossing over. When does it occur?
Crossing over is the swapping of genetic material that occurs during meiosis. During the formation of egg and sperm cells, paired chromosomes from each parent align so that similar DNA sequences from the paired chromosomes cross over one another. Crossing over results in a shuffling of genetic material and is an important cause of the genetic variation seen among offspring. This process only occurs during Prophase I.
What did Mendel observe when he crossed his F1 generation?
75% of the plants produced were tall while 25% were short.
Describe the difference between genotype and phenotype.
Genotype refers to the individual genes that are inherited from each parent while phenotype refers to the physical expression of the trait.
What is the pattern of inheritance called when there are three or more alternative forms of a trait.
Multiple alleles
List four differences between Mitosis and Meiosis.
1. Mitosis produces somatic (body) cells. Meiosis produces gametes.
2. Mitosis has 1 set of divisions while meiosis has 2.
3. Mitosis produces 2 cells. Meiosis produces 4.
4. Cells produced from mitosis are genetically identical while cells produced from meiosis are genetically different and unique.
Mendel concluded that segregation was occuring in the pea plants. When did he believe this segregation occured?
During the formation of gametes
Sarah wants to only produce hybrid offspring. In order to do this, what kind of genotypes would have to be crossed?
Both parents would have to be homozygous, but one will have to be homozygous dominant and the other homozygous recessive.
Give 2 examples of multiple alleled traits and 2 examples of a polygenic trait.
Multiple alleled: Blood type, rabbit fur, skin tone
Polygenic: Height, hair color, skin pigment
Briefly describe the phases of Meiosis.
Be able to describe the differences between Meiosis I and Meiosis II.