The Work of Mendel
What are different forms of a gene called?
Alleles
The physical characteristics of an organism is called its...
hint: describing it in words
phenotype
Describe incomplete dominance
Blending
Unlike mitosis, meiosis results in the formation of...
a. one haploid gamete
b. three diploid gametes
c. four diploid gametes
d. four haploid gametes
d. four haploid gametes
What is the example of a hybrid Mr. Lecher used in class?
a Mule
Organisms that have two identical alleles for a particular trait are said to be...
Homozygous
A Punnet square is used to determine the...
a. probable outcome of a cross
b. actual outcome of a cross
c. result of incomplete dominance
d. result of meiosis
a. probable outcome of a cross
Characteristics of an organisms are determined by two factors. What are they?
1. Genes
2. Environment
What is occurring during Prophase 1?
Homologous pairs are condensing and crossing-over.
What is the number of cell divisions in Meiosis?
2 cell divisions
Mendel had many stocks of pea plants that were true-breeding. What does the term true-breeding mean?
Two identical alleles.
What is the probability that a gamete produced by a pea plant heterozygous for stem height (Tt) will contain the recessive allele.
50%
A pink flower (Rr) is crossed with a white flower (rr). what is the chance that a seed from this cross will produce a red flowered plant (RR)?
a. 0
b. 1/4
c. 1/2
d. 1
a. 0
Suppose that an organism has the diploid number of 18. How many chromosomes does this organism's gametes contain?
9 Chromosomes
What principle states that during gamete formation genes for different traits separate without influencing each other's inheritance?
principle of Independent Assortment
What is the definition of homozygous?
Two alleles are the same.
ex: TT,BB,rr,yy
What are the alleles of two heterozygous tall green parents.
TtGg
Explain Codominance
hint: you can explain using an example
White X Red= white/red
Describe what is occurring during Anaphase 2 during meiosis.
Spindle fibers are pulling chromatids to opposite ends of the poles.
Variation in human skin color is an example of
Polygenic traits
What is the Law of Segregation?
Diploid organisms possess two alleles for each trait, which separate (segregate) during gamete formation (meiosis).
Cross a homozygous purple, heterozygous tall with a heterozygous purple, heterozygous tall.
What are the alleles for the parents.
PPTt x PpTt
What are polygenic traits.
Traits that are produced by the interaction of several genes.
What 3 things are occurring during Prophase 1 during Meiosis?
1. Chromosomes pair with its homologous pair
2. Crossing over occurs
3. Chromosomes are condensing
The farther apart two genes are located on a chromosome, the...
a. less likely they are to be inherited together
b. the more likely they are to be linked
c. less likely they are to assort independently
d. less likely they are to be separated by crossing over.
a. less likely they are to be inherited together