RETEST ELM 4.3

Which of these represents the number of chromosomes in cells before and after the process of meiosis?

• n --> n
• n --> 2n
• 2n --> n
• 2n --> 2n

What does heterozygous mean?

• An organism that has the same genes for a trait (TT or tt)
• An organism that has different genes for a trait (Tt)
• When neither gene is fully dominant; offspring is a mixture of both
• the different forms of a trait (hair color--> brown, blonde, red

W=white hair
w= non-white hair
If you cross a horse with WW and a horse with ww what fraction of the offspring would be expected to have white hair?

• none
• 3/4
• 1/2
• all

Two heterozygous (Tt)tall pea plants are crossed. Which describes their offspring?

• 50% tall and 50% short
• 75%tall and 25% short
• 100%short

Which event during meiosis causes GENETIC VARIATION? 

• crossing over 
• protein synthesis 
• cytokinesis 

What is a phenotype?

• The expression of a trait; what you see.
• refers to the genetic makeup of an individual
• An organism that has the same genes for a trait (ex. TT or tt)
• the passing of traits from parent to offspring

B=brown eyes
b= blue eyes
What is true about two brothers that have brown eyes?
One has genotype BB the other Bb.

• they have same phenotype and genotype
• they have different genotypes and phenotypes
• they have same phenotype but different genotypes
• they have same genotype but different phenotypes

B = brown fur  b = white fur
In the punnett square, what is the probability for white fur? 

• 0%
• 25%
• 50%
• 75%

In mussels, the allele for brown coloring (B) is dominant, and the allele for blue coloring(b) is recessive. For which parental genotypes are 100% of the offspring expected to be blue?

• BbxBb
• bbxbb
• BBxbb
• BBxBB

A change in gene linkage during meiosis would most likely result from...

• DNA replication
• ATP synthesis
• crossing over
• independent assortment