1. Test Review #2!

2. #1.
Below is a simple cladogram. Each little circle is called a node. For each missing description of the node, put a trait that may be represented.

3. #2. All cells have an identical DNA sequence.
The diagrams below show four different cells from the same animal. Which statement below is the most accurate?
All cells have an identical DNA sequence.
Cell number 1 has a longer DNA sequence because it is a longer cell.
The four cells are different shapes because they each come from a different parent organism.
Each cell has ‘activated’ the same sequence of genes even though they look so different.

4. Below is a simple picture of ‘crossovers’ gamete formation
Below is a simple picture of ‘crossovers’ gamete formation. Answer the following questions.
#3.
At which stage does this happen?
Why is this process so important to evolution and survival of the species?
Name a cell in your body that this process happens in (and is impactful).
#4.
#5.

5. #6.
A scientist studies a population of lizards to determine whether or not the population is evolving. Which of the following conditions would be met for the Hardy-Weinberg equation to be in equilibrium (p2 + 2pq + q2 = 1)? Mark all that apply.
Random mating
Large population sample size
There is no migration
There are no mutations
Natural selection is not occurring
#7.
In the equation below, which of the variables represents the heterozygous population? Circle it.
p2 + 2pq + q2 = 1

6. #8. #9-13. We use the Hardy-Weinberg equation to…
Determine if evolution is happening
Measure the speed at which evolution is happening
To prove survival of the fittest
Predict the chance of a certain phenotype surviving an environmental change
The graph below shows a typical carrying capacity for an organism in a given environment. Match the descriptions to the right with the position on the graph.
Carrying capacity
Population exceeds carrying capacity
Species migrates into the environment
Population is growing at its fastest rate
Population is in correction and falls below carrying capacity
#9-13. C E D B A

7. #14.
Below is a graph showing the acidity of a solution containing only bacteria and sugar. Answer the following question.
Which of the following can be inferred from the data given?
The rate of acid production is constant.
As bacteria sit in a solution, the rate of acid production decreases
Sugar is the preferred food source for this strain of bacteria.
The bacteria are eating the sugars and producing an acid by-product.

8. Make sure you correct the ones you missed and keep. This will be
Answers!
Make sure you correct the ones
you missed and keep. This will be
for a grade later!

9. In each oval, you could put anything that distinguishes the two organisms apart. I chose (from bottom to top) the following: vertebrae (spine), four limbs, eggs.
The key to this answer is here  “The cells all come from the same animal.” As long as there is no egg or sperm cell here (and there isn’t), all of the cells have IDENTICAL DNA sequences!
Crossovers occur in metaphase. This is when all the chromosomes are intertwined in the middle of the cell.
Crossovers are important because it gives advanced organisms, like humans, individuality. Without crossovers, we would all be EXACTLY the same. Different individuals equal survival of the fittest. This is THE reason organisms evolve!!
Crossovers actually occur in EVERY cell of the body during replication, but are meaningless in all cells except egg and sperm cells. It is meaningless because the pieces of DNA that get traded are exactly the same. It’s like swapping an ace of spades for an ace of spades in a poker hand. In egg and sperm cells, crossovers give us slight variations of ourselves that we can pass on to our offspring.

10. All of these things apply
All of these things apply. For the Hardy-Weinberg equation to hold true, no evolution or no change in the gene pool can occur. Any of these five things would change the gene pool.
Heterozygotes are one of each kind of allele. Bb, Zz, Yy, etc. Heterozygotes in the HW equation is represented by the 2pq. Homozygous recessive (bb) individuals are q2 and homozygous dominant (BB) individuals are p2.
The HW equation is used to determine if evolution in two separate populations (or the same population over time) is happening. So the answer is A. E C A B D
The rate of acid production is constant. The rate of acid production is increasing exponentially as noted by the curved line.
As bacteria sit in a solution, the rate of acid production decreases. The rate of acid production is increasing (line goes up!)
Sugar is the preferred food source for this strain of bacteria. There is no way of telling what these bacteria prefer to eat given the data.
The bacteria are eating the sugars and producing an acid by-product. With only bacteria and sugar in the sample, you can safely infer that the bacteria are eating the sugar and in doing so are producing an acid.