Biology Final Lab Practicum 2023

What are the two kinds of genetic abnormalities that may be observed through karyotyping?

Numerical and Structural errors. Numerical errors are whole chromosomes that are missing or extra. Structural errors are when part of the chromosome is missing or in the wrong position.

What is the genetic composition of a normal male?

46, XY

6 signs of a chemical reaction:

bubbles, color change, temperature change, odor, sound, light

what were the initial and final colors of the rust?

grey to brown

what was the temperature change of the rust?

\+ 18 degrees Celcius

Did iron lose or gain electrons (what happened as a result)

lost, oxidized

Did oxygen lose or gain electrons (what happened as a result)

gained, reduced

Why is it more accurate to call mitosis “nuclear replication” rather than cellular division?

In mitosis, the nucleus is duplicated and divided to form 2 daughter nuclei. However, the cell is not divided in mitosis. This happens in cytokinesis.

Why are onion root tips selected for the study of mitosis?

They contain actively dividing cells, which makes it easy to observe the mitotic phases.

Many of the cells of the root meristem are not undergoing mitosis, rather they are in a stage called:

interphase

After cell division ends and the cell produces the organelles and molecules required for its survival, the cells will exit the cell cycle and enter the ____ phase. Why is it incorrect to say that these cells are “resting”?

G0, the cells are still metabolically active.

If my observations had not been restricted to the area of the root tip that is actively dividing, what would I have seen?

many more cells undergoing interphase

what evidence shows that mitosis is a continuous process?

there are multiple cells undergoing the same phase, and some cells in between the 2 phases.

The onion plant began as a single cell. How many chromosomes are in each of the cells that you observed?

2x

Where would you find cells undergoing meiosis in plants:

the germ cells

Where would you find cells undergoing meiosis in animals:

reproductive systems

where are the rarely-dividing tissue in plants:

differentiated plant cells

where are the rarely-dividing tissue in animals:

neurons and heart muscles

How do the percentages of tasters vs non-tasters compare between PTC and thiourea?

The percentages of tasters vs non tasters of PTC and thiourea were similar, but there were more PTC tasters than thiourea tasters.

What general statement can you make about being a taster and a non-taster relative to PTC and thiourea?

While both PTC and thiourea may have a similar taste, not all PTC tasters are thiourea tasters or vice versa.

How does the ability to taste sodium benzoate compare to the ability to taste PTC or thiourea?

The ability to taste sodium benzoate is divided into multiple subcategories, while the ability to taste PTC or thiourea only determines if one can taste the bitter taste.

How would you describe the variation in individuals in their ability to taste different substances?

There is a diverse variation in individuals regarding their ability to taste different substances.

Is the ability to taste inherited?

Yes, because the ability to taste PTC is inherited.

Does the mRNA model more closely resemble the DNA strand from which it was transcribed or the complementary strand that wasn’t used?

The mRNA strand resembles the complementary strand more because both strands bond to the original strand in the same matter.

Explain how the structure of DNA enables the molecules to be easily transcribed. Why is this important for genetic information?

When the DNA is “unzipped,” mRNA is able to be formed by simply creating a “mirror” image of the DNA strand. Since the process is simple, this prevents a loss or change in the mRNA strand.

Why is RNA important to the cell? How does an mRNA strand carry information to DNA?

RNA controls protein synthesis, which are important molecules for the cell’s function. mRNA carries genetic information in its nucleotides, which are attached in transcription.

What is in the test tubes?

1: 3ml Water and 3ml Milk. 2: 3ml Water and 3ml Yeast. 3: 3ml Milk and 3ml Yeast. All had 3 drops of methylene blue

What happened to test tube one?

It stayed dark blue.

What happened to test tube two?

It became lighter blue in around 4 minutes.

What happens to test tube three?

It became very white in around 3 minutes.

What does the white represent?

lack of oxygen

Why did the color change?

yeast decomposes

What happened that caused the peppered moths to change colors?

the Industrial Revolution

What color did the peppered moths change to and from?

white peppered flakes to fully black

Did you pick up the worms easier with chopsticks or spoon?

chopsticks

DNA dissolves in water, but not in alcohol. Explain what happened when the alcohol came in contact with the strawberry extract during the DNA extraction.

When the alcohol came in contact with the strawberry extract, the alcohol and strawberry mixture separated with the alcohol on top. After a few minutes, the strawberry DNA collected on top in clumps.

Describe the DNA you extracted. How was the appearance of the DNA similar or dissimilar to what you have learned about DNA structure?

The DNA that was extracted was white and slimy. This is dissimilar to what we have learned about, which is that DNA has a double-helix structure. However, this DNA was clumpy and not in a double-helix structure.

If a molecule of DNA is invisible even under a microscope, how can you see the strawberry DNA you extract?

You can see the DNA molecules because they are so clumped together, making the DNA visible to the naked eye.

Can you see the double helix structure of the extracted DNA under the microscope? Why or why not?

You cannot see the double-helix structure under a microscope because it is so microscopic that even a powerful microscope cannot help you see the structure.

Is the white, stringy stuff DNA only, or is it a mix of DNA and RNA? How do scientists know?

The white, stringy stuff is only DNA. Scientists know by looking at the sugar. DNA has deoxyribose as the sugar, while RNA has ribose.

How long will the extracted DNA last? Will it eventually degrade and disappear?

The extracted DNA will not last for long if not stored in the proper conditions. Thus, external factors will lead to the DNA degrading.

Using information you have gained through biotechnology, explain what you could do with the extracted DNA.

With the extracted DNA, you could transfer it into an egg cell, which is then grown into an egg cell, which is then grown into a blastocyst. This can be used for reproductive or therapeutic cloning.

In order to study human genes, scientists must first extract the DNA from human tissues. Would you expect the method of DNA extraction for human DNA to be the same as the method you used to extract DNA from wheat germ? Why or why not?

The method would not be the same because animal cells do not have more protective structures, like cell walls. Thus, the form of extraction would be very different.

Animal cells are different from plant cells because plant cells exhibit polyploidy. Explain the term polyploidy and compare it to animal cells.

Polyploidy is a condition in which cells have more than 2 sets of chromosomes. Most animal cells are diploid, which are 2 sets of chromosomes.

Strawberries are octoploid whereas bananas are triploid. DNA is extracted from 2 mL of strawberry extract. DNA is also extracted from 2 mL of banana extract. Will the difference in sets of chromosomes affect the amount of DNA extracted from the 2 samples.

There may be a small difference in the volume of DNA. This is because strawberries have more chromosomes per cell, but 2 mL is a small amount. Thus, the strawberry DNA extract may be larger, but by a negligible amount.