Bio Lab Exam 2

Question 1

How to tell karyotype is male or female?

Answer 1

23rd chromosome
Female: 2 X (long)
Male: 1 X, 1 Y (one long, one short)

Question 2

what is Klinefelter Syndrome?

Answer 2

An extra X chromosome (3 sex chromosomes)

Question 3

What meiotic event would have to occur to cause Down’s syndrome?

Answer 3

Nondisjunction would cause this

Question 4

What sex chromosomes does an abnormal sperm have to carry in order to produce an XXY offspring when it combines with a normal egg?

Answer 4

It would carry an extra X chromosome. The sperm would carry not just the Y but an X too

Question 5

X^cY

Answer 5

Colorblind

Question 6

If a heterozygous woman with normal vision and a man with normal vision produce a colorblind Turner’s child, how can this be explained?

Answer 6

There is still a 25% chance of their child being colorblind. The mom provided the chromosome X^c bc the father can’t provide a chromosome due to nondisjunction

Question 7

Is it possible for a colorblind male and a female that is not colorblind to produce a male child that is chromosomally normal, but colorblind?

Answer 7

It isn’t possible for them to produce a male child that is colorblind

Question 8

Why are there no instances of individuals with only a Y chromosome?

Answer 8

An X chromosome is needed for survival so these individuals did not make it through fetal development

Question 9

Is this evidence for differences in the genetic content between the X and the Y chromosome.

Answer 9

Yes bc the X chromosome is much larger containing more genetic info while the Y chromosome is smaller and gives males their characteristics

Question 10

What will travel father in a gel?

Answer 10

Small fragments

Question 11

Is DNA positively or negatively charged?

Answer 11

negatively charged

Question 12

what are restriction enzymes?

Answer 12

endonucleases which catalyze the cleavage of the phosphate bonds within both strands of DNA

Question 13

Other than covid-19, what are some other illnesses that coronaviruses are known to cause?

Answer 13

Pneumonia, organ failure, respiratory distress.

Question 14

what are some symptoms of covid-19?

Answer 14

trouble breathing, fever, sore throat, loss of smell, kidney failure, loss of appetite

Question 15

the human genome is made of DNA. what is the genome of coronavirus made of?

Answer 15

a single stranded RNA genome wrapped in a helical capsule.

Question 16

In coronaviruses, what does the nucleocapsid (N) protein do?

Answer 16

forms a helical capsid which protects the RNA genome

Question 17

What does RT-PCR stand for and what is this test designed to identify when testing for COVID?

Answer 17

It stands for Polymerase chain reaction. It is used to detect viral genome, signifying active infection.

Question 18

In this PCR test, how many genetic regions are targeted?

Answer 18

3

Question 19

Describe each of the genetics regions that the PCR test targets.

Answer 19

The first two sets targets regions in the SARS-COV-2N protein. The third set targets the human housekeeping gene RP.

Question 20

On the gel, how many bands are expected to see if someone doesn’t have covid?

Answer 20

one band

Question 21

On the gel, how many bands are expected to see if someone has covid?

Answer 21

Three bands

Question 22

what is a RFLP and why does it cause bands of diff sizes?

Answer 22

It is variations in the length of the fragments bc of the number of repeats between cut sites. It is caused by restriction enzymes.

Question 23

what function do repetitive base sequence have in DNA? what percentage of the mammalian genome do they make up?

Answer 23

They have no known function. Ten to fifteen percent.

Question 24

Could two people ever have the same DNA fingerprint? Why or why not?

Answer 24

It is possible. The chance is 1 in 30 billion. There is a very tiny percentage of it happening bc of multi band patterns and different alleles

Question 25

what does RFLP STAND FOR?

Answer 25

Restriction Fragment Length Polymorphism