Of the multiregional versus Out-of-Africa hypotheses, which model is supported best by the data? Briefly state how the data support that particular model.
(please don't copy paste from websites)
In: Biology
Glucose is classified as a ________.
Select one:
a. simple sugar
b. dietary starch
c. polysaccharide
d. dietary fiber
In: Biology
In: Biology
Heterochromatic regions at the ends of chromosomes that function to control how many times the cell will divide are called:
| centromeres. |
| euchromatin. |
| telomeres. |
| satellites. |
| DNA hubs. |
An individual has two homologs of chromosome 21 and both homologs came from the same parent. Which phenomenon caused this condition?
| deletion |
| duplication |
| aneuploidy |
| polyploidy |
| uniparental disomy |
Although natural selection works to decrease the frequency of deleterious alleles in a population's gene pool, deleterious recessive alleles often remain in the gene pool. What maintains deleterious recessive alleles in a population?
| Ability to be hidden in heterozygotes |
| Migration |
| Nonrandom mating |
| Natural selection |
| Evolution |
In: Biology
In: Biology
Currently a lot of research is happening about the corona virus. What type of a laboratory should be used to conduct these investigations and why?
In: Biology
What are mad cow disease and scrapie? Explain the cause and of these diseases and their importance to the meat industry?
In: Biology
Compare between oxidase and catalase enzymes in microbial identification. Provide at least one example for each enzyme.
In: Biology
Discuss the functions of teichoic, dipicolinic acids chitin in microorganisms.
In: Biology
Question 180
KRAS mutations in pancreatic cancer (choose all that apply):
Question 191
Which of the following is an imaging test used to diagnose pancreatic cancer? Choose all that apply.
Question 201
Immune cells can promote tumor cell proliferation via activation of:
Question 210
Which of the following immune cell types plays a role in establishing a pre-metasatic niche?
In: Biology
Describe the role of Shh in neural tube development
In: Biology
Performing Monohybrid Crosses
A monohybrid cross is addressing the inheritance of one gene. Answer the following questions:
Question 1:
Drosophila melongaster, more commonly known as the fruit fly, can have red or white eyes. You breed a red-eyed fly to a white-eyed fly and get 50 offspring that all have red eyes. Which trait is dominant?
Question 2:
Consider an offspring from the previous question. Its phenotype is red eyes.
What is its genotype? (Circle one of the choices below)
Homozygous dominant, Heterozygous, or Homozygous recessive
Question 3: (2pts)
Next, you perform a cross of two heterozygous, red-eyed flies. They have 100 offspring. How many of these offspring do you predict will have red eyes? Show your work using a Punnett square. [Use letters R and r to designate the alleles]
Question 4:
Suppose you found a fly that had escaped and was flying around your lab. He has red eyes, but you do not know his genotype. To find out, you cross him with a white eyed fly (since you know her genotype). The result is 50% white eyed and 50% red eyed offspring. What is the escaped fly’s genotype? Explain how you know.
X-linked Inheritance
Consider this imaginary animal, the tree rat. They are usually black, but sometimes they can be purple. The allele for the purple color is X-linked. You manage to capture two of these animals from the same family, a black female and her purple male offspring.
Question 5:
What is the genotype of the black female mother?
Question 6
Do you know the phenotype of the father based on the male offspring? Why or why not?
Question 7: (2pts)
Next you breed the tree rats to each other (inbreeding is acceptable in this case). What percent of the offspring do you expect to be purple? Are any of them female? Use a Punnett square to show your work. [Use the letters B (black) and b (purple) to represent the alleles.]
In: Biology
1. The chicken ovalbumin gene has five introns and interrupting the coding sequences or exons. How many R-loops will be observed if DNA of the gene and cytoplasmic mRNA are mixed under conditions that allow hybridization? How many R-loops will be observed if nuclear pre-mRNA is used?
In: Biology
Why can't people donate blood who recently have:
a. had a tattoo or a recent piercing?
b. been recently treated with antibiotics?
c. are low on iron?
d. if you don't weigh at least 110 lbs?
e. is a man who has had anal intercourse with another man?
f. have had sex with a sex worker in the past 12 months?
g. previously received blood transfusions during a medical procedure?
h. been in a relationship with a drug user (injected)?
In: Biology
In: Biology