Category: Biology

 Describe the regulation and the phases of the menstrual cycle.When is a woman most fertile? What are the physical and emotional changes that tend to occur during this cycle, and why do these occur?

Describe menstrual cycle

From an anatomical and physiological perspective, describe the menstrual cycle. Pay special attention to the hormonal changes during the cycle. When is a woman most fertile? What are the physical and emotional changes that tend to occur during this cycle, and why do these occur? (15 marks)
Describe the biological and physiological aspects of the sexual response cycle as described by Masters and Johnson. Note: Many researchers and sexual health educators feel the response cycle is incomplete. As part of your response, include your thoughts regarding whether the response cycle accurately represents what happens to the human system during sexual activity. Also, comment on the reasons why many researchers and educators feel it is incomplete. (15 marks)

The Menstrual Cycle

Describe the regulation and the phases of the menstrual cycle.

 What is the probability of the couple having a daughter with haemophilia?If height were entirely genetically controlled, what concordance would you expect between monozygotic twin pairs? Explain your answer.

Genetics

ABO blood groups in human are an example of discontinuous variation, whereas height is an example of continuous variation. Describe how these two examples differ in terms of:

Genetic control (i.e. the number of genes involved).

The effect of the environment on each characteristic.

The range of phenotypes.

Give one other example of continuous variation and one other example of discontinuous variation.
Continuous
Discontinuous

If height were entirely genetically controlled, what concordance would you expect between monozygotic twin pairs? Explain your answer.

Does data for eight-year-old twins suggest that height is largely controlled by genetic factors? Explain you answer.

Suggest an explanation for the low concordance at birth for monozygotic twins.

Explain the meaning of each of the following terms:
(i) Variation
(ii) Mutation

Explain how mutation causes variation. Give examples.
Explain how meiosis causes genetic variation in the gametes.

Complete the following table to show the different phenotypes you would expect in the F2 and their ratio.

Phenotype Ratio

State the ratio of phenotypes expected in the F2 offspring.

Mendel’s Second Law of inheritance states that, “during gamete formation the segregation of each gene pair is independent of other pairs.” How do the diagrams above prove this law? (AC 2.4).

Haemophiliacs possess a non-functional form of the gene responsible for the production of blood clotting factors. Shown below is the occurrence of haemophilia in one family.

Using the following symbols:
H = dominant allele h = recessive allele

State the genotypes of the following individuals.
Individual Genotype
1
2
3
5
6
9
2) On the basis of the information provided, is the inheritance of haemophilia:
(i) autosomal or sex-linked?
(ii) dominant or recessive?
State the probability of individual 8 being a carrier of haemophilia.
Explain why only females can be carriers of haemophilia.

Complete the following genetic diagram to show how parents who did not suffer from haemophilia, could have a son with haemophilia but also other children who did not suffer from haemophilia.
Phenotype of parents Genotype of parents Genotype of gametes
Normal male
Normal female

Genotype of offspring
Phenotype of offspring

What is the probability of the couple having a daughter with haemophilia?

What is the probability of the couple having another son with haemophilia?

Who’s gonna take you home tonight?

There has been a mix up in the maternity ward. The babies have managed to remove their wrist bands. On their wrist bands are their blood groups and names.

Billy Smith Blood group:A
Sarah Chadwick Blood group:AB
Imran Ahmed Blood group:B
Johnny Honest Blood group:O

Complete the table to match each parent to their baby by indicating the parental genotypes using the symbols IA, IB, and i, and then the name of the baby that belongs to each set of parents. Consider one blood type might have more than one genotype.

Parental Blood groups Parents Genotype Baby Blood Group
O and O

AB and O

A and O

AB and A

What is meant by epistasis?
The natural colouration of wild mice is called agouti and is produced from banded hairs. Two genes are involved, each with a dominant (A and B) and a recessive allele (a and b). The allele A codes for the ability to produce hair pigment: AA and Aa mice have pigmented hairs but all aa individuals are albinos. The B allele codes for the ability to make hair with grduated colouration: BB and Bb mice have graduated hair, bb mice have hair that is all one colour which is black.

Two agouti mice, genotypes AaBb, are bred together. What phenotypic ratio would you expect in the next generation? Set out the crosses using a Punnett square.

Gametes

Ratio:……………………………………

Discuss which further tests could be conducted to identify these bacteria mentioning using a total of three examples from observational, biochemical and molecular tests. (15 pt).

Medical Micro biology

Answer FOUR of the questions below, each question has a maximum mark of 25 points.

Explain the mechanism of action of penicillin, the mechanism of beta lactamase-mediated resistance and adjuvant-based countermeasures taken in a clinical setting. Further, explain how resistance is achieved in MRSA and why vancomycin can be used as an antibiotic of last resort against most MRSA strains (25 pt).

Have a look at Figure 1. It shows the result of Gram stain.

Describe the picture and the types of bacteria you can see in terms of shape and Gram status (5 pt).

Explain the cellular features Gram staining is based on and why this has an impact on antibiotic treatment of these isolates (5 pt).

Discuss which further tests could be conducted to identify these bacteria mentioning using a total of three examples from observational, biochemical and molecular tests. (15 pt).

Hospital-acquired infection. Name the pathogens of the ESKAPE group and common infections they cause. Describe the cellular pathogenesis and virulence factors of one of these species during an opportunistic infection of human tissue in detail. Link virulence factors to their respective target tissue, cells or organism (25 pt).

Lung pathogens. Outline the pathophysiology of an infection with Mycobacterium tuberculosis. Describe factors that enable Mtb to survive and multiply in host macrophages. Explain why HIV co-infection is commonly associated with worse clinical outcomes of TB (25 pt).

Describe the similarities and differences in transmission to humans of malaria, rabies and the plague. Contrast the pathogens causing these diseases and discuss the suitability of control measure within the context of a OneHealth framework, highlighting success stories and controversies (25 pt).

Compare how genetic information is stored and used in Human Immunodeficiency Virus (HIV), SARS-CoV-2 and Influenzavirus (15 pt).

For infection caused by Influenzavirus, explain the mechanism behind the emergence of potentially pandemic flu strains and contrast this to seasonal flu. Describe the process for seasonal flu vaccine production (5 pt).

Explain why the unique way information is stored in HIV is key to treatment of HIV infections (5 pt).

What specimen is usually collected from patients? Any specific feature, such as spore-forming, strict anaerobic, extreme motility, very fastidious, intracellular bacteria, opportunistic pathogen?

Toxoplasmosis

The microorganism and its characteristics
scientific name of the organism (genus and species)
Gram reaction, shape if applicable
Any specific feature, such as spore-forming, strict anaerobic, extreme motility, very fastidious, intracellular bacteria, opportunistic pathogen?

known virulence factors of this pathogen
toxins? What kind? If exotoxins are made, what do they do?
Spreading Enzymes? What do they do?
Mechanisms to evade host defense?

Describe the disease caused by this pathogen
What are the major clinical symptoms?
Describe the progression of disease.
Are there different forms of the disease? ( such as cutaneous vs intestinal, infant vs adult forms, etc)
Mortality rate if any

Transmission and epidemiology
how is this pathogen transmitted to hosts;
What is its reservoir?
What kind of people are at risk for this disease?
Is it a rare disease? What is the occurrence of this disease in the US if this is a reportable disease?

Disease diagnosis
What specimen is usually collected from patients?
Explain what the test is all about. Bacterial ID culture? Blood test for what? Skin test for what?

How is this disease treated or how are the symptoms managed?

What kind of drugs are used?

Treatments other than drugs?

g) Disease Prevention
any vaccine? Any antitoxin used?

Any preventive methods? ( such as insect repellent, handwashing, etc

 What extent did our class activity support your learning about implicit bias and how it plays a role a STEM and healthcare?

Reflecting on bias research
Write a 250+ word reflection and be sure to address the following points:

What most stood out to you from our class meeting?
What extent did our class activity support your learning about implicit bias and how it plays a role a STEM and healthcare?

Thinking back to your expert and jigsaw groups, what about your group dynamics worked for you? Is there something that might further encourage you to share more with your peers in your groups?

Think about the evolutionary steps needed to separate a flying, endothermic avian from scaled, running reptiles. What evidence did they give for this transition?

Virtual museum visit – evolution in the dinosaur and bird clades

Go to https://www.biointeractive.org/classroom-resources/interactive-assessment-origin-birds and launch the interactive video. As you are watching the video you will need to complete the assessment questions along the way to proceed. Watch the entire video. Think about the evolutionary steps needed to separate a flying, endothermic avian from scaled, running reptiles. What evidence did they give for this transition?

Using the evidence you gathered from the virtual path, you will discuss evolution in the dinosaur and bird clades. You will need to gather 2 outside sources to use, in addition to the AMNH information or HHMI information. These sources must be peer reviewed, scientific journal articles. The sources cannot be older than 20 years (so, 2000-2020 publications), cannot be books or review articles, and cannot be websites. You will paraphrase information from these sources into your own words to construct a valid argument for your thoughts.

How to find and evaluate journal sources. A primary literature source is a peer-reviewed scientific article which details the original research on a topic a group did. This is not a review paper, which synthesizes multiple sources into a single article. It must be on one specific experiment or discovery. You can find peer reviewed articles through library pages (use search engines like ProQuest Biology or the WorldCat general search), or by using Google Scholar. You must limit your search to the past 20 years!

 

In Erminette chickens, one allele produces black feathers (B) and the other produces white feathers (W). Heterozygous individuals have some black feathers and some white feathers, giving them a speckled appearance. If a black rooster and a white hen mate, what would be the ratio of genotypes and phenotypes in the F2 generation?

GENETICS PROBLEM SOLVING
Monohybrid Crosses

Free ear lobes in humans is dominant (F) to attached earlobes (f). Show the cross between two individuals that are heterozygous for free earlobes. Solve by filling out a Punnett square. What will be the probable genotypic and phenotypic ratios of their offspring?
Insert Punnett Square Photo below:

Genotypic Ratio: Click or tap here to enter text.
Phenotypic Ratio: Click or tap here to enter text.

Tongue rolling in humans is a dominant trait (R) to non-rolling (r). If two parents are unable to roll their tongue, what will be the genotypic and phenotypic ratios of their offspring? Solve by filling out a punnett square
Insert Punnett Square Photo below:

Genotypic Ratio: Click or tap here to enter text.
Phenotypic Ratio: Click or tap here to enter text.

Test Cross

An animal breeder wants to know if a black guinea pig is homozygous or heterozygous for coat color. He test crosses the black guinea pig with a homozygous recessive white guinea pig. If one of the offspring is white, what is the genotype of the black parent guinea pig? Click or tap here to enter text.

Pedigree Study

The ability to taste a chemical called PTC (phenolthiocarbimide) is controlled by a dominant gene (T). Use (t) for non-tasters. Shaded individuals cannot taste PTC (non-tasters). Record the genotype for all designated individuals using the table below the pedigree. For unknown dominant phenotype individuals use (T?).

Generation Individual Genotype (1/2 point each)
I. 1. Click or tap here to enter text.

II. 4. Click or tap here to enter text.

II. 5. Click or tap here to enter text.

III. 2. Click or tap here to enter text.

Dihybrid Crosses
If a purebred thorny plant (T) with red flowers (R) were crossed with a plant that was purebred for yellow flowers (r) and no thorns (t), what would be the phenotypic ratio for the F₂ Generation (like the Mendel dihybrid cross for pea shape and color in notes and textbook)?

Insert F₂ Punnett Square Photo below:

F₂ Phenotypic Ratio: Click or tap here to enter text.

In fruit flies long wing is dominant to vestigial (underdeveloped) wing and brown body is dominant to black body. Cross a fruit fly that is homozygous dominant for long wing and heterozygous for brown body with a fruit fly that is heterozygous for brown body and homozygous for vestigial wing.
Insert Punnett Square Photo below:

Phenotypic Ratio: Click or tap here to enter text.

Incomplete Dominance
Snapdragon flowers can be red, white, or pink. Pink flowers result when red and white flowers cross-pollinate. Red snapdragons are homozygous red (RR) and white snapdragons are homozygous white (R’R’). Show the cross between a red snapdragon and a pink snapdragon.
Insert Punnett Square Photo below:

Genotypic Ratio: Click or tap here to enter text.
Phenotypic Ratio: Click or tap here to enter text.

Codominance

In Erminette chickens, one allele produces black feathers (B) and the other produces white feathers (W). Heterozygous individuals have some black feathers and some white feathers, giving them a speckled appearance. If a black rooster and a white hen mate, what would be the ratio of genotypes and phenotypes in the F2 generation?
Insert Punnett Square Photo below:

Genotypic Ratio: Click or tap here to enter text.
Phenotypic Ratio: Click or tap here to enter text.

Blood Typing
A man with type A+ blood and a woman with type B+ blood have a baby with type O- blood. Be sure to include Rh factor (+/-). Determine the genotype for each:
Man = A+: Click or tap here to enter text.
Woman = B+: Click or tap here to enter text.
Baby =O-: Click or tap here to enter text.

There is a mix up at the hospital between parents and babies. As the administrator in charge, you MUST send the correct baby home with it proper parents. Match proper parents with their baby.

Baby R is A+
Baby S is B+
Baby T is B-
Baby U is O-

Proper Match:
Parents #1 are blood type AB- and O- Baby: Click or tap here to enter text.

Parents #2 are blood type A- and B- Baby: Click or tap here to enter text.

Sex-linked
11. Hemophilia in humans is caused by a recessive mutation on the X-chromosome. What will be the outcome (genotypic and phenotypic ratio) of mating between a homozygous normal female (XHXH) and a hemophilic male (XhY)? See lecture notes for proper recording of ratios for each sex.
Insert Punnett Square Photo below:

Genotypic Ratio: Click or tap here to enter text.
Phenotypic Ratio: Click or tap here to enter text.