Notes, summaries, assignments, exams, and problems for Baccalaureate

c) Antigen Processing and Presentation

• Engulf protein antigens, partially digest them, and display polypeptide fragments on the surface for T cells to "see."
• Fragments are associated on the surface with Major Histocompatibility Antigens (MHC II), which are necessary to activate T cells.

d) Dendritic Cell Migration

To increase the chance of interacting with the correct T cells, dendritic cells migrate to secondary lymphoid organs (chemokines are secreted to attract T cells).

VII. Extracellular Killing by the Immune System

A. Natural Killer (NK) Cells

NK cells lyse virus-infected cells, tumor cells, and parasites. They kill cells that do not express MHC class I antigens.

B. Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC)

1. In ADCC, NK cells and macrophages

Dominando Verbos Frasales Esenciales

Los verbos frasales son combinaciones de un verbo y una preposición o adverbio, que juntos adquieren un significado diferente al de sus palabras individuales. Aquí tienes una lista de verbos frasales comunes con su significado en español:

• Break up: Romper con alguien
• Fall out: Caerse (o discutir con alguien)
• Get on with: Llevarse bien con alguien
• Get over: Recuperarse de un bache o superar algo
• Get together: Reunirse
• Make up: Maquillarse (o reconciliarse)
• Stand up: Levantarse
• Take after: Parecerse (mentalmente o en personalidad)
• Dress up: Disfrazarse o vestirse elegantemente
• Pay for: Pagar por algo
• Put on: Ponerse (ropa, etc.)
• Take off: Quitarse (ropa, etc.)
• Try on: Probarse (ropa)
• Break into: Entrar a la fuerza
• Log

Mitosis and Meiosis Comparison

Similarities Between Mitosis and Meiosis

• The sequence of changes in the nucleus and cytoplasm.
• The presence of the stages of prophase, metaphase, anaphase, and telophase.
• The spindle formation and the cycle of condensation of chromosomes.

Key Differences Between Mitosis and Meiosis

• Mitosis occurs in somatic cells, while meiosis is restricted to germ cells.
• In mitosis, each cycle of DNA replication is followed by one division. The resulting daughter cells are diploid (2n) and have the same amount of DNA as the parent cell.
• In meiosis, one DNA replication cycle is followed by two divisions, resulting in four haploid (n) daughter cells, which contain half the DNA of the parent cell.
• In mitosis, each chromosome behaves independently.

Hume's Science of Man: Foundation and Purpose

David Hume defends the dependence of all sciences on the science of man, or the science of human nature. It is man who comprehends these sciences, which are his own creation, and it is man who must be studied. This Science of Man aims to guide society toward a world free of prejudice and religious bigotry, moving away from ancient and superstitious beliefs.

Critique of Superstition and Metaphysics

Hume, a profound rationalist, believes that rationalist superstition and metaphysics form the ideological basis of societal shortcomings. Religious intolerance, hypocrisy, and malice impede the progress, culture, and welfare of society. The Science of Man, Hume argues, intends to liberate humanity and dismantle... Continue reading "David Hume's Philosophy: Empiricism, Reason, and Human Nature" »

Mobile Phones

Comprehension (4 points)

1. 1) No, because dangerous effects have not been shown conclusively.
2. 2) Because they used the phone while they were driving.

1. 3) True… advanced features are packed into extremely light and tiny models (lines 5-6).
2. 4) True… mobile phones can be a serious threat to health, for children in particular (line 7).
3. 5) False… what for many people is a useful device can be a nuisance for others (line 11).
4. 6) False. Some people even claim that… (lines 12-13).

Use of English (3 points)

1. 7) Luxury (l.1)
2. 8) Light (l. 6)
3. 9) Sickness, illness, disease
4. 10) Headache, backache, stomach-ache… toothache, heartache
5. 11) She said: “We’ll go and get some food.”
   She said they/we would go and get some food.
6. 12) I asked my father to

English Vocabulary Acquisition

How Children Learn Word Meaning

Children are always acquiring and building up their L1. They must find out which things can be packaged together under a label.

Knowing a Word: Types of Knowledge

Knowing a word involves different types of knowledge. The importance is how it is pronounced.

Factors Affecting Vocabulary Learning

• Demonstrability: Can the meaning be easily shown? (e.g., car = transport)
• Similarity: Is it similar to known words? (e.g., equal)
• Brevity: Is it a short or long word?
• Regularity of Form / Learning Load: Does it follow typical patterns? (e.g., bedroom)
• Opportunism: Is the word relevant to the child's immediate situation?
• Centres of Interest: Are words likely to be of relevance to the child's interests?

1. "I can't come to the party now," said Lucy. (apologise)
   Lucy apologised for not being able to come to the party then.

2. "We went to the concert yesterday," said my brother. (say)
   My brother said they had gone to the concert the day before.

3. "Will you help me with this project?" she asked. (ask)
   She asked me if I would help her with that project.

4. "Where did you buy this jacket?" he asked me. (ask)
   He asked me where I had bought that jacket.

5. "Don't touch that button!" the technician said. (warn)
   The technician warned me not to touch that button.

6. "I forgot to do my homework," said Daniel. (admit)
   Daniel admitted

Microbiology Lab Practice Questions

What is the optimal temperature range for Bacillus stearothermophilus?

Answer: 55°C (a thermophile)

Which organism produces red pigment at 25°C?

Answer: Serratia marcescens

What does no pigment but visible turbidity in S. marcescens at 37°C suggest?

Answer: Growth occurred, but pigment production is temperature-sensitive.

What is the term for bacteria that grow best at cold temperatures but also at room temperature?

Answer: Psychrotroph (e.g., Pseudomonas fluorescens)

What color does E. coli appear on MacConkey agar?

Answer: Pink (lactose fermenter)

Which test detects mixed acid fermentation?

Answer: Methyl Red (MR) test

What does a black precipitate on HE agar indicate?

Answer: H₂S production (e.g., Salmonella)

Which

Cash Flow Statement Fundamentals

Operating Activities (Indirect Method Adjustments)

The calculation starts with the Income Statement components:

• Non-cash expenses (e.g., Depreciation) are typically positive adjustments.
• Losses are generally positive adjustments (added back).
• Gains are generally negative adjustments (subtracted).

Balance Sheet Adjustments (Working Capital Changes)

These adjustments relate to changes in current assets and liabilities:

• Current Assets (e.g., Accounts Receivable, Inventory):
  • Increase in asset balance = Cash Outflow (–)
  • Decrease in asset balance = Cash Inflow (+)
• Current Liabilities (e.g., Accounts Payable):

  Note: Accounts Payable reverses the asset logic.

  • Increase in liability balance = Cash Inflow (+)
  • Decrease in liability