Notes, summaries, assignments, exams, and exercises for Biology for University

Commensalism: One species benefits, while the other is neither helped nor harmed (e.g., microbes living on skin secretions, ear, or external genitals).

Mutualism: Both organisms benefit (e.g., E. coli in the large intestine synthesizing Vitamin K and B/G vitamins).

Symbiosis: Two species living together for mutual benefit (e.g., normal microbiota and host).

Parasitism: One organism (parasite) benefits at the host's expense; includes all disease-producing pathogens.

Opportunistic Microbes: Organisms (resident or transient) that ordinarily do not cause disease, but take advantage of compromised host defenses, failure of immune barriers, or normal flora disturbances.

Resident Microbiota:...

Constructing Recombinant DNA

The following steps are involved in the construction of recombinant DNA:

1. Preparation of the Gene: Gene cloning in bacteria is achieved by cleaving DNA with enzymes called restriction endonucleases, which create small fragments. Each fragment often has a "sticky end." Since eukaryotic genes contain introns that are not processed in bacteria, the DNA for cloning is usually obtained from relevant mRNA through the process of reverse transcription. In cases where nucleotide or amino acid sequences are known, synthetic DNA may also be produced.
2. Insertion into a Vector: The vector is a vehicle, such as a plasmid or bacteriophage, used to transfer DNA into a host cell. The vector is cut with the same restriction endonuclease

1. Know the functions of the lymphatic system

· Produce, maintain, and distribute lymphocytes and other lymphoid cells that provide defense against infections and foreign substances PRIMARY FUNCTION. Return of excess fluid to bloodstream. Transport of lipids absorbed in digestive tract

2. Know the three subtypes of lymphocytes and what type of immunity each is responsible for

· T cells à Cell-mediated immunity (4+ subtypes)

• Cytotoxic T Cells (T_c) - direct cellular attack
• Helper T Cells (T_H) and Suppressor T Cells (T_S) - regulatory roles
• Memory T Cells.

B Cells à Antibody-mediated immunity

• Antibodies (immunoglobulins)
• Antigen - usually proteins (specific chemical targets)

· NK Cells à Immunological surveillance

3. Know where the three types of lymphocytes

Biology and Genetics Practice Questions

78. Sequence of Events in Translation

Which of the following options most accurately lists the sequence of events in translation?

C) codon recognition → peptide bond formation → translocation → termination

79. Definition of Mutation

Any change in the nucleotide sequence of DNA is called

A) a mutation.

80. HIV Virus Type

What kind of virus is HIV?

C) a retrovirus

81. HIV Enzyme for DNA Synthesis

Which of the following enzymes does HIV use to synthesize DNA on an RNA template?

D) reverse transcriptase

82. Griffith's Experiment and DNA Transfer

In the 1920s, Frederick Griffith conducted an experiment in which he mixed the dead cells of a bacterial strain that can cause pneumonia with live cells of a bacterial strain...

Evolutionary Biology Fundamentals

Charles Darwin and the Voyage of the Beagle

Charles Darwin, born in 1809, conducted the Voyage of the Beagle (1831–1836), which led to his foundational observations on biological diversity.

Microevolution vs. Macroevolution

• Microevolution: Changes in a single gene within a population over time.
• Macroevolution: The formation of new species or groups of related species.

Genetics and Inheritance

• Phenotype: The physical expression of an organism’s genes.
• Genotype: The two copies (alleles) of a gene an individual possesses.
• Inheritance: Each individual has two copies of each gene (one from each parent).
• Alleles: Can be dominant or recessive.
• Heterozygous: Individuals with one dominant and one recessive allele (carriers)

Chemical Processes and Molecular Interactions

Dehydration synthesis: Loss of a water molecule between each pair of monomers.

Hydrolysis: Addition of water between each pair of monomers.

Reducing Sugars and Detergents

What is a reducing sugar?

The ability to add electrons to (reduce) other molecules.

What is the function of detergent?

To lower the surface tension of a liquid.

Emulsions and Emulsifiers

• Emulsion: A mixture of two liquids, each insoluble in the other.
• Emulsifier: A substance that stabilizes an emulsion by increasing its kinetic stability.

Cell Structure and Function

Cellular Components and Identification

1. Know the structures of animal and plant cells and their functions.
2. Be able to identify the nucleus, cytoplasm, and cell membrane of an animal

Major Arteries of the Human Body

• Aorta: Extends from the left ventricle of the heart down to the abdomen.
• Carotid Artery: Located on the left and right sides of the neck.
• Subclavian Artery: Positioned underneath the clavicle.
• Pulmonary Artery: Located at the base of the heart's right ventricle.
• Coronary Artery: Supplies the heart muscle.
• Axillary Artery: Located in the armpit region.
• Brachial Artery: Located in the forearm.
• Posterior Tibial Artery: Located behind the tibia.

The Lymphatic System

The lymphatic system is responsible for the removal of interstitial fluid from tissues, the absorption and transport of fatty acids and fats (as chyle) from the digestive system, and the transport of white blood cells to and from lymph nodes and bones.

Lymphatic

Levels of Biological Organization

• Atom: The smallest component of chemical elements that make up living things (bioelements), primarily Carbon (C), Oxygen (O), Hydrogen (H), Nitrogen (N), Phosphorus (P), Sulfur (S), Calcium (Ca), Magnesium (Mg), and Sodium (Na).
• Molecule: A group of two or more atoms joined together chemically.
• Organelles: A group of biomolecules that work together to form cell structures, such as membranes, ribosomes, and mitochondria.
• Cell: A group of organelles and structures. A cell is the simplest level of life.
• Tissue: A group of specialized cells that work together to perform a specific function.
• Organ: A group of different tissues that work together to carry out a specific function.
• Organ System: A group of similar or different

Antigen-antibody reactions

Ag + Ab AgAb

←

·reversible reaction as there are formed noncovalently biochemical bonds

·strength of such interactions is called affinity

·different immunoglobulins within an individual show a wide range of affinity

·valence - number of epitope-binding sites of one immunoglobulin molecule

·avidity - describes the collective affinity of multiple binding sites (affinity + valence)

·e.g. although IgM has a low affinity, its avidity is quite high due to 10 epitope-binding sites

·...

Primary and secondary immune response

·primary immune response

ofirst contact to a foreign antigen that has to be eliminated from the body

ofirst a lag/induction phase (ca. 7-9 days or even up to months) occurs in which no antibody is produced,...

The Role of the Placenta in Mammals

The placenta is the organ from which our group of mammals takes its name: it is the main reason we, the placental mammals, are so much more successful than other mammals. The placenta is composed of several layers of material. It is very richly supplied with blood vessels. In this way, white blood cells and other immune system components are kept within the boundaries of their own systems while nutrients are allowed to pass in, and waste products to pass out, of the embryo's environment. There are at least five different forms the placenta can take in different species of mammals.

Blood Composition and Components

Plasma is the liquid component of the blood. It contains nutrients, wastes, salts, and proteins....