Scientific Method and Biology: Key Concepts Explained
The Scientific Method
The scientific method is a process used across all sciences. The steps include:
- Observation of events
- Formulation of a hypothesis
- Corroboration of hypotheses through testing
- Development of a theory
Scientific Knowledge
Scientific knowledge is limited to what can be perceived directly by the senses or through instruments that amplify the senses.
Biology: The Study of Life
Biology is the science that studies living organisms. Fields of study include:
- Descriptive or Structural Biology:
Cell Biology, Evolution, and Primordial Earth: Key Concepts
Cell Division and Processes
Interphase (I): Distinct nucleus, normal cell functions.
Prophase (P): Nuclear membrane breaks down, chromosomes condense, spindles form.
Metaphase (M): Chromosomes line up across the equator of the cell.
Anaphase (A): Chromatids migrate to poles.
Telophase (T): Two new nuclei form, chromosomes decondense.
Cytokinesis (C): Cytoplasm divides, resulting in two new cells.
Translation
- mRNA binds to ribosome.
- mRNA advances until AUG (start codon) is at the P site.
- tRNA binds to codon
The Human Nervous System: Structure and Function
Central Nervous System
The central nervous system (CNS) is formed by the brain and spinal cord. It is responsible for processing received information and controlling body functions.
Peripheral Nervous System
The peripheral nervous system (PNS) is formed by a set of nerves that connect the CNS with the rest of our body organs. Its function is to transmit information and conduct the CNS’s orders to the organs responsible for executing them.
Brain
The brain is located in the skull. It consists of the cerebrum,
Read MoreGenetics: Key Concepts and Heredity Principles
Gene: A gene is the basic unit of heredity, transmitting genetic information.
Genotype: The complete set of genes within an individual.
Phenotype: The observable characteristics of an individual, resulting from the interaction of genotype and environment.
Homozygous: Having two identical alleles for a particular gene.
Heterozygous: Having two different alleles for a particular gene.
Dominant Allele: An allele that expresses its trait even when paired with a recessive allele.
Recessive Allele: An allele
Read MoreImmune System Defenses: Types and Processes
Nonspecific Defenses
The immune system employs various nonspecific defenses to protect the body from pathogens.
Phagocytes
Phagocytes are leukocytes responsible for removing microorganisms and foreign substances from tissues through phagocytosis.
Phagocytes move via amoeboid movements.
Types of Phagocytes
- Granulocytes: These cells contain abundant granules with enzymes and antimicrobial compounds.
- Monocytes: These cells lack granules and have a lobulated nucleus. They are larger than granulocytes.
Phagocytic
Read MoreAnimal Breeding and Genetics: Concepts and Applications
True/False Questions in Animal Breeding and Genetics
General Concepts
1. Animal domestication processes are exclusively based on artificial selection (False)
2. All quantitative traits present more than 20 phenotypic classes (False)
3. Highly inbred lines can be used to analyze the environmental contribution to a given trait (True)
4. The breeding value of an animal is always constant, independently of the environment (False)
5. The breeding value of the offspring of an individual can be half of its breeding