Module 1: Introduction to Biology Flashcards
What are the 10 steps of the scientific method?
- Observation
- Question
- Hypothesis
- Null hypothesis
- Prediction
- Methods (includes establishing a control)
- Results
- Discussion
- Conclusions
- Future work
What are the 6 characteristics that distinguish living from non-living things?
- They have a structure that is ordered (they are not just random collections of matter).
- They can reproduce.
- They can grow and develop.
- They can maintain a consistent internal environment (Homeostasis).
- They can respond to changes in the environment (through long-term evolutionary or short-term environmental changes).
- They require energy.
Robert Hook
Anton van Leeuwenhoek
Robert Brown
MJ Schleiden
Theodor Schwann
Robert Hook: English scientist who first penned the term “cells.”
-His microscopes used light and 2 lenses.
Anton van Leeuwenhoek: Dutch lens maker who was the first person to describe bacteria.
-His microscopes used light and 1 lens.
Robert Brown: Scottish botanist who was the first to describe a cell’s nucleus.
MJ Schleiden: German scientist who described the nucleus as the most important part of plant cells.
Theodor Schwann: German scientist who published the “Cell Theory.”
What are the 3 basic ideas of the Cell Theory?
- All living organisms are made up of one or more cells.
- The cell is the basic organizational unit of life.
- All cells come from other cells.
Organism
A living entity made up on one or more cells.
Which 3 ideas laid the groundwork for modern biology?
- The cell theory
- The theory of evolution
- The chromosome theory of inheritance
Theory
An explanation for a very general class of phenomena or observations that is supported by a wide body of evidence.
Null hypothesis
Specifies what the results of an experiment will be if the main hypothesis being tested is wrong.
Often states that there will be no difference between experimental groups.
Rudolf Virchow
German scientist who proposed that all cells arise from cells already in existence.
Spontaneous generation
Prior to the cell theory, the explanation that cells could arise spontaneously under certain conditions.
Hypothesis
A testable statement to explain a phenomenon or a set of observations.
A theory serves as a framework for developing new hypotheses.
Experimental prediction
Describes a measurable or observable result that must be correct if a hypothesis is valid.
Louis Pasteur
French scientist who used experiments to test the cell theory.
His experiment proved the all-cells-from-cells hypothesis.
Chemical evolution
The theory that simple chemical compounds in the early atmosphere and ocean combined to form larger, more complex substances, eventually leading to the origin of life and the start of biological evolution.
Who originally formulated the idea that all distinct, identifiable types of organisms are connected by common ancestry?
Charles Darwin and Alfred Russel Wallace (1959)
Theory of Evolution by Natural Selection
The theory that similarities among types of organisms are mostly due to the fact that they are related to one another.
It was developed over a 20-year period.
What are the two claims of Darwin & Wallace’s theory concerning patterns that exist in the natural world?
- Species are related by common ancestry.
- The characteristics of species can be modified from generation to generation (“descent with modification”).
Evolution
A change in the characteristics of a population over time.
Population
A group of individuals of the same species living in the same area at the same time.
Natural selection
The process by which individuals with certain heritable traits tend to produce more offspring than individuals without those traits.
Often leads to a change in the genetic makeup of a population.
Natural selection occurs whenever which two characteristics are met?
- Individuals within a population vary in characteristics that are heritable (can be passed onto an offspring).
- In a particular environment, certain versions of these heritable traits help individuals survive better or reproduce more than other versions.
Natural selection acts on _________ but evolutionary change occurs in _________.
Natural selection acts on individuals but evolutionary change occurs in populations.
Speciation
The evolution of two or more distinct species from a single ancestral species.
When populations of one species diverge and form new species.
Fitness (in biology)
An individual’s ability to produce viable offspring.
Adaptation (in biology)
A trait that increases the fitness of an individual in a particular environment.
The chromosome theory of inheritance
The principle that genes are located on chromosomes and that patterns of inheritance are determined by the behaviour of chromosomes during meiosis.
Chromosome
Gene-carrying structure consisting of a single long molecule of double-stranded DNA and associated proteins.
Inside cells, hereditary or genetic information is encoded on ___________, the units located on ___________.
A chromosome consists of a molecule of ___________.
Inside cells, hereditary or genetic information is encoded on genes, the units located on chromosomes.
A chromosome consists of a molecule of DNA.
Central dogma
The scheme for information flow in the cell:
DNA»_space; RNA»_space; protein.
First penned by Francis Crick.
Deoxyribonucleic acid (DNA)
A nucleic acid that carries genetic information.
Generally occurs as a double helix with two intertwined strands held together by non-covalent bonds.
Ribonucleic acid (RNA)
A usually single stranded nucleic acid that transports messages of the DNA code required for protein synthesis (mRNA).
What are the 2 fundamental nutritional needs of organisms?
- Acquiring chemical energy in the form of ATP.
- Obtaining molecules that can be used for the synthesis of complex compounds such as DNA, proteins, etc.
Tree of life
A family tree of all organisms.
Carl Wose
An American biologist who analyzed the molecular components of organisms as a way to understand their phylogeny.
Phylogeny
The evolutionary history of a group of organisms.
Translates to “tribe-source”
Ribosomal RNA (rRNA)
An RNA molecule that forms part of the ribosome.
Ribonucleotides
The 4 smaller chemical components of an rRNA molecule.
They are symbolized by the letters A, U, C, and G.
What are the nucleobases of DNA?
What are the nucleobases of RNA?
DNA: Thymine - Adenine, Cytosine - Guanine.
RNA: Uracil - Adenine, Cytosine - Guanine.
Phylogenetic tree
A branching diagram that shows the evolutionary relationships among species.
Last universal common ancestor of cells (LUCA)
A theoretical entity proposed to be the product of chemical evolution and provided characteristics of life that are shared by all living organisms on earth today.
What are the 3 fundamental groups or lineages of organisms established by the tree of life?
[Prokaryotes]
1. The Bacteria
2. The Archaea
[Eukaryote]
3. The Eukarya