Unit 1 Review
What are the advantages of being asexual?
- Do not rely on another organism. - Reproduction can happen faster. - Downside: offspring are identical to the parent, lack of variation and evolution
What are the advantages of being sexual?
- More variation in the species, and greater chance for adaptation and survival
Complex Viruses (bacteriophages)
-Capsid (head) is polyhedral, tail sheath is helical -Tail fibers, plat and pin -Injects its genetic material into the host cell
Nucleus
-Function: control center of cell. protects DNA. instructions for building proteins -Structure: Membrane bound organelle
Lysosomes
-Function: digest food. used to make energy. clean up & recycle. digest broken organelles -Structure:membrane sac of digestive enzymes
Golgi Apparatus
-Function: finishes, sorts, labels & ships proteins. ships proteins in vesicles (like UPS headquarters, shipping & receiving department, "UPS trucks") -Structure: membrane sacs
Centrioles
-Function: help coordinate cell division ***only in animal cells -Structure: one pair in each cell
Rough Endoplasmic Reticulum
-Function: helps complete the proteins after ribosome builds them -Structure: ribosomes attached
Cytoplasm
-Function: holds/contains the organelles -Structure: viscous fluid
Mitochondria
-Function: make ATP energy from cellular respiration. fuels the work of life ~C6H12O6+ O2 → CO2 + H2O+ATP -Structure: double membrane
Chloroplast
-Function: make energy + sugar from sunlight using photosynthesis -Structure: double membrane found only in plant and algae ~sunlight + CO2 → ATP & sugar
Smooth Endoplasmic Reticulum
-Function: makes lipids and breaks down toxic substances -Structure: No ribosomes attached
Nucleolus
-Function: makes ribosomes -Structure: found inside nucleus
Cell Wall
-Function: outside cell membrane; extra protection for plants ad bacteria -Structure: a rigid layer of polysaccharides:made of chitin (fungi) or cellulose (plants)
Ribosome
-Function: site of protein synthesis -Structure: non-membrane bound organelle -Two types: free floating and fixed; Made up of two subunits, one large and one small
Vacuoles
-Function: storage -Structure: membrane sac -Plants have one large one
Cytoskeleton
-Function:provides structural support. aids in movement of the cell and within the cell (amoeba) -Structure: Composed of a network of protein fibers
Helical Viruses
-Long Rod shaped -Flexible or rigid -Viral Genome found inside a hollow cylindrical capsid -Examples: Ebola virus and Rabies virus
Polyhedral Virus
-Many-sided Capsid is in the shape of icosahedron (a polyhedral with 20 triangular faces.) -Examples: Adenovirus, HIV and Poliovirus
Growth (ex: making proteins and making new cells)
-Ribosomes create proteins -Nucleus contains genetic information and make a new cell -The Rough ER made changes to the proteins. -Golgi body modifies and ships proteins -Vesicles take ribosomes and place them where they need to be
Enveloped Viruses
-Roughly spherical -Enveloped helical or enveloped polyhedral viruses. -Enveloped helical= Influenza Virus -Enveloped polyhedral= Herpes simplex virus
Cell Membrane
-Separates cell from outside. -Controls what enters or leaves cell. -Structure: double layer of fat. -Also known as phospholipid bilayer. -ex:O2, CO2, food, H2O, nutrients, waste
DNA
-Structure: Long tangled strands of genetic material (DNA) found in the nucleus -Function: contain the instructions for making proteins
Cilia
-Structure: Short, hair-like projections from cell, -Function: aid in movement ~In humans, motile cilia are found in the lining of the trachea (windpipe), where they sweep mucus and dirt out of the lungs. In female mammals, the beating of cilia in the Fallopian tubes moves the ovum from the ovary to the uterus.
Flagella
-Structure: Tail like projections from cell, ~whip-like motion to propel the cell forward ~In humans, sperm have a flagella to help it swim to find the egg (ovum) -Functions: Structures that aid in locomotion or movement of other substances or objects
Metabolism (using energy)
-The mitochondria because it creates energy and ATP -The cell membrane allows sugars to come in
Homeostasis (maintaining a stable internal environment)
-The mitochondria in a cell crates energy and ATP to maintain homeostasis -The cell membrane lets sugar come in and out -Lysosomes breaks down waste -Nucleus dictates what happens
Cellular control-Protein Synthesis
-These organelles are involved with "controlling" the cell and protein synthesis -Remember proteins do the "work" of the well
Lytic Cycle- Virion Release
• New Infectious Virions are Release from the host cell - Lyses the Cell in the Lytic Cycle - New viruses assemble and are released from host cell after being enveloped by host's modified plasma membrane.
Response to the Environment
• Organisms' environments are always changing. • It is important for living things to adapt to their environment to survive. • What are some responses that you already know?
Plant Responses
• Phototropism • Gravitotropism/Geotropism • Thigmotropism
What types of human cells does the malaria parasite, Plasmodium falciparum, infect?
• Red blood cells
Made up of cells
• Smallest unit of an organism that can be considered alive. • Some organisms can be unicellular (made of only one cell), and others can be multicellular. • Each of the trillions of cells in our body is considered living and so are we.
What happens in a blood sample of individuals who carry the sickle cell allele when the blood is deprived of oxygen?
• Some red blood cells change shape, or sickle, when deprived of oxygen.
What were Dr. Allison's initial observations?
• That there was a high frequency of people carrying the sickle cell allele, or character, in the coastal areas and near Lake Victoria but a lower frequency in the highlands
How does the sickle cell allele protect against malaria?
• The allele compromises the ability of the parasite to reproduce.
What did Dr. Allison hypothesize after his 1949 expedition?
• The sickle cell allele (or character) protects against malaria.
The 7 characteristics of life
1. Made of cells 2. Can grow and develop 3. Ability to reproduce 4. Evolving and Adapting 5. has a need for energy- metabolism 6. Maintains homeostasis 7. Responds to stimulus from environment
Lytic Cycle
1. The Virion attaches & enters host cell 2. Releases the viral genome into host cell 3. Host Cell Machinery: -Replicated Viral DNA -Makes viral proteins 4. New Viral DNA and Protein self assemble into progeny Virions 5. Infectious Virions are related to find new host cell
Lysogenic
1. The Virion attaches & enters host cell 2. Releases the viral genome into host cell DETOUR: Viral Genome integrates into host genome and lies dormant 3. Host Cell Machinery: -Replicated Viral DNA -Makes viral proteins 4. New Viral DNA and Protein self assemble into progeny Virions 5. Infectious Virions are related to find new host cell
Viral Entry
1. Virus enters cell straight through cell mem. 2. Virus injects DNA/RNA into cell (Bacteriophage) 3. Virus is brought into the cell in an endosome or vesicle through endocytosis 4. Viral Envelope binds with the host cell membrane
Schwann
A scientist who concluded that all animals are composed of cells
Schleiden
A scientist who concluded that all plants are composed of cells
Hooke
A scientist who observes that cork was composed of tiny, hollow boxes that he called cells
Cell Theory
Claims that all living tis are composed of cells. Cells are the basic unit of living things, and that all cells come from cells
Eukaryotes
Examples: -Multicellular- plant and animal cells. -Unicellular- yeast and protist -Organelle present (Organelles=membrane bound structures) -DNA is found in nucleus. -Chemical reactions occur in specific organelle -multi-celled or uni-celled
Prokaryotes
Examples: rod-shaped bacterium and Bacillus coaguains - NO membrane bound organelles -DNA is circular and not in the nucleus -All chemical reactions occur in the cytoplasm
Vesicles
Function: moving material around cell. Structure: membrane sac
Plants make energy two ways!
Mitochondria -make energy from sugar + O2 ~cellular respiration ~sugar + O2 → ATP Chloroplasts -make energy + sugar from sunlight ~photosynthesis ~sunlight + CO2 → ATP & sugar
Viral Structures
Helical Virus, Polyhedral viruses, Enveloped viruses, Complex viruses (bacteriophages)
2. Why are there higher frequencies of the sickle cell allele in areas where malaria is more prevalent?
In areas where malaria is endemic, the presence of the sickle cell allele in the heterozygous state improves the fitness of individuals. These individuals are provided some protection from malaria and are therefore more likely to survive and reproduce than those who do not carry the sickle cell allele.
Spotaneous Generation
Living things come from non living things
3. Define "natural selection" and explain how Dr. Allison's work provides an example of natural selection in humans.
Natural selection is a process by which organisms most suited to their environment survive and reproduce at higher rates. Dr. Allison provides evidence that shows that, while the sickle cell allele is advantageous in one environment, it is not in another. In an environment where malaria is endemic, individuals who carry the sickle cell allele have a selective advantage because they are protected against malaria. In an environment like the coastal regions of East Africa or near Lake Victoria, Dr. Allison shows that natural selection favors an increased frequency of the sickle cell allele. However, in an environment where malaria is not endemic, like in the East African highlands, the sickle cell allele is disadvantageous. Individuals who are heterozygous (AS) for the sickle cell allele have no selective advantage in this environment, and two heterozygous individuals can pass on their sickle cell allele to their offspring, who inherit sickle cell anemia. Since sickle cell anemia can be a lethal disease, for every child with sickle cell disease, two sickle cell alleles are eliminated from the population.
Two Major Cell Types
Prokaryotes and Eukaryotes
Capsomere
Protein Subunits that make up the capsid
Capsid
Protein coat that encloses the viral genome and helps in host cell recognition
Nucleic Acid
genetic material; either DNA or RNA
Virchow
The first scientist suggest that cells come from pre-existing cells
Leeuwenhoek
The first scientist to describe living cells as seen through a microscope
Need for Energy - Metabolism
• Must have a source of food (sugar) to ultimately make energy for life processes. - Autotrophs: make their own food (plants) - Heterotrophs: must consume their food. (animals) • Cellular respiration give animals energy and photosynthesis give plants energy
Protein Assembly and transport
These organelles are involved with assembling and finalizing the proteins that were made in the other organelles
Energy Transformers
These organelles are involved with changing food energy to a form the cell can actually use
Cell movement
These organelles are involved with helping the cell move or aiding in materials moving throughout the body
Cellular Storage and Recycling
These organelles are involved with storing molecules the cell needs and getting rid of waste
Cell Boundary
These organelles keep the cell protected. They also allow substances to leave and enter the cell as need. (ex: Cell Membrane and Cell Wall)
Cellular Structure
These organelles support the cell ad helps keep its shape
Nucleocapsid
combo of genetic info + capsid
Viron
complete infectious virus particle. Most contain: a capsid, capsomere, nucleic acid, and nucleocapsid. Some contain: envelope
Biogensis
living cells come from preexisting cells
Envelope
membrane of proteins and glycoproteins surrounding the nucleocapsid
What is sickle cell disease (or sickle cell anemia)
• A genetic disease • A painful, potentially fatal disease • A disease that prevents oxygen from getting to all parts of the body • A disease caused by a mutation in the hemoglobin gene
Reproduction
• Asexual: without sex, one parent - Examples are budding, binary fission, and regeneration • Sexual: requires sperm and egg, two parents - Examples: sperm/egg; pollen/egg
Passing on genetic code, adapting and evolving
• Genetic code determines the inherited traits of every organism on earth. • Rarely, mistakes in genetic code lead to evolution, a positive change in an population's DNA that increases it's chance for survival • All living things have DNA or RNA, their genetic code
Growth and Development
• Growth: An increase in size, mass, or complexity.
What data did Dr. Allison collect to test his hypothesis?
• He collected blood samples from 5,000 children in all parts of East Africa. • From the blood samples, he looked at the malaria parasite load and tested whether the children had the sickle cell character.
What were Dr. Allison's initial questions when he went to East Africa in 1949?
• He wanted to know the distribution of the ABO blood groups and other inherited characteristics, including the sickle cell allele, in East African tribes.
Maintaining Homeostasis
• Homeostasis: the process by which organisms keep their internal conditions relatively stable (the same). - Ex: Temperature, pH, water concentration
Where is malaria most prevalent in East Africa?
• In the coastal areas and around Lake Victoria
Where is the sickle cell allele, or "character," most common in East Africa?
• In the coastal areas and around Lake Victoria
How is malaria transmitted?
• It is transmitted by mosquitoes. • When mosquitoes carrying the parasite (Plasmodium falciparum) bite an uninfected person, they can transmit malaria. • Mosquitoes become infected with malaria when they bite a person infected with malaria (not shown in the film).
1. Dr. Allison's hypothesis was supported by the data he collected.
• There were many more children with the sickle cell allele in regions of East Africa where malaria was endemic than there were in the arid and highland areas. • The parasite load was lower in the red blood cells of children with the sickle cell allele than in those without it. • In arid and highland areas of East Africa, the frequency of children with the sickle cell allele was much lower than in coastal and wetland regions. • Other areas of the world where malaria is endemic also show an elevated frequency of the sickle cell allele.
Production of Viral Parts
• Viral DNA is replicated and transcribed into RNA (transcription) by host machinery • Viral RNA is translated (Translation) by host machinery (ribosomes) to make the Viral Protein
Release of DNA/RNA
• Viral genome can be single or double stranded • Can be DNA or RNA • Enters cytoplasm and makes it way to the host nucleus • DNA can be used for Transcription or Translation (Lytic Cycle) OR • DNA can integrate into the host genome and go dormant (Lysogenic Cycle)