Grade 11 Biology Exam prep Flashcards
The enzymes of the digestive system including where they are produced, where it takes action including the action they complete.
Proteases - breaks down protein into amino acids (found in the pancreas)
Amylase - Breaks down Starch - further breakdown of polysaccharides into maltose disaccharides (found in mouth and pancreas)
Lipase – breakdown of fats into glycerol & 3 fatty acids (found in the pancreas)
Compare and contrast arteries vs veins
Arteries carry blood away from the heart to the tissues, and Blood returns from the capillaries towards the heart through blood vessels called veins.
Arteries
- Carry oxygenated blood from the heart
- Blood flows under higher pressure
- Valves are absent
Arteries have thick walls with muscle and elastic fibres
- The pulmonary artery carries deoxygenated blood from the heart to the lungs
- Carbon dioxide levels in the blood are low
Veins
- Carry deoxygenated blood to the heart
- Blood flows under low pressure
- Valves are present to prevent backward flow of blood
- Veins are thin-walled with less elastic and muscle tissue
- Pulmonary veins carry oxygenated blood from lungs to the heart.
- Carbon dioxide levels in the blood are high
Compare and contrast lytic cycle to lysogenic cycle.
Virus replication involves the processes by which a virus produces new viral particles within a host cell. There are two main types of virus replication: the lytic cycle and the lysogenic cycle.
Lytic Cycle - Short Cycle:
In the lytic cycle, the virus infects a host cell and hijacks the cell’s machinery to rapidly replicate and produce new viral particles.
The steps of the lytic cycle include attachment and entry of the virus into the host cell, synthesis of viral components (such as nucleic acids, proteins, and capsids), assembly of new viral particles, and ultimately lysis (rupture) of the host cell to release the newly formed viruses. Integration does not occur within the host cell and thus no prophages are formed.
The newly released viruses can then infect other host cells and continue the cycle of infection and replication.
Lytic Cycle:
Absorption: attach to cell
Entry: inject DNA, discard capsid
Replication: Cell’s nucleus takes in DNA and makes many copies of viral DNA
Assembly: viral capsids are made from instructions in viral DNA
Lysis: host cell bursts & dies, virus released
Lysogenic Cycle - Long Cycle:
In the lysogenic cycle, the virus integrates its genetic material (DNA or RNA) into the host cell’s genome, becoming a prophage (in the case of bacteriophages) or provirus (in the case of animal viruses).
Once integrated, the viral genetic material replicates along with the host cell’s DNA during normal cell division and is passed on to daughter cells. Prophages are formed.
The virus may remain dormant, not actively producing new virus particles, and coexisting with the host cell for an extended period. Lysis does not occur.
Under certain conditions or triggers (e.g., environmental stress), the virus may exit the lysogenic cycle and enter the lytic cycle, initiating active replication and the production of new viral particles.
The overall concept of evolution - what defines it?
Evolution is a big idea in biology that explains how life has changed over a really long time. It happens because species gradually change through things like natural selection, where favourable traits make animals more likely to survive and have babies. The concept of common ancestry means all living things are connected through their shared evolutionary history. The variety in traits comes from genetic changes caused by things like mutations. Eventually, these changes can lead to new species forming (speciation). Evidence from fossils, comparative anatomy, and studying molecules like DNA all support the idea of evolution. It’s an ongoing process that has made all the different types of living things we have today, showing how living things adapt and stick together over a really long time.
Fully understand Darwin’s Finches - adaptive radiation.
Adaptive Radiation
The relatively rapid evolution of a single species into many distinct but closely related species
Evolution of many diversely adapted species from a common ancestor
Often evident in anatomical homologies (homologous structures)
Occurs when new resources become available
Each new species fill a variety of formerly empty ecological niches
Ex. Hawaiian Islands
Example of Adaptive Radiation
Galapagos finches have adapted to eat very specific diets.
Daphne Major
Daphne major is a volcanic island that forms past the archipelago that is collectively referred to as the Galapagos Islands
It is the native habitat of a variety of bird species known as Darwin’s finches (subfamily: Geospiznae)
Darwin’s finches demonstrate adaptive radiation and show marked variations in beak size and shape according to diet
Finches that feed on seeds possess compact, powerful beaks – with larger beaks better equipped to crack larger seed cases
In 1977, an extended drought changed the frequency of larger beak sizes within the population by natural selection
Dry conditions result in plants producing larger seeds with tougher seed casings
Between 1976 and 1978 there was a change in average beak depth within the finch population
Finches with larger beaks were better equipped to feed on the seeds and thus produced more offspring with larger beaks
Full role of fungi from notes
The structures of fungi are adapted for two functions: nutrient absorption and reproduction.
Fungi are saprophytes, organisms that feed on dead or decaying matter. Digestion takes place externally and nutrient absorption takes place in the mycelium, a mesh of branching filaments on or below the surface.
Each of the filaments is called a hypha (ae).
Moulds reproduce mainly by asexual reproduction, using spores.
How? The spores are released from sporangium and travel through
the air. When the spore lands in a favourable environment, a new mold
grows as each spore divides by mitosis. The hyphae of the mold are haploid.
Most moulds can reproduce sexually, involving fusion of hyphae.
How? Through the fusion of two hyphae from two compatible moulds.
Once fused, a zygospore forms. If there is enough moisture and nutrients
available, a sporangium is produced from the zygospore. Cells will then
undergo meiosis and the haploid spores that develop are released.
Importance of Fungi:
Benefits of Fungi to Humans:
Yeast 🡪 bread, wine, beer
Penicillium 🡪 antibiotics
Aspergillus 🡪 flavouring
Mushrooms, morels + truffles 🡪 delicacies
Fungi are useful in decomposing pollutants 🡪 dumpsites
Symbiotic Relationships:
“A mutually beneficial relationship with another organism”
ex. Mycorrhizae Fungi
fungal hyphae help absorb nutrients (Phosphorus) for plants
fungi obtain sugars from plants
Importance of Lichens (Ex of Symbiosis)
“Lichen” is a combination of 2 organisms –green algae (cyanobacterium) and sac fungus
important for plant succession – it can grow on bare rock and create soil
Lichens absorb pollutants directly from the air (this makes them useful to researchers collecting data on air pollution)
Full role of fungi from video watched in class
Introduction:
Paul Stamets’ TED Talk is an in-depth analysis of fungi’s different and important role in tackling current environmental issues. Stamets introduces six mycological solutions, all centred on the flexible and resilient mycelium, the vegetative part of fungi. The following summary will go into the major concepts offered by Stamets, providing an in-depth understanding of fungi’s critical role in ecological sustainability.
Soil Stabilization and Mycelial Tenacity:
Stamets’ argument is based on mycelium’s unique ability to stabilize soil (Imagine mycelium as nature’s glue. It’s the part of fungi that holds soil together and stops it from washing away). Mycelium has incredible tenacity, supporting 30,000 times its mass (Stamets tells us it’s super strong, supporting weight way more than itself). This unique characteristic highlights its position as the largest molecular disassembler of nature, actively attaching landscapes and avoiding erosion.
Nutrient Transfer and Symbiotic Relationships:
The key discovery is the mycelium’s role as a channel for the transfer of nutrients between plants. Stamets uses the metaphor of mycelium as a mother, which aids in the transfer of nutrients across various plant species. (Mycelium doesn’t just glue soil; it’s like a helpful messenger between plants. It helps them share nutrients like a mom passing snacks between friends. This teamwork among plants makes the whole environment healthier.)
Overcoming Mycophobia:
Stamets addresses the common fear of fungus, known as mycophobia, by broadening the story beyond traditional meanings with Portobellos and magic mushrooms. He emphasizes the importance of recognizing the different roles of fungus, challenging preexisting assumptions that frequently impede scientific progress and public perception. (Stamets wants us to stop being scared of fungi. It’s not just about the mushrooms you eat; it’s about the whole fungal family doing incredible things. So, let’s open our minds and see the cool stuff they can do.)
Mushroom Growth and Antibiotic Properties:
Mushrooms’ quick growth and production of strong antibiotics add to their significance. Stamets clarifies the close relationship between fungi and humans, which share common diseases and have medical uses. Agarikon mushrooms were discovered as possible agents against poxviruses and influenza viruses, opening up a viable area for medicinal research.
Environmental Cleanup and Pest Control:
In tests aimed at oil spills, mycelium’s cleanup capabilities are highlighted. Stamets explains how mycelium absorbs oil and by enzymes transforms hydrocarbons into carbohydrates, which contributes to the restoration of ecosystems. Also, mycelium is effective in pest management, showing its promise as an environmentally friendly alternative to standard pesticides. Stamets expands the use of mycelium for pest management, showing its efficiency against carpenter ants and termites without the use of harmful pesticides; demonstrating its promise as an environmentally friendly alternative to standard pesticides.
Mycelium as Earth’s Natural Internet:
One of the more interesting parts of Stamets’ presentation is the idea that mycelium serves as the Earth’s natural Internet. Stamets shows how mycelium creates alternate paths for the transport of nutrients and information, demonstrating its resilience and adaptability. (Stamets thinks mycelium is like Earth’s natural internet. It connects everything underground, sharing messages and making sure nutrients reach where they’re needed. It’s like the internet, but for the Earth.)
Evolutionary Significance and Carbon Sequestration:
Stamets goes into the evolutionary history of fungi, emphasizing their origin as the earliest species on land 1.3 billion years ago. Mycelium’s production of oxalic acids (two carbon dioxide molecules joined together) emerges as a significant process, aiding in rock breakdown and carbon dioxide sequestration; making the rocks crumble, and the first step in the generation of soil.
Innovative Concepts: Life Box and Econol:
Stamets introduces new ideas, such as the Life Box, a cardboard container holding mycorrhizal and endophytic fungus for reforestation. It’s a process of growing an old-growth forest with seeds with from a cardboard box. He sees mycelium as a significant role in tackling the energy crisis, using concepts such as Econol, which involves making ethanol from cellulose with ecological intelligence. ( The “Life Box” is a box that helps grow big forests from tiny seeds. And he talks about using fungi to make fuel, which could be a game-changer for our energy needs.)
Conclusion:
Finally, Paul Stamets provides a complex mosaic of mycological solutions, showing fungi as ecological guardians capable of renewing soils, creating carbon banks, and contributing to a more sustainable and resilient ecosystem. His TED Talk is a call to action, encouraging a reevaluation of fungi’s enormous potential in the ongoing effort to protect the Earth.
Viruses - all about their unique characteristics that distinguish them from living things.
Viruses possess several unique characteristics that distinguish them from living organisms. These features highlight their acellular nature, dependence on host cells, genetic variability, and distinct modes of transmission. Here’s a comprehensive overview of the key aspects:
Acellularity and Genetic Material:
Acellularity:
Definition: Viruses lack cellular structures, such as organelles and membranes, making them non-cellular entities.
Distinctive Aspect: Unlike living cells, viruses do not exhibit the organizational complexity associated with cellular life.
Genetic Material:
DNA or RNA: Viruses contain either DNA or RNA as their genetic material, but not both.
Capsid Protection: The genetic material is protected by a protein coat called a capsid, distinguishing it from the cellular nucleus or nucleoid found in living cells.
Size, Shape, and Structural Components:
Size and Shape:
Minuscule Dimensions: Viruses are significantly smaller than living cells, often less than 0.1 µm in diameter.
Shape Diversity: Viruses exhibit diverse shapes, including helical, polyhedral/icosahedral, and complex structures. This contrasts with the uniformity of cell shapes within living organisms.
Structural Components:
Capsid: The protein coat (capsid) encapsulates the genetic material and defines the virus’s shape.
Envelope: Some viruses have an outer envelope derived from the host cell membrane during the process of budding.
Nucleocapsid: Protects the viral genetic material, contributing to its stability.
Dependency on Host Cells:
Obligate Parasites:
No Independent Metabolism: Viruses lack the machinery for metabolic processes and energy production.
Host Cell Dependency: Viruses must infect host cells to replicate and survive, distinguishing them from autonomous living cells.
Host Specificity:
Specific Host Interactions: Viruses are host-specific, often infecting a particular type of host, organ, tissue, or cell.
Lock-and-Key Mechanism: Surface proteins on viruses have shapes that match host cell membrane molecules, allowing for specific host recognition.
Transmission and Spread:
Vector-Mediated Transmission:
Vectors: Viruses may be spread by vectors—living carriers that transfer viruses without getting sick.
Hosts and Vectors: While hosts get infected and can spread viruses, vectors play a role in transmission.
Multiple Entry Mechanisms:
Cell Entry Variability: Viruses enter cells through various mechanisms, such as puncturing bacterial cell walls, entering plant cells through cell wall rips, or using endocytosis for animal cells.
Evolution and Replication:
Rapid Evolution:
Mutation Rates: Viruses exhibit rapid evolution due to high mutation rates during replication.
Adaptability: This rapid evolution contributes to the emergence of new viral strains with altered characteristics.
Lytic and Lysogenic Replication:
Lytic Cycle: Viruses can replicate through the lytic cycle, causing host cell lysis.
Lysogenic Cycle: Alternatively, viruses may integrate into the host genome without immediate replication, entering a dormant state.
In summary, viruses stand apart from living organisms due to their acellular nature, reliance on host cells, unique shapes, transmission mechanisms involving vectors, and rapid evolution. Their distinct characteristics contribute to their role as obligate intracellular parasites, impacting both cellular and molecular aspects of life.
Know the term pancreas
The pancreas is a crucial organ situated behind the stomach with both endocrine and exocrine functions. Its exocrine role involves the production of pancreatic juice, which contains enzymes like proteases, specifically trypsin and chymotrypsin that break down proteins into amino acids. Additionally, the enzyme amylase is present, facilitating the further breakdown of complex polysaccharides into maltose. Furthermore, lipase plays a pivotal role in the digestion of fats, breaking them down into glycerol and three fatty acids. The pancreas also serves as an endocrine organ, releasing insulin and glucagon to regulate blood glucose levels.
Know the term karyotype
A karyotype is a visual representation of an individual’s complete set of chromosomes, arranged in pairs by size, banding patterns, and centromere position. It provides a comprehensive view of an organism’s chromosomal composition, aiding in the identification of genetic disorders, abnormalities, or variations.
Know the term paleontology
Paleontology is the scientific study of fossils, encompassing the examination of ancient life forms, their evolutionary history, and the reconstruction of prehistoric environments. Paleontologists analyze fossilized remains to unravel the mysteries of past life on Earth, providing insights into evolutionary processes and ecological dynamics.
Know the term Protista
Protista constitutes a diverse biological kingdom comprising eukaryotic organisms that do not fit into the traditional categories of plants, animals, or fungi. It encompasses a wide range of unicellular and multicellular organisms, such as algae, protozoa, and slime molds, showcasing the kingdom’s varied and unique characteristics.
Know the term Chordata
Chordata is a phylum within the animal kingdom characterized by the presence of a notochord at some stage of development. Chordates include vertebrates like fish, amphibians, reptiles, birds, and mammals. The notochord provides structural support and is a defining feature of this diverse group.
Know the term antibiotics
Antibiotics are chemical substances that inhibit the growth of or destroy bacteria. They function by targeting specific bacterial structures or processes, such as cell wall synthesis or protein production. Antibiotics are a crucial tool in medicine for treating bacterial infections, but they do not affect viruses.
Know the term taxonomy
Taxonomy is the scientific discipline involved in the identification, naming, and classification of living organisms. It encompasses hierarchical categories, such as domain, kingdom, phylum, class, order, family, genus, and species, providing a systematic framework to understand the relationships and diversity of life.
