Bio Exam
Prokaryotic
-A smaller, simple type of cell that does NOT have a membrane-bound nucleus
-Always unicellular
Eukaryotic
-A larger, complex type of cell that DOES have a membrane-bound nucleus
-Often multi-celled organisms
The three domains are Bacteria, Archaea, and Eukarya.
- Bacteria and Archaea are prokaryotes, while Eukarya are eukaryotes. (However Archaea are more close with Eukarya)
- Kingdoms are less inclusive than domains, and there are different ways to classify eukaryotes, such as the 5 or 6 kingdom systems. *we have 6
- Protista is a diverse kingdom that includes autotroph and heterotroph protists.
There are 6 different types of kingdoms
-KINGDOM ARCHAEA
-KINGDOM PROTISTA
-THE PLANT KINGDOM
-THE FUNGUS KINGDOM
-THE ANIMAL KINGDOM
-KINGDOM BACTERIA
Kingdom Archaea
-unicellular (one cell) organism
-Decomposers
-They recycling elements needed for plant life
-Archaea form relationships with other organisms in
soil.
-methanogenesis
-A biological (or chemical process) that produces
methane as the final product of metabolism
-An anaerobic process that occurs in environments that
lack oxygen, and it is often one of the final stages of
decomposition
-It appears to be a needed step for energy production
and growth of all methanogenic archaea
-Extremophile
-an organism that lives in habitats characterised in
extreme conditions (e.g. temperature, radiation, pH
level)
-mesophile
-an organism that lives in habitats characterised in
moderate conditions/temperature (not too hot or too
cold)
The Plant Kingdom
-Plants are all multicellular and consist of complex cells.
-The plant kingdom is the second largest kingdom.
-Plants are autotrophs, organisms that make their own food.
-Contain Eukaryotic cells
-All plants have cell walls made of cellulose (aka fibre) and store food in the form of starch
-Plant life cycles alternate between haploid and diploid phases, with sporophytes producing spores and gametophytes producing gametes
-Kingdom Plantae is divided into five phyla: bryophytes, lycopodiophyta, ferns, coniferophyta, and angiospermophyta
-Angiosperms are the dominant group of land plants, with two groups: monocots and dicots
-Monocots
have one seed leaf, parallel venation, scattered vascular bundles, and flower parts in multiples of three
-Dicots
have two seed leaves, reticulate venation, distinct vascular bundles, and flower parts in multiples of four or five
Grow tall
No roots, rhizoids
Need to be near water
THE FUNGUS KINGDOM
-Fungi can be responsible for diseases and extinctions
-They are responsible for decomposition, which is essential to the global food web.
-Fungi decompose organic matter, including dead trees, animals, and even forgotten fruits, recycling nutrients for plants and animals.
Fungi are essential to the global food web because they feast on the remains of almost all organisms on the planet.
-Without fungi, plants and animals could not exist because the elements they take from the soil would never return.
-Fungi are heterotrophs
an organism that eats other plants or animals for energy and nutrients.
-Fungi can be deadly
-Ants in tropical rainforests face a constant battle against different types of fungi that infect them.
KINGDOM PROTISTA
- Most protist species are unicellular organisms, however, there are a few multicellular protists such as kelp.
-Contains multicellular photosynthetic members
used to group most single-celled organisms, except bacteria and blue-green algae.
-Protista is a large and variable group containing both plant and animal characteristics.
-Seaweed
large algae growing in the sea or on rocks below the high-water mark.
Multicellular plant like produce
-Algae
alga (plural algae) is a unicellular or multicellular photosynthetic, aquatic protist
The Animal Kingdom Basics
-They are eukaryotic, multicellular organisms (their cells have no cell walls).
-They are heterotrophs that usually ingest (take in) and then digest their food.
-They are usually mobile, or have the ability to move, in at least one stage of their lives.
-They reproduce sexually and produce an embryo that undergoes stages of development.
-When a sperm and egg combine a zygote is made, then one cell mitosis happens then 2 and 3 and so on (blastula), then when more advanced and embryo forms
7 Characteristics used to classify animals
levels of organisation
-Cell layers, tissues,
number of body layers
symmetry and body plans
-Different symmetries,
body cavity
-body cavities, silom??
Segmentation
Movement
Reproduction
Invertebrate or vertebrate
35 phyla make up the animal kingdom
only one phylum—the phylum Chordata—contains animals that have backbones.
The remaining 34 phyla (invertebrates, no backbone), such as sponges, sea cucumbers, and the sea anemone make up 95 percent of the animal kingdom.
The largest number of animal species that have been identified are in Phylum Arthropoda (includes insects, spiders, lobsters, and crabs)
Animal Kingdom Definitions - Invertebrate, Vertebrate, Radial symmetry, Bilateral symmetry, Coelom and Segmentation
Invertebrate
-an animal that does not have a backbone
Vertebrate
-an animal with an internal skeleton and a backbone
Radial symmetry
-a body plan that can be divided along any plane, through a central axis, into roughly equal halves
Bilateral symmetry
-a body plan that can be divided along one plane, through the central axis, into equal halves
Coelom
-a fluid-filled body cavity that provides space for the development and suspension of organs and organ systems
Segmentation
-the division of multicellular bodies into a series of repetitive parts
Different Phylums Animalia
Phylum Porifera (Sponges) - Asymmetrical, no tissues/organs together, only 2 layers of cells, Filter feeders, Diffusion
Phylum Cnidaria - Most primitive sponges, variety of classes/main groups, 2 cell layers, Have some tissues, Stinging tentacles (around mouth), Gastrovascular cavity, Radial symmetry, Cnidarians - radial body symmetry and two basic body forms. (a polyp and a medusa
Phylum Echinodermata - Aquatic, Radial symmetry (Endoskeleton and Tube feet), water-vascular system, diffusion (mainly - to get nutrients)
Phylum: Arthropoda - The largest animal phylum, spiders/scorpions/crustaceans (such as lobsters)/insects, arthropod (jointed foot), body divided into segments, hard exoskeleton
4 Main Classes (Groups) Animalia
Arachnids (Chelicerates): spiders, mites, scorpions and ticks.
Myriapods: millipedes and centipedes
Crustaceans: crabs, lobsters, shrimp, and barnacles
Insects: beetles, bees, butterflies, moths, ants, and flies
Viruses Basics
Viruses are structures that contain strands of DNA or RNA surrounded by a protective protein coat and cannot live independently outside of cells.
They are not cellular, meaning they do not have cytoplasm, membrane-bound organelles, or cell membranes.
Some scientists do not consider viruses to be living organisms, but they have genetic material and reproduce, making them alive.
Viruses are classified into 21 groups based on their genomes, genes, and replication methods.
Lytic Cycle, Retroviruses
-The lytic cycle is the replication process in which the virus's genetic material uses the copying machinery of the host cell to make new viruses. The lysogenic cycle is the replication process in which the viral DNA enters the host cell's chromosome, which may remain dormant and later activate and instruct the host cell to produce more viruses.
-In the lytic cycle, newly formed viruses burst from the host cell, usually killing it. In multicellular hosts, these new viruses then infect neighboring cells, causing damage to their host. The amount of damage and its effects on the host may vary. In viruses that undergo the lysogenic cycle, effects on the host may not be immediate. For example, the human immunodeficiency virus (HIV) is an example of a type of virus called a retrovirus.
-Retroviruses contain an enzyme called reverse transcriptase, which causes the host cell to copy the viral RNA into DNA, forming a provirus. When the host cell divides by mitosis, it replicates the provirus along with its own DNA. Every descendant of the host cell carries a copy of the provirus in its chromosomes. This process can continue for years without harm to the host. Because the virus is part of the host chromosomes, it cannot be easily detected by medical tests. However, at any time, the provirus can separate from the host chromosomes and complete the more damaging lytic cycle.
Viruses - Prion, H and N Proteins
Prion - an infectious particle that causes damage to nerve cells in the brain, and that appears to consist mostly or entirely of a single protein
What are H and N proteins? What flu strain is most likely to cause a pandemic?
-H is the protein that gets the virus in the cell
-N is the protein that gets the virus out of the cell
-Those that affect humans are categorised as Types A, B or C. With Type A strains being the most capable of unleashing a pandemic. It turns up year after year with devastating consequences. The threat of another influenza pandemic remains.
-Avian flu and Swine flu, for instance, are two strains of Type A viruses that through mutations, can be transmitted from birds and pigs to humans
-The flu virus uses two proteins to attack its host, hemagglutinin and neuraminidase or the HA and NA proteins
Natural Selection (Basics)
natural selection - the process by which characteristics of a population change over many generations as organisms with heritable traits survive and reproduce, passing their traits to offspring
-This change happens because individuals with certain inherited traits survive specific local environmental conditions and, through reproduction, pass on their alleles to their offspring.
-For natural selection to occur, there must be diversity within a species. This is what allowed the changes in proportions of the peppered moths.
-This is also why some populations of Staphylococcus aureus survived the treatment of a certain antibiotic.
Selective Pressure
-Selective pressure is a process where individuals in a population are selected for by their environment, such as the application of antibiotics.
-This pressure can result from biotic factors such as predators, parasites, and competition for resources. In the case of young trees, those that survive in a dense forest with low light will reproduce and pass on the alleles to survive.
-Over time, the abundance of these alleles will increase, forming a population better adapted to their environment.
Natural selection is situational
-Natural selection is situational, with traits that help certain individuals survive and reproduce in different situations being inherited by the offspring of the survivors.
-Fitness refers to the contribution an organism makes to the gene pool of the next generation by producing offspring that survive long enough to reproduce.
-High fitness means that an organism will survive and reproduce, passing on advantageous genes to its offspring.
Artificial Selection (Basics)
-Artificial selection, on the other hand, has had a significant impact on human survival, with most of the food we eat coming from species that have been selectively bred.
-In natural selection, the environment determines which individuals in a population will survive and reproduce in the current conditions, which in turn affects the gene pools of future populations.
Artificial Selection - Food Crops
-Artificial selection has led to the development of food crops like rice, corn, wheat, and vegetables, such as broccoli, Brussels sprouts, and cauliflower.
-These crops are modified to increase their nutritional value, harvest yield, drought-resistant, or pest-resistant properties.
-However, these crops have limitations, such as the ability to tolerate poor soil conditions.
-To maintain genetic variation and adapt to environmental changes, crop breeders must balance selective breeding.
Selective Breeding Experiment - 1896 Illinois Experiment Station
-A selective breeding experiment at the Illinois Experiment Station in 1896 showed that corn oil production significantly increased over generations due to selective breeding.
-However, artificial selection can also have negative consequences, such as severe respiratory problems in English bulldogs and hip dysplasia in large dog breeds.
Consequences of Artificial Selection
-Genetic engineering techniques have been used to introduce new genetic information into domesticated organisms, but they also reduce genetic diversity.
-Monoculture, the practice of extensive plantings of the same species over large expanses of land, poses a significant risk to the crop population.
Gene Banks
Gene banks protect against disasters by preserving populations of early ancestors of modern plants, including food plants. These specimens, collected from wild and prehistoric sites, preserve genetic diversity for introduction into modern plants if needed.