This is a picture of a raspberry. A raspberry is an example of an aggregate fruit. Aggregate fruits develop from a flower containing more than one separate carpel, or several ovaries. When these carpels mature, they cluster together to form a single receptacle, the aggregate fruit. In contrast, a simple fruit develops from a single carpel. Examples of aggregate fruits include raspberries, blackberries, and strawberries.
Tuesday, October 18, 2016
Saturday, October 15, 2016
Osmosis
This is a picture of water. Plants rely on the nutrients and water in soil to survive. In order for water uptake to occur, plants undergo a process called osmosis. By definition, osmosis is the diffusion of free water, which is not bound to any solutes or surfaces, across a membrane. This diffusion moves water molecules from a place of higher concentration to a place of lower concentration so that a stable state of equilibrium is made. For example, when a plant cell is set in a solution that has a higher water concentration/pressure, water will move into the cell. The growth of a plant cell is primarily dependent on water uptake. Furthermore, osmosis is a function vital to plant stability. It distributes water through selectively permeable membranes to maintain proper volume and pressure of all plant cells.
Phototropism
This is a picture of a leaning plant. This plant has been affected by phototropism. Tropism is a growth response that results in plant organs leaning towards or away from any stimuli. In phototropism, the stimuli is light. The shoots of plants usually result in positive phototropism (towards the light), while the roots generally result in negative phototropism (away from the light). The cells on the plant that are farthest from the light contain a hormone chemical, auxin, that reacts when phototropism occurs. This causes the cells on the darker side of the plant to elongate faster than the cells on the brighter side, resulting in a leaning appearance. Phototropism is most often observed in plants, but can also occur in other organisms, such as fungi.
Wednesday, October 12, 2016
Mesophyll
This is a picture of a leaf. Mesophyll is the inner tissue of a leaf. It is the middle layer between the upper and lower epidermal layers. The mesophyll layer is composed of parenchyma, or photosynthetic cells with chlorophyll, which explains why it is the site of photosynthesis in leaves. The mesophyll itself is also split into two layers, including palisade mesophyll and spongy mesophyll. The palisade mesophyll layer is the upper part of the mesophyll layer and consists of tightly packed parenchyma cells that function to trap sunlight. In the spongy mesophyll, the cells are more loosely arranged, so that air spaces allow for gas exchange. With the occurrence of photosynthesis, the mesophyll layer is usually filled with gases, including carbon dioxide and oxygen.
Friday, September 9, 2016
Bottleneck Effect
This is a picture of beads in a bottle being poured out. The beads in the bottle represent a population an its gene pool. The beads remaining in the bottle represent the population and its gene pool remaining after a sudden event in the environment, such as a flood. This drastic reduction in population size due to an environmental event can cause the bottleneck effect. By chance, some alleles may be overrepresented, underrepresented, or even completely absent in the remaining population gene pool. In other words, a bottleneck can significantly reduce a populations genetic variation. Reduced genetic variation means that the population may not be able to adapt to new selection pressures, because the genetic variation that selection would act on may be out of the population. After a bottleneck effect, genetic drift will most likely have these effects on the gene pool until the population becomes large enough so that chance events have less of an impact.
Tuesday, August 30, 2016
Artificial Selection
This is a picture of broccoli. Broccoli has been cultivated from wild mustard through artificial selection. Artificial selection is a selection process in which evolution can occur. Humans have modified species, since before Darwin and Wallace, over many generations by selecting and breeding individuals that possess desired traits. An example is with how farmers and breeders have caused evolution in farm stock by only allowing plants and animals with desirable characteristics to reproduce. This process is called artificial selection because people, instead of nature, select which organisms are "better suited" to survive and reproduce.
Sunday, August 14, 2016
Gene
This is a picture of an eye, featuring its blue coloration. Eye color is an example of a phenotype, or physical characteristic, determined by genes. A gene is a unit of heredity that is passed from parent to offspring. It is a specific locus, or location, on a strand of DNA, in which the nucleotide sequencing encodes a functional RNA or protein product. Protein synthesis is what determines physical characteristics. Most biological traits are influenced by polygenes, or many different genes.
Data
This is a picture of graph paper. Graph paper can be used to collect, organize, and/or analyze data. Data is a set of quantitative or qualitative observations. In other words, it is various pieces of information such as numbers, measurements, words, or descriptions of things. Data is analyzed through graphs or images to find a conclusion of what the data means.
Thursday, August 4, 2016
Vestigial Structure
This is a picture of a penguin. Penguin "wings" are considered a vestigial structure. A vestigial structure is a structure, or organ, that has seemed to have lost all, or most, of its functions over time through the process of evolution. They provide clues to the evolutionary history of species, because they are the remnants of structures seen in ancestral species. The wings of flightless birds, such as penguins, are vestigial structures since the evolutionary function of the wing structure was to fly. Penguins use their wings to swim; not for flight.
Asexual Reproduction
This is a picture of a star fish. Starfish have the ability to reproduce asexually. Asexual reproduction is when one individual produces, using mitosis, offspring that are genetically identical to itself. It can occur as budding, fission, or spore formation, not involving the fusion of gametes. Asexual reproduction is the primary form of reproduction for single-celled organisms such as the archaebacteria, eubacteria, and protists. There are also many invertebrates, including sea anemones and sea stars, that produce by asexual reproduction.
Hermephrodite
This is a picture of a clown fish. A clown fish is an example of a hermaphrodite, an organism that has reproductive organs associated with both male and female sexes. Many groups of organisms, mostly invertebrates, do not have separate sexes. Some hermaphrodite organisms can self-fertilize, while others require a partner. Examples of hermaphrodite organisms include snails, echinoderms such as sea stars, worms, and many species of fish such as wrasse and parrot fish. A clown fish is a protogynous hermaphrodite, meaning they first function as females and then later as males.
Bilateral Symmetry
This is a picture of a bird. It has bilateral symmetry. An organism with bilateral symmetry can be divided into mirror halves through a single plane. Organisms with bilateral symmetry do not necessarly have to have both halves as perfect mirror images – often one foot or ear can be bigger than another and internal organs are not symmetric in their shape or positioning. Most organisms have bilateral symmetry including worms, insects, fish, birds, and mammals, including humans. In evolution, bilateral symmetry was important for the development of a head and the concentration of sensory organs.
Exoskeleton
This is a picture of a hermit crab. It has an exoskeleton, an external skeleton or stiff covering. An exoskeleton protects and supports an organisms body. It often has flexible joints with underlying muscles that allow for range of motion. Exoskeletons are a key feature of arthropods, a group of organisms that includes insects such as grasshoppers and cockroaches, spiders, and crustaceans such as lobsters and crabs.
Territorial Behavior
This is a picture of a dog. Dogs, although no longer wild, still display territorial behavior. Territorial behavior is the methods by which an organism, or groups of organisms, protects and separates its territory from others of its same species. Territorial boundaries can be determined by sounds, such as a bird song, or scents, such as pheromones. A dog will mark its territory and display territorial behavior in many ways, such as barking, growling, or even urinating on things.
Wednesday, August 3, 2016
Basiodiomycete
This is a picture of a mushroom. A mushroom is a basiodiomycete, an organism belonging to the basidiomycota phylum. This is a large and diverse phylum part of the kingdom Fungi. Basiodiomycete are composed of hyphae, long branching filaments of fungus. They can reproduce sexually using basidia, which is produced by the club-shaped organ, the basidium, or asexually. Fungi known as basiodiomycete include toadstools, smuts, rusts, and mushrooms.
Endosperm
This is a picture of popcorn. Popcorn contains endosperm. Endosperm is found in angiosperms, any plant that develops flowers and fruits. Endosperm functions to provide nutritive tissue to the developing embryo, or baby plant, of a seed. Popcorn, or a corn kernel/seed, has a core of soft, wet endosperm that is surrounded by a layer of hard endosperm. When heated, the water in the soft endosperm turns into steam, which expands until the pressure gets high enough for the kernel to explode, turning itself inside out. The hard endosperm then expands in volume, turning the hard kernel into popcorn.
Flower Ovary
This is a picture of an apple. An apple is the ovary of a plant. An ovary of a plant contains ovules. Through meiosis, eggs develop in the ovules. When a flower is pollinated, two sperm cells travel into these ovules. One sperm cell fertilizes the egg, while the other becomes a food source. As the ovary matures, it turns into a fruit, such as this apple, and the ovules turn into seeds. So, when you eat an apple, you are eating the mature ovary of an apple flower.
Hydrophobic
This is a picture of vegetable oil and water. The oil is hydrophobic, which means it is water-repelling. Water is a polar molecule, with its oxygen atom with a slightly negative charge and its hydrogen with a slightly positive charge. Hydrophobic molecules, such as the oil above, tend to be nonpolar molecules and therefore, prefer other neutral molecules and nonpolar solvents. So when the oil and water meet, the oil "repels" the water, and they separate.
Lipid Used for Energy Storage
This is a picture of butter. Butter is an example of a lipid used for energy storage. Lipids are mainly considered fatty acids and their derivatives, but also include carotenoids, steroids, terpenes, and bile acids. Lipids function for energy storage, hormones and vitamins, and forming cell membranes. Even though there are many types of lipids, triglycerides are used for energy storage. Triglycerides have a structure of three fatty acids bonded to glycerol. This combination packs a lot of energy and is stored as fats in animals, including humans. Butter contains triglycerides and therefore is a lipid used for energy storage.
Monday, August 1, 2016
Cambium
This is a picture of a tree. Cambium can be found in woody plants, such as the tree above. Cambium is a group of meristem cells. Meristem cells are like the equivalent to human stem cells, which are undifferentiated cells. There are two types of cambium: vascular cambium and cork cambium. The main job of vascular cambium is to give rise to xylem and phloem cells. Xylem forms the interior wood of woody plants and carries water and some nutrients from the soil to other parts of the plant. Phloem develops exterior to the cambium, forming bark, and carries nutrients, like sugar, through the plant for producing energy. Cork cambium produces cork, a part of the bark, and protects the tissue underneath.
Sunday, July 31, 2016
Animal with a Segmented Body
This is a photo of an ant. An ant has a segmented body. Segmentation is a division into separate parts or sections. In biology, this refers to the subdivision of the body of an organism into recurring segments. A segmented body is hypothesized to be an adaptation producing mobility and flexibility for an organism, increasing movement and range of motion. An ant, as seen above, is segmented into three parts: a head, thorax, and abdomen.
Mutualism
This is a picture of turtles with algae on their shells. They share mutualism. Mutualism is the relationship between two organisms of different species of which each individual benefits from the activity of the other. In the relationship between the turtles and the algae, the algae gets to grow on the shell and the turtle gets camouflage in return. Bees pollinating plants is another example of mutualism.
Radial Symmetry
This is a picture of a jellyfish. A jelly fish has radial symmetry. This is symmetry around a central axis. In other words, an organism with radial symmetry could be divided into symmetrical portions from the center, the same way a pie could be cut into slices. Some organisms with radial symmetry are aquatic cnidarians, which include corals, jellyfish, and sea anemones, and ctenophora, which are comb jellies. Dchinoderms have a unique five-point radial symmetry, which consist of starfish, sand dollars, and sea urchins.
Thursday, July 28, 2016
Autotroph
This is a picture of a flower. A flower is a typical example of an autotroph, an organism that is able to produce nutritional, organic compounds from inorganic ones using light or chemical energy. Plants, such as flowers, are prime examples of autotrophs, because they utilize photosynthesis. Photosynthesis requires sunlight and carbon dioxide to produce glucose and other similar forms of chemical energy.
Detritivore
This is a picture of a snail. A snail is an example of a detritivore. Detritivores are heterotrophs that get their nutrients by consuming detritus. Detritus is decomposing plant and animal parts as well as feces. They are important in decomposition and recycling in the nutrient cycles. Detritivores are different from decomposers, because they are unable to consume lumps of matter. Instead, they absorb and metabolize matter on a molecular scale.
Seed Dispersal
This is a picture of a seed found on the grassy ground away from the tree it came from. This shows seed dispersal. Seed dispersal is the transport of seeds away from the parent plant by wind, water, or animal. This is important, because if seeds just fell underneath the parent plant, the new plant might not receive enough sunlight, water, or nutrients from the soil. This particular seed was most likely dispersed by wind, because of the feathery pappus on the seed that catch the wind.
Wednesday, July 27, 2016
Pollen
This is a close up picture on the center part of a sunflower. This part of the sunflower has pollen. Pollen is the fertilizing element of plants. It consists of a fine, powdery, and generally yellow substance, as seen above. Pollen is excreted from the male part of the flower. Each grain contains a male gamete that can fertilize the female ovule. Pollen is transferred from plant to plant by wind, insects, such as bees, and other animals.
Frond
This is a picture of the leaf-like part of a palm tree, a frond. A frond is a large, divided leaf that often has a feathery appearance. Fronds can be found on ferns, palms, and other similar plants.
Endotherm
This is a picture of an elephant. An elephant is an endotherm. An endotherm is able to generate heat to maintain its own body temperature, even in extreme environments/temperatures. Unlike ectotherms, they do not rely on the environment for heat. Endotherms include warm-blooded organisms, such as birds and mammals. An elephant is a mammal and therefore an endotherm.
Heterotrophy
This is a picture of a giraffe. A giraffe represents heterotrophy, because a giraffe is a heterotroph, which is an organism that relies on organic compounds for food/energy, because they are unable to produce organic substances from inorganic ones. They rely on an organic source of carbon originating from other living organisms. In other words, they rely directly or indirectly on autotrophs for nutrients and food energy. For example, giraffes will consume leaves and other plants for direct nutrients. On the other hand, a lion would consume the giraffe to receive nutrients that the giraffe consumed (indirect).
Tuesday, July 26, 2016
Ectotherm
This is a picture of a lizard. A lizard is an example of an ectotherm, an organism that is dependent on external sources, such as sunlight or a heated rock surface, for body heat. In other words, an ectotherm cannot internally regulate its body temperature. The body temperature varies depending on the temperature of its environment. Examples of ectotherms are cold-blooded animals, including amphibians, reptiles, invertebrates, and fishes. A lizard is a reptile and therefore, an ectotherm.
Auxin Producing Area of a Plant
This is a picture of a developing bud of a plant, an auxin producing area. Auxin is a hormone in plants that regulates the amount, type, and direction of plant growth. Auxins are mostly produced in growth areas (meristem). They can be found in the stem, root tips, and buds.
Adaptation of an Animal
This is a picture of a male (top) peacock and female (bottom) peahen. The peacock and peahen can be used as examples of adaptations of an animal. Adaptations are behavioral and physical characteristics that have developed over time to help an organism survive in its environment. The long, brightly colored tail on the peacock is an advantageous adaption in attracting a mate. The "eyes" on the feathers of the tail also serve as a defensive adaptation in confusing threats into thinking there is more than one peacock. The female peahen has a less dramatic color scheme for the purpose of camouflage while hatching and raising offspring.
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