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.