Sara's Page (sarasars) Viruses, Bacteria, Cells, and Organelles
Viruses
Viruses are a deadly part of today's society. You cannot see them with the naked eye, but they are everywhere. One of the most common viruses is known as the rhinovirus, which attacks your nose. However, the rhinovirus is better known as the common cold. Despite popular belief, viruses are NOT alive. Although they do indeed reproduce, many other things that living beings do are lost on viruses. They attack the cell they are invading, projecting their RNA into the cell's genetic material and turning the nucleus into a virus factory.The cell dies soon afterward and the newborn viruses repeat the process. (Holt Life Science)
Bacteria
Bacteria are like viruses in the sense that they are not alive and create diseases that infect living organisms. Some diseases caused by bacteria are strep throat and e-coli. The definition of bacteria is: a small, single-celled organism that has a cell wall and does not have a well defined nucleus. (Holt Life Science, Brevoort Outline)
Archea
Archea are small, single-celled organisms that have a cell wall and (also) do not have a well defined nucleus. Archea are a lot like bacteria, except that they have a different ribosome structure and often turn out to be extremophiles, bacteria that love to be in extreme places where no living organism could withstand. Different types of archea are: heat-loving, salt-loving, and methane-making. (Holt Life Science, Brevoort Outline)
Cells
Cells are the basic building blocks of life. Contained in a cell are all the materials neccessary for an organism to survive. Cells are made of amino acids, special types of protein. Without cells, there would be no living organisms. (Holt Life Science) Organelles
An organelle is a specific part of a cell made to do a specific function. (Holt Life Science)
Animal Cells Functions of Animal Cell Organelles--Nucleus: contain the cell's DNA, the control center of the cell. Ribosomes: organelles where amino acids are linked to create proteins. Endoplasmic reticulum (smooth and rough): makes lipids and creates groups of proteins for the golgi complex, which processes and transports proteins. Mitochondrion: breaks down food particles, which eventually makes ATP. Chloroplast: which is made only in plant cells, transforms sunlight energy into food. Lysosome: digests food, wastes, cell parts, and identifies things that are not typical to the cell's health, including viruses and bacteria. Cytoskeleton: a web of proteins, is like a muscle and a skeleton to the cell.Cell membrane: acts like a barrier between the outside world and the cell. Golgi complex: the packaging department of the cell. (all from Holt Life Science)
Plant Cells Functions of Plant Cell Organelles That Are NOT In Animal Cells--Cell Wall: the outermost coat on a plant cell. It protects the cell from the outside world.Chloroplast: where photosynthesis takes place. There is chlorophyll in chloroplast, which is why it has a green tint.Large Central Vacuole: where water and other liquids essential to the cell are stored. Photosynthesis: the process of a plant absorbing sunlight, ultra-violet rays, water, and carbon-dioxide and the chloroplast turning it into sugar (energy) and waste (oxygen). (All from Holt Life Science)
Mitosis
Mitosis is, in eukaryotic cells, "a process of cell division that forms two new nuclei, each of which has the same number of chromosomes." The different phases of mitosis are as follows (in order): interphase (copying DNA), prophase, metaphase, anaphase, telophase, and then cytokenesis. (Holt Life Science)
Meiosis
"Meiosis is a process in cell division during which the number of chromosomes decreases to half the original number by two divisions of the nucleus, which results in the production of sex cells." In HUMANS, it results in cells with 23 chromosomes each, so when the cell is fertilized with another cell it results in a HUMAN BEING with a whopping total of. . . [drumroll please] 46 CHROMOSOMES! (Holt Life Science) Photosynthesis and Plants
All plants make their own food and have cuticles, cell walls, and a two-stage life cycle. Plants are first classified into two groups: nonvascular plants and vascular plants. Vascular plants are further divided into seedless plants, gymnosperms, and angiosperms. Similarities between green algae and plants suggest they may have a common ancestor. Nonvascular plants include liverworts, mosses, and hornworts. Seedless vascular plants include ferns, horsetails, and club mosses. The rhizoids and rhizomes of seedless plants prevent erosion by holding soil in place. The remains of seedless vascular plants that lived and died about 300 million years ago formed coal, which humans rely on for energy. Seeds nourish the young sporophyte of seed plants. Seed plant gametophytes rely on the sporophyte. Also, they do not need water for fertilization. Seeds nourish a young plant until it can make food by photosynthesis. Gymnosperms do not have flowers or fruit. Gymnosperm seeds are protected by cones. Gymnosperms are used for everyday materials, including construction utensils, paper, resin (which is used on the horsehair bow of a stringed instrument) and the all-important medicine. Angiosperms are the LUCKY plants, because they have flowers and fruits that are good for, um, admiring. However they are not just pretty to look at; they also serve higher purposes, including the essential food, the also-essential medicine, fibers for clothes (heh, gotta have that!), rubber, and, once again, building materials. Roots supply plants with water and dissolved minerals. Stems support the body of a plant, like bones support us. A leaf has a thin epidermis on its upper and lower surface. (Just F.Y.I for those of you who have no idea what it is, epidermis is "skin" on humans. I'm pretty sure the same concept applies for plants.) Most photosynthesis takes place in the the palisade layer of a leaf. The four main parts of a flower include the . . . [drumroll please] sepals, petals, stamens, and one or more pistils. Flowers are usually arranged around the pistil. The ovary of a pistil contains ovules. When the eggs are fertilized by pollen, ovules develop into seeds and the ovary becomes a fruit. (Yeah, this process REALLY isn't the same as it is for humans, in case you haven't figured that out.)
"Photosynthesis is the process by which plants make their own food." Yep--we people can't make our own food, we have to GET it (by force or asking nicely with a please or thank you). However, plants can actually make their own food through photosynthesis, which is just a fancy term for saying that plants, algae, and certain varieties of bacteria use sunlight, carbon dioxide (that is poison to humans), and water to get nutrition. (Holt Life Science)
My Favorite Organism
The polar bear (see picture) is one of my favorite organisms because they are cute and unique creatures. Unfortunately, many of them are dying at this very moment due to the evils of global warming.
(sarasars)
Viruses, Bacteria, Cells, and Organelles
Viruses
Viruses are a deadly part of today's society. You cannot see them with the naked eye, but they are everywhere. One of the most common viruses is known as the rhinovirus, which attacks your nose. However, the rhinovirus is better known as the common cold. Despite popular belief, viruses are NOT alive. Although they do indeed reproduce, many other things that living beings do are lost on viruses. They attack the cell they are invading, projecting their RNA into the cell's genetic material and turning the nucleus into a virus factory.The cell dies soon afterward and the newborn viruses repeat the process. (Holt Life Science)
Bacteria
Bacteria are like viruses in the sense that they are not alive and create diseases that infect living organisms. Some diseases caused by bacteria are strep throat and e-coli. The definition of bacteria is: a small, single-celled organism that has a cell wall and does not have a well defined nucleus. (Holt Life Science, Brevoort Outline)
Archea
Archea are small, single-celled organisms that have a cell wall and (also) do not have a well defined nucleus. Archea are a lot like bacteria, except that they have a different ribosome structure and often turn out to be extremophiles, bacteria that love to be in extreme places where no living organism could withstand. Different types of archea are: heat-loving, salt-loving, and methane-making. (Holt Life Science, Brevoort Outline)
Cells
Cells are the basic building blocks of life. Contained in a cell are all the materials neccessary for an organism to survive. Cells are made of amino acids, special types of protein. Without cells, there would be no living organisms. (Holt Life Science)
Organelles
An organelle is a specific part of a cell made to do a specific function. (Holt Life Science)
Animal Cells
Functions of Animal Cell Organelles--Nucleus: contain the cell's DNA, the control center of the cell. Ribosomes: organelles where amino acids are linked to create proteins. Endoplasmic reticulum (smooth and rough): makes lipids and creates groups of proteins for the golgi complex, which processes and transports proteins. Mitochondrion: breaks down food particles, which eventually makes ATP. Chloroplast: which is made only in plant cells, transforms sunlight energy into food. Lysosome: digests food, wastes, cell parts, and identifies things that are not typical to the cell's health, including viruses and bacteria. Cytoskeleton: a web of proteins, is like a muscle and a skeleton to the cell.Cell membrane: acts like a barrier between the outside world and the cell. Golgi complex: the packaging department of the cell. (all from Holt Life Science)
Plant Cells
Functions of Plant Cell Organelles That Are NOT In Animal Cells--Cell Wall: the outermost coat on a plant cell. It protects the cell from the outside world. Chloroplast: where photosynthesis takes place. There is chlorophyll in chloroplast, which is why it has a green tint. Large Central Vacuole: where water and other liquids essential to the cell are stored. Photosynthesis: the process of a plant absorbing sunlight, ultra-violet rays, water, and carbon-dioxide and the chloroplast turning it into sugar (energy) and waste (oxygen). (All from Holt Life Science)
Mitosis
Mitosis is, in eukaryotic cells, "a process of cell division that forms two new nuclei, each of which has the same number of chromosomes." The different phases of mitosis are as follows (in order): interphase (copying DNA), prophase, metaphase, anaphase, telophase, and then cytokenesis. (Holt Life Science)
Meiosis
"Meiosis is a process in cell division during which the number of chromosomes decreases to half the original number by two divisions of the nucleus, which results in the production of sex cells." In HUMANS, it results in cells with 23 chromosomes each, so when the cell is fertilized with another cell it results in a HUMAN BEING with a whopping total of. . . [drumroll please] 46 CHROMOSOMES! (Holt Life Science)
Photosynthesis and Plants
All plants make their own food and have cuticles, cell walls, and a two-stage life cycle. Plants are first classified into two groups: nonvascular plants and vascular plants. Vascular plants are further divided into seedless plants, gymnosperms, and angiosperms. Similarities between green algae and plants suggest they may have a common ancestor. Nonvascular plants include liverworts, mosses, and hornworts. Seedless vascular plants include ferns, horsetails, and club mosses. The rhizoids and rhizomes of seedless plants prevent erosion by holding soil in place. The remains of seedless vascular plants that lived and died about 300 million years ago formed coal, which humans rely on for energy. Seeds nourish the young sporophyte of seed plants. Seed plant gametophytes rely on the sporophyte. Also, they do not need water for fertilization. Seeds nourish a young plant until it can make food by photosynthesis. Gymnosperms do not have flowers or fruit. Gymnosperm seeds are protected by cones. Gymnosperms are used for everyday materials, including construction utensils, paper, resin (which is used on the horsehair bow of a stringed instrument) and the all-important medicine. Angiosperms are the LUCKY plants, because they have flowers and fruits that are good for, um, admiring. However they are not just pretty to look at; they also serve higher purposes, including the essential food, the also-essential medicine, fibers for clothes (heh, gotta have that!), rubber, and, once again, building materials. Roots supply plants with water and dissolved minerals. Stems support the body of a plant, like bones support us. A leaf has a thin epidermis on its upper and lower surface. (Just F.Y.I for those of you who have no idea what it is, epidermis is "skin" on humans. I'm pretty sure the same concept applies for plants.) Most photosynthesis takes place in the the palisade layer of a leaf. The four main parts of a flower include the . . . [drumroll please] sepals, petals, stamens, and one or more pistils. Flowers are usually arranged around the pistil. The ovary of a pistil contains ovules. When the eggs are fertilized by pollen, ovules develop into seeds and the ovary becomes a fruit. (Yeah, this process REALLY isn't the same as it is for humans, in case you haven't figured that out.)
"Photosynthesis is the process by which plants make their own food." Yep--we people can't make our own food, we have to GET it (by force or asking nicely with a please or thank you). However, plants can actually make their own food through photosynthesis, which is just a fancy term for saying that plants, algae, and certain varieties of bacteria use sunlight, carbon dioxide (that is poison to humans), and water to get nutrition. (Holt Life Science)
My Favorite Organism
The polar bear (see picture) is one of my favorite organisms because they are cute and unique creatures. Unfortunately, many of them are dying at this very moment due to the evils of global warming.