Introduction to Animals

Vocabulary

1. homeostasis - The condition in which an organism's internal environment is kept stable in spite of changes in the external environment.
2. adaptation - An inherited behavior or physical characteristic that helps an organism survive and reproduce in its environment.
3. vertebrate - An animal with a backbone and a spinal cord.
4. invertebrate - An animal without a backbone.
5. tissue - A group of similar cells that perform a specific function.
6. organ - A body structure that is composed of different kinds of tissues that work together.
7. radial symmetry - A body plan in which any number of imaginary lines that all pass through a central point divide the animal into two mirror images.
8. bilateral symmetry - A body plan in which a single imaginary line divides the body into left and right sides that are mirror images of each other.
9. cnidarian - A radially symmetrical invertebrate that uses stinging cells to capture food and defend itself.
10. mollusk - An invertebrate with a soft, unsegmented body; most are protected by a hard outer shell.
11. arthropod - An invertebrate that has an external skeleton, a segmented body, and jointed appendages.
12. exoskeleton - External skeleton; a tough, waterproof outer covering that protects, supports, and helps prevent evaporation of water from the body of many invertebrates.
13. echinoderm - A radially symmetrical marine invertebrate that has an internal skeleton and a system of fluid-filled tubes.
14. endoskeleton - An internal skeleton; structural support within the body of an animal.
15. chordate - An animal that has a notochord, a nerve chord, and throat pouches at some point in its life.
16. notochord - A flexible rod that supports a chordate's back just below the nerve cord.
17. vertebrae - The bones that make up the backbone of an organism. In humans, one of the 26 bones that make up the backbone.
18. ectotherm - An animal whose body temperature is determined by the temperature of its environment.
19. endotherm - An animal whose body temperature is regulated by the internal heat the animal produces.
20. fish - A vertebrate whose body temperature is determined by the temperature of its environment (ectotherms), and that lives in the water and has fins.
21. cartilage - A connective tissue that is more flexible than bone and that protects the ends of bones and keeps them from rubbing together.
22. amphibian - A vertebrate whose body temperature is determined by the temperature of its environment (ectotherms), and that lives its early life in water and its adult life on land.
23. reptile - A vertebrate whose temperature is determined by the temperature of its environment (ectotherms), that has lungs and scaly skin, and that lays eggs on land.
24. bird - A vertebrate whose body temperature is regulated by its internal heat (endotherms), lays eggs, and has feathers and a four-chambered heart.
25. mammal - A vertebrate whose body temperature is regulated by its internal heat (endotherms), and that has skin covered with hair or fur and glands that produce milk to feed its young.
26. mammary gland - An organ in female mammals that produces milk for the mammal's young.
27. monotreme - A mammal that lays eggs.
28. marsupial - A mammal whose young are born at an early stage of development, and which usually continue to develop in a pouch on their mother's body.
29. placental mammal - A mammal that develops inside its mother's body until its body systems can function independently.
30. placenta - An organ in most pregnant mammals, including humans, that links the mother and the developing embryo and allows for the passage of materials between them.

General Knowledge

Characteristics of Animals

1. Are multicellular
2. Breathe oxygen
3. Respond to stimuli
4. Made of cells, tissues, organs and organ systems
5. Reproduce (most common way of reproduction is sexual reproduction)
6. Move (to look for food, to run from danger, to look for a new habitat)
7. Are heterotrophic/consumers (can't make their own food)
8. Some are capable of regenerating lost tissues or organs

Classification of Animals

• Invertebrates
  1. Sponges - Phylum Porifera (all sponges)
  2. Cnidarians - Phylum Coelenterata (jellyfish, sea anemones, hydra and coral)
  3. Flatworms - Phylum Platyhelminthes (planaria, tapeworm)
  4. Roundworms - Phylum Nematoda (hookworm, ascaris)
  5. Segmented Worms - Phylum Annelida (earthworms, leeches)
  6. Echinoderms - Phylum Echinodermata (starfish, sea cucumbers, sea urchins)
  7. Mollusks - Phylum Mollusca (squids, snails, clams, oysters)
     • gastropods
     • bivalves
     • cephalopod
  8. Arthropods - Phylum Arthropoda (subdivided into 3)
     • arachnids (millipedes, centipedes, spiders, scorpions)
     • insects (fly, mosquito, firefly, butterfly)
     • crustaceans (shrimp, lobsters)
• Vertebrates - Phylum Chordata
  1. Fish
  2. Amphibians
  3. Reptiles
  4. Birds
  5. Mammals

Vertebrates' Characteristics

• Its phylum is Phylum Chordata
• Have skeletons that may be make of bones, cartilage, or a combination
• Divided into fish, amphibians, reptiles, birds, and mammals
• Have a backbone to support and protect the spinal cord

Invertebrates' Characteristics

• No backbone
• No spinal cord
• No internal skeleton
• Some have an outer skeleton made of a material called chitin.
• Some have tentacles with stinging cells called nematocysts.
• Many invertebrates are marine animals.

Reproduction of Animals

• Most animals reproduce sexually
• Two cells are joined in a process known as fertilization, creating a developmental process that leads to a new life. The developmental stages are:
1. zygote
2. embryo
3. fetus
4. organism
• Some insects undergo a complete metamorphosis where all the stages are clearly identified:
1. egg
2. larva
3. pupa
4. adult
• Other insects undergo an incomplete metamorphosis where the young insect resembles an adult one and is called nymph.

Animal Behavior

• Animals exhibit two distinct behavior forms, these are:
• innate behavior - naturally occurring (nest building, spider web formation...)
• learned behavior - acquired through observation and practice (walking, speaking, writing, reading, flying...)
• Animals that live in groups display social behavior. Social behavior requires communication skills between the members of the group. Some animals that live in groups are:
• bees
• ants
• elephants
• lions
• wolves
• whales
• dolphins

Body Plans

• Symmetry deals with the organization and location of body parts
• There are several types of symmetry, they are:
  • radial - when all body parts have a common center
  • bilateral - when an imaginary line runs through the middle from north to south and identical body parts are on each side
  • assymetrical - animals with no symmetry (sponges)

Endotherms and Ectotherms

• Endotherms:
  • are warm-blooded
  • maintain a constant body temperature
  • birds and mammals are endotherms
• Ectotherms:
  • are cold-blooded
  • change their body temperature to the one in environment
  • fish, amphibians and reptiles are ectotherms

Fishes

• Fishes are divided into 3 groups, they are:
  1. jawless fish - Their "mouth" is round or circular in shape.
     • ex. remora, lampreys
  2. bony fish - skeleton made of bones
     • ex. chillo, dorado, goldfish, robalo, mero
  3. cartilage fish - skeleton made of cartilage
     • ex. sharks, stingrays, skates

Mammals

• Body covered with hair (fur)
• Feed milk to their young
• Are endotherms
• Have an internal skeleton
• Are divided into 3 groups
  1. placental - their young develop in the uterus and they have a placenta
  2. marsupials - are born very tender and finish their development in their mother's pouch
  3. monotrems - lay eggs

Adaptations

• In order to survive, some animals undergo different types of adaptations.
1. behavioral - migration, hibernation (rest in cold) and estivation (rest in heat) are three common behavioral adaptations
2. physical or structural - webbed feet, membranes that cover the eyes underwater, hollow bones in birds
• Animals respond to internal biological clocks that "remind" them of natural cycles.

REMEMBER TO READ YOUR NOTES AND STUDY FROM THE BOOK. YOU SHOULD ALSO STUDY FROM THE REVIEW GIVEN BY THE TEACHER.

Science Test Review (Chapter 2; Lessons 1, 2 & 3)

Vocabulary

1. virus - a tiny, non living particle that enters and then reproduces inside a living cell
2. host - an organism that a parasite lives with, in, or on, and provides a source of energy or a suitable environment for the parasite to live
3. parasite - an organism that benefits by living with, on, or in a host in a paratism interaction
4. vaccine - a substance used in a vaccination that consists of pathogens that have been weakened or killed but can still trigger the body to produce chemicals that destroy the pathogens
5. bacteria - single-celled organisms that lack a nucleus; prokaryotes, it has circular shaped DNA
6. cytoplasm - the thick fluid region located inside the cell membrane (in prokaryotes) or between the cell membrane and nucleus (in eukaryotes)
7. ribosome - a small grain-shaped organelle in the cytoplasm of a cell that produces proteins
8. flagellum - a long, whiplike structure that helps a cell move
9. celular respirsration - the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen (krebs cycle)
10. binary fission - a form of asexual reproduction in which one cell divides, forming two identical cells
11. conjugation - a form of sexual reproduction in which a unicellular organism transfers some of its genetic material to another unicellular organism
12. endospore - a structure produced by prokaryotes, such as bacteria, in unfavorable conditions; a thick wall encloses the DNA and some of the cytoplasm
13. pasteurization - a process of heating food to a temperature that is high enough to kill most harmful bacteria without changing the taste of the food, named after its inventor, Louis Pasteur
14. decomposer - an organism that gets energy by breaking down wastes and dead organisms, and returns raw materials to the soil and water
15. protist - a eukaryotic organism that cannot be classified as an animal, plant, or fungus
16. protozoan - a unicellular, animal-like protist
17. pseudopod - a "false foot" or temporary bulge of cytoplasm used for feeding and movement in some protozoans
18. contractile vacuole - the cell structure that collects extra water from the cytoplasm and expels it from the cell
19. cilia - tiny, hairlike projections on the outside of cells that move in a wavelike manner
20. algae - plantlike protists
21. pigment - a colored chemical compound that absorbs light
22. spore - in bacteria, protists and fungi, a thick-walled, tiny cell capable of surviving unfavorable conditions and then growing into a new organism

Viruses

• Viruses are tiny, nonliving particles that enter and reproduce inside a living cell. 
• Viruses are nonliving and have a protein coat that protects an inner core of genetic material. They're considered nonliving because they don't have cells and don't use their own energy to grow or respond.
• Viruses cannot make food, take in food, or produce wastes.
• All viruses cause disease.
• They are not classified as organisms.
• The only life activity performed by them is reproduction.
• They are made of DNA or RNA (core) and an outer coat of protection.
• Some diseases caused by viruses are:
  • common cold
  • chicken pox
  • smallpox
  • Polio
  • cervical cancer
  • viral meningitis
  • Flu
  • Dengue
• Viruses reproduce inside a host: living cell or organism. They cannot reproduce alone.
• Viral diseases are prevented by inoculating people and animals with vaccines.
• The virus takes over the cells' functions. Some instantly, while others take time.
• When viruses reproduce they inject their genetic material into a cell. The genetic material makes copies of itself, is released and invades other cells to continue this process. Most viruses destroy the cells in which they multiply.
• The human body produces a substance called interferon to combat viral infections.
• Vaccines have weakened viruses to provoke the formation of antibodies.
• Viruses vary in shape, they may be:
• round
• rod-shaped
• brick shaped
• bullet shaped
• robotlike shaped (bacteriophage)
• A bacteriophage is a virus that infects bacteria. Its name means "bacteria eater". It has a robotlike shape.
• Viruses are smaller than cells. They can't be seen under the microscopes you use in school. They're measures in nanometers (nm), which are billionths of meters. 
• The smallest viruses are about 20 nanometers in diameter, while the largest ones may be up to 200 nanometers in diameter.
• The average virus is quite small, even compared with the smallest cells (bacteria).
• Scientists don't use two-part names with viruses because they aren't organisms. They may be named in different ways, like:
• for the disease the cause (poliovirus)
• for the area where they were discovered (The West Nile Virus)
• Although all viruses have similar structures, their surface cells are different. Surface cells act as keys for the locks of the cells, which are the cell's surface proteins.
• A common cold virus may be compatible with the cells in the human nose and throat.
• Viruses may affect all living organisms, not just humans.
• An apple tree infected with the mosaic virus may produce less fruit.
• Dogs and cats get deadly viral diseases such as rabies and distemper.
• Gene therapy is when scientists take advantage of a virus' ability to enter a host cell. They use a virus as a "messenger service" to deliver genetic material to cells that need it. Gene therapy can be used to treat diseases such as:
• cystic fibrosis - people with this lack the genetic material to keep their lungs functioning properly

Bacteria

• Bacteria were first discovered in the late 1600s by a Dutch merchant named Anton von Leeuwenhoek, who made microscopes as a hobby. One day he noticed small wormlike organisms while looking at scrapings of his teeth.
• Bacteria live almost everywhere, but you cannot see them at simple sight, you must see them under a microscope.
• There are more bacteria in your mouth than there are people in the world.
• Bacteria are organisms that have:
• no nucleus (prokaryotes).
• DNA (circular in shape).
• Bacterial cells have characteristics which include the following:
• are surrounded by a rigid cell wall for protection
• have a cell membrane, which controls what goes out and comes in
• have ribosomes, which produce proteins, on the cytoplasm
• may have a flagellum (long, whiplike structure that helps a cell move)
• Not all bacteria cause disease, some are necessary for our own well-being. Bacteria are involved in oxygen and food production, in health maintenance and medicine production and in environmental cleanup or recycling. Some foods are prepared using bacteria:
  • yogurt
  • some cheeses
  • sausages
  • pickles
• Bacteria may live in many types of environments, even extreme ones.
• They are classified by their shape into categories:
  • coccus - round
  • bacilli - oval
  • spirilla - spiral
• Some examples of diseases caused by bacteria are:
  • dental cavities
  • tetanus (lockjaw)
  • botulism
  • strep throat
  • Tuberculosis
• Bacteria may reproduce every 20 minutes if they have the right conditions (temperature, moisture and food).
• Infections caused by bacteria are treated with antibiotics.
• Bacteria vary greatly in size, they're measured in micrometers (millionths of meters) and usually measure about 0.5 - 1 micrometer in diameter. Bacteria are bigger than viruses.
• Bacteria get energy by making food (some are autotrophs) or eating other organisms (heterotrophs).
• Bacteria convert food into energy via a process called cellular respiration, or the krebs cycle. Most bacteria need oxygen for this process, but not all of them since some bacterias die if oxygen is in their surroundings.
• Bacteria are also classified by the conditions or places where they may live:
  • Archaebacteria (Extreme Conditions)
  • Eubacteria
• They may reproduce sexually or asexually:
• Asexual reproduction is called binary fission, in this process one cell divides to form two identical cells. Bacteria grow up to twice its size to prepare for binary fission. The genetic material splits into two separate cells, therefore the offspring is genetically identical to the parent. Binary fission increases the number of bacteria.
• They may reproduce sexually via conjugation, which is the bacterium's transfer of genetic material through a thin, threadlike bridge. After the transfer the bacteria separate and as a result the bacteria obtain a combination of genetic materials. Conjugation does not increase the number of bacteria.
• When bacteria are in danger, they develop an outer protective covering called endospore. An endospore is a small, rounded, thick-walled resting cell that forms inside a bacteria cell. It encloses the cell's genetic material and some of its cytoplasm. Endospores survive for many years in harsh conditions. Since they're very light, they wait for the breeze to carry them to a new place where conditions are favorable and it opens up. The bacterium begins to grow and multiply.
• Some bacteria in soil are decomposers, they clean the environment. They're called "nature's recyclers".

Protists

• Organisms with characteristics of plants and animals are called protists. They're very diverse.
• All protists are eukaryotes. (have nucleus)
• Can be autotrophs or heterotrophs.
• Most are unicellular, but some are multicellular.
• Some cannot move, others can.
• Due to protists' diversity scientists divide them into three groups:
• animal-like protists (protozoans)
• are unicellular
• may have pseudopod, flagella, cilia
• may have a contractile vacuole (expels excess water) 
• protozoans with cilia have two nuclei, the small one takes care of reproductions and the larger one of everyday tasks in the cell
• protozoa may be disease causing parasites
• plant-like protists (algae)
• are autotrophs
• can be unicellular or multicellular
• use pigments to capture the sun's energy (exist in variety of colors)
• are an important food source
• fungus-like protists
• are heterotrophs
• have cell walls
• use spores to reproduce (tiny cells that are able to grow into a new organism)
• Examples of diseases caused by some Protozoa:
• Plasmodium - Malaria
• Entamoeba histolytica - Amoebic Dysentery
• Facciola Hepática - Liver conditions (Fascioliasis)
• There are many types of algae, or plant-like protists. These are:
• euglenoids
• green and unicellular
• found in freshwater
• most are autotrophs
• dinoflagellates
• unicellular in various colors
• have two flagella
• can light up when disturbed
• diatoms
• unicellular with glasslike walls
• when they die and pile up they make diatomaceous earth, which is good for household polishing
• red algae
• mostly multicellular seaweeds
• large absorb small amounts of light
• makes carrageenan, which is good for ice cream and conditioner
• is eaten by people in Asia
• brown algae
• multicellular seaweeds
• have holdfasts which anchor them to the ground
• float upright because of the gas they have in the bladder
• algins are extracted from it and used as a thickener in puddings
• There are three types of fungus-like protists, they are:
• slime molds
• brilliantly colored
• live in moist and shady places
• feed on bacteria and other microorganisms
• water molds and downy mildews
• live in water and moist places
• often grow as tiny threads that look like fuzz
• attack many food crops (potatoes, corn, grapes...)
• Plant-like protists may have chloroplasts and a cell wall.
• Some examples of protists are:
• • Amoeba
  • Paramecium
  • Euglenoids
  • Diatoms
• Amoeba surround food and enclose it in a vacuole.

NOTE: THIS REVIEW ONLY INCLUDES CHAPTERS 1 THROUGH 3, IT IS HIGHLY RECOMMENDED YOU READ CHAPTER 4 AND STUDY FROM YOUR NOTES. YOU SHOULD ALSO READ LESSONS 1-3.

Science Quiz Review (Bacteria, Viruses, Protists)

Vocabulary

1. virus - a tiny, non living particle that enters and then reproduces inside a living cell
2. host - an organism that a parasite lives with, in, or on, and provides a source of energy or a suitable environment for the parasite to live
3. parasite - an organism that benefits by living with, on, or in a host in a paratism interaction
4. vaccine - a substance used in a vaccination that consists of pathogens that have been weakened or killed but can still trigger the body to produce chemicals that destroy the pathogens
5. bacteria - single-celled organisms that lack a nucleus; prokaryotes, it has circular shaped DNA
6. cytoplasm - the thick fluid region located inside the cell membrane (in prokaryotes) or between the cell membrane and nucleus (in eukaryotes)
7. ribosome - a small grain-shaped organelle in the cytoplasm of a cell that produces proteins
8. flagellum - a long, whiplike structure that helps a cell move
9. celular respirsration - the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen (krebs cycle)
   
10. binary fission - a form of asexual reproduction in which one cell divides, forming two identical cells
11. conjugation - a form of sexual reproduction in which a unicellular organism transfers some of its genetic material to another unicellular organism
12. endospore - a structure produced by prokaryotes, such as bacteria, in unfavorable conditions; a thick wall encloses the DNA and some of the cytoplasm
13. pasteurization - a process of heating food to a temperature that is high enough to kill most harmful bacteria without changing the taste of the food
14. decomposer - an organism that gets energy by breaking down wastes and dead organisms, and returns raw materials to the soil and water
15. protist - a eukaryotic organism that cannot be classified as an animal, plant, or fungus
16. protozoan - a unicellular, animal-like protist
17. pseudopod - a "false foot" or temporary bulge of cytoplasm used for feeding and movement in some protozoans
18. contractile vacuole - the cell structure that collects extra water from the cytoplasm and expels it from the cell
19. cilia - tiny, hairlike projections on the outside of cells that move in a wavelike manner
20. algae - plantlike protists
21. pigment - a colored chemical compound that absorbs light
22. spore - in bacteria, protists and fungi, a thick-walled, tiny cell capable of surviving unfavorable conditions and then growing into a new organism
23. fungus - a eukaryotic organism that has cell walls, uses spores to reproduce, and is a heterotroph that feeds by absorbing its food
24. hyphae - the branching, threadlike tubes that make up the bodies of multicellular fungi
25. fruiting body - the reproductive structure of a fungus that contains many hyphae and produces spores
26. budding - a form of asexual reproduction in which a new organism grows out of the body of a parent
27. lichen - the combination of a fungus and either an alga or an autotrophic bacterium that live together in a relationship that benefits both organisms

Bacteria

• Bacteria are organisms that have:
  • no nucleus (prokaryotes).
  • DNA (circular in shape).
• Not all bacteria cause disease, some are necessary for our own well-being. Some foods are prepared using bacteria:
  • yogurt
  • some cheeses
  • sausages
  • pickles
• Bacteria may live in many types of environments, even extreme ones.
• They are classified by their shape into categories:
  • coccus - round
  • bacilli - oval
  • spirilla - spiral
• Some examples of diseases caused by bacteria are:
  • dental cavities
  • tetanus (lockjaw)
  • botulism
  • strep throat
  • Tuberculosis
• Bacteria may reproduce every 20 minutes if they have the right conditions (temperature, moisture and food).
• Infections caused by bacteria are treated with antibiotics.
• Bacteria are also classified by the conditions or places where they may live:
  • Archaebacteria (Extreme Conditions)
  • Eubacteria
• Binary fission is the process used by them to reproduce.
• When bacteria are in danger, they develop an outer protective covering called endospore.

Viruses

• All viruses cause disease.
• They are not classified as organisms.
• The only life activity performed by them is reproduction.
• They are made of DNA or RNA (core) and an outer coat of protection.
• Some diseases caused by viruses are:
  • common cold
  • chicken pox
  • smallpox
  • Polio
  • cervical cancer
  • viral meningitis
  • Flu
• Viruses reproduce inside a host: living cell or organism. (Acts like a parasite)
• Viral diseases are prevented by inoculating people and animals with vaccines.
• When viruses reproduce they inject their genetic material into a cell. The genetic material makes copies of itself, is released and invades other cells to continue this process. Almost all viruses destroy the cells in which they multiply.
• The human body produces a substance called interferon to combat viral infections.
• Vaccines have weakened viruses to provoke the formation of antibodies.

Protists

• Organisms with characteristics of plants and animals are called protists. Animal like protists are called Protozoa.
• Protozoa, like Amoeba, move by pseudopods (extension of the cytoplasm) whilst Paramecium with cilia
• .
• Some examples of protists are:
• • Amoeba
  • Paramecia
  • Euglenoids
  • Diatoms
• Amoeba surround food and enclose it in a vacuole.

REMEMBER THIS IS ONLY A REVIEW, YOU MUST ALSO STUDY FROM YOUR TEXTBOOK AND NOTES.

Plants Test Review

Vocabulary

1. clorophyll - A green photosynthetic pigment found in the chloroplasts of plants, algae, and some bacteria.
2. photosynthesis - The process by which plants and other autotrophs capture and use light energy to make food by carbon dioxide and water.
3. tissue - A group of similar cells that perform a specific functions.
4. chloroplast - An organelle in the cells of plants and some other organisms that captures energy from sunlight and changes it to an energy form that cells can use in making food.
5. vacuole - A sac-like organelle that stores water, food, and other materials.
6. cuticle - The waxy, waterproof layer that covers the leaves and stems of most plants.
7. vascular tissue - The internal transporting tissue in some plants that is made up of tubelike structures that carry water, food, and minerals.
8. nonvascular plant - A low-growing plant that lacks true vascular tissue for transporting materials.
9. rhizoid - A thin, rootlike structure that anchors a moss and absorbs water and nutrients for the plant.
10. vascular plant - A plant that has true vascular tissue for transporting materials.
11. phloem - The vascular tissue through which food moves in some plants.
12. xylem - The vascular tissue through which water and minerals move in some plants.
13. frond - The leaf of a fern plant.
14. pollen - Tiny structure (male gametophyte) produced by seed plants that contain the cell that later becomes a sperm cell.
15. seed - The plant structure that contains a young plant and a food supply inside a protective covering.
16. gymnosperm - A plant that produces seeds directly on the scales of cones - not enclosed by a protective fruit.
17. angiosperm - A flowering plant that produces seeds enclosed in a protective fruit.
18. cotyledon - A leaf produced by an embryo of a seed plant; sometimes stores food.
19. monocot - An angiosperm that has only one seed leaf.
20. dicot - An angiosperm that has two seed leaves.
21. root cap - A structure that covers the tip of a root, protecting the root from injury as the root grows through soil.
22. cambium - A layer of a cells in a plant that produces new pholem and xylem cells.
23. stoma - Small opening on the underside of a lead through which oxygen, water, and carbon dioxide can move. (plural: stomata)
24. transpiration - The process by which water is lost through a plant's leaves.
25. embryo - The young organism that develops from a zygote.
26. germination - The sprouting of the embryo out of a seed; occurs when the embryo resumes its growth following dormancy.
27. flower - The reproductive structure of an angiosperm.
28. pollination - The transfer of pollen from male reproductive structures to female reproductive structures in plants.
29. sepal - A leaf-like structure that encloses and protects the bud of a flower.
30. petal - A colorful, leaf-like structure of some flowers.
31. stamen - The male reproductive part of a flower.
32. pistil - The female reproductive part of a flower.
33. ovary - A flower structure that encloses and protects ovules and seeds as they develop.
34. sporophyte - The stage in the life cycle of a plant in which the plant produces spores.
35. gametophyte - The stage in the life cycle of a plant in which the plant produces gametes, or sex cells.
36. annual - A flowering plant that completes its life cycle in one growing season.
37. biennial - A flowering plant that completes its life cycle in two years.
38. perennial - A flowering plant that lives for more than two years.
39. fertilization - The process in sexual reproduction in which an egg cell and a sperm cell join to form a new cell.
40. zygote - A fertilized egg, produced by the joining of a sperm cell and an egg cell.
41. cone - The reproductive structure of a gymnosperm.
42. ovule - A plant structure in seed plants that produces the female gametophyte; contains an egg cell.
43. fruit - The ripened ovary and other structures of an angiosperm that enclose one or more seeds.

Characteristics of Plants

• Some of most plant's characteristics are:
• made of cells & tissues, they are multicellular (except some types of green algae)
• are autotrophs and producers (make their own food through photosynthesis)
• undergo photosynthesis
• live in the soil, or in the water
• "breathe" carbon dioxide
• have chlorophyll (green photosynthetic pigment) in chloroplasts
• produce oxygen
• Another thing that distinguishes plants is the differences in their cells. Unlike animal cells, plant cells are:
• enclosed by a cell wall which is made up of cellulose (material that makes the walls rigid) that surrounds the cell membrane
• have chloroplasts, in which there is chlorophyll (green photosynthetic pigment)
• have one large vacuole instead of many small ones, the vacuole stores many substances like water, wastes and food
• have many pigments, not just chlorophyll
• The first plants on Earth were green algae that lived in water environments.

Needs of Plants

• Plants need certain things to survive on land, like;
• to obtain water and nutrients from their surroundings
• plants grow their roots differently depending to the water in the soil
• to retain, or hold water
• the cuticle helps the plant reduce water loss
• to support their bodies
• to transport materials
• plants transport water, minerals and food from one part of their bodies to another

Benefits of Plants

• Plants provide us with many things, some of these things are:
• oxygen
• food (fruits and vegetables)
• wood
• shelter and habitat for many species
• flood and erosion prevention
• raw materials for things like
• perfume
• clothing
• paint
• shade
• beauty to the environment

Vascular Plants

• These have true roots, stems and leaves.
• These have vascular tissues forming systems (tubes) in their stem which lead to their leaves, like xylem (moves water and minerals), phloem (moves glucose, the plant's self produced food), and cambium (growth tissue which forms tree rings)
• These may not always reproduce by seeds, as they sometimes reproduce by spores, although seed plants outnumber seedless plants (which reproduce by spores) 10 to 1.
• A frond, the mature leaf of a fern, which is a seedless plant, may have several spore cases. Each of these spore cases have more or less 300 spores.
• Young fern leaves are called fiddleheads.
• We have many varieties of ferns in Puerto Rico, due to our warm and moist climate.
• Seed plants reproduce using pollen and seeds.
• Seed plants are subdivided into angiosperms and gymnosperms;
• Angiosperms produce seeds in of a fruit or vegetable; Angiosperms are divided into monocots (angiosperms that produce seeds with one seed leaf) and dicots (angiosperms that produce seeds with two seed leaves), "cot" is short for cotyledon which is the seed leaf that provides food for the embryo, and "mono" is one, whilst "di" is two. 
• Some examples of angiosperms are lemon trees, orange trees, mango trees, pear trees and apple trees. Some exaples of monocots are corn, wheat and rice. Some examples of dicots are oak trees and maple trees.

Image taken off Pearson's The Diversity of Life eText

• Gymnosperms produce naked seeds or seeds in cones, they are also known as conifers.
• Some examples of gymnosperms are all types of pine trees.
• Vascular plants have two stages in their reproduction:
• gametophyte - eggs or ovules and sperms are produces
• sporophyte - spores are produced

Nonvascular Plants

• These plants are very small and have thin cell walls, therefore they lack true roots, stems or leaves; they absorb water and nutrients from their surroundings via the processes of diffusion and osmosis.
• These plants are very important to preserve moisture in the soil.
• The "roots" of these plants are called rhizoids, they are very small and do not absorb water from the soil. They serve to anchor and absorb water from their surroundings (not the soil).
• Mosses, moriviví, hornworts and liverworts are examples of nonvascular plants.
• Mosses are the most diverse group of nonvascular plants by far, with more than 10,000 species.
• There is fewer than 100 species of hornworts, these are often living with grass plants.
• Liverworts are named because their shape is similar to a human's liver, there are more than 8,000 species of these.

Plant Structures

• One of plants' most essential parts are their roots.
• These are only found in vascular plants. Nonvascular plants have rootlike structures called rhizoids.
• These anchor a plant to the ground, absorb water and minerals from the soil, and sometimes they even store food. The more root area a plant has the more water and minerals it absorbs.
• There are two main types of roots; fibrous roots, which consist of many similarly sized roots that form a dense and tangles mass, and taproots, which consist of one long, thick main root and many smaller roots branching off it. Taproots are very hard to pull out the ground. Carrots, dandelions and cacti have taproots, whilst corn, lawn grass and onions have fibrous roots.

Image taken off Pearson's The Diversity of Life eText

• The root cap protects the root from injury as it grows into the soil and surround the root's tip.
• Root hairs grow out of the root's surface to enter the spaces between soil particles and absorb water and minerals. These also help anchor a plant to the ground.
• Xylem and phloem (vascular tissues) are at the center of the root. The water and nutrients that are absorbed move into the xylem to be transported to the plant's stems and leaves, whilst the phloem transports food manufactured in the leaves to the roots.
• Another very important part is the stem.
• The stem has two main functions, which are:
• carrying substances between the plant's roots and leaves
• providing support for the plant and hold up the leaves so they receive sunlight
• These can be either woody or herbaceous. Woody ones are very firm, rigid and usually made of wood, for example the ones in maple trees. Herbaceous stems are fragile, soft, and often do not contain wood, plants such as ivy, asparagus and daisies have herbaceous stems.
• All stems consist of phloem and xylem, as well as many other cells that support them.



Image taken off Pearson's The Diversity of Life eText

• Xylem is sometimes known as sapwood in trees.
• Leaves are another very important structure in plants.

• These capture the sun's energy and carry out photosynthesis.
• A leaf's structure is designed for photosynthesis; the cells that contain the most chloroplasts are located nearest to the leaf's upper surface, allowing them to obtain more light.
• Carbon dioxide enters the leaf through open stomata, and water rises from the plant's roots (through xylem). During photosynthesis sugar and oxygen are produced from the carbon dioxide and water. Oxygen exits the leaf through open stomata and sugar (glucose) enters the phloem and travels to the rest of the plant.
• Due to the leaf's exposion to the air, water can quickly evaporate. This process through which water evaporates from leaves is called transpiration. Plants have to slow down transpiration by closing their stomata, if they didn't do this they'd die.

Image taken off Pearson's The Diversity of Life eText          

• The stomata in leaves is where the exchange between oxygen and carbon dioxide takes place. These are on the leaf's underside. It opens and closes to control the gases and liquids that enter and exit the leaf. When stomata are open carbon dioxide enters, and oxygen and water vapor exit.
• The veins in leaves consist of xylem and phloem, which transport water and minerals to the leaf from the roots (xylem) and glucose from the leaf to the rest of the plants (phloem).
• Chloroplasts contain chlorophyll, which is the green photosynthetic pigment.
• The cuticle is an outer protective and glossy layer of the leaf.
• Many plants begin life as seeds, this is an important part of a plant.
• Inside a seed is a partially developed plant. If the seed is in a fertile area it will sprout and grown into a plant.
• Seeds are usually scattered after they form through a process called seed dispersal, which occurs in many different ways. For example:
• When an animal eats food, its seeds pass through its digestive system and are deposited elsewhere.
• Water can also spread seeds.
• Wind can help seeds travel as well.
• After a seed is dispersed, it may remain inactive for a while before it germinates. Germination occurs when the embryo begins to grow again and pushes out of the seed. This process begins when the seed absorbs water. The embryo will use stored food and the roots will first grow downward, then its stems and leaves grow upwards.
• A seed has three main parts, an embryo, stored food and a seed coat. 

  

  See book for better illustration.

• The embryo is the young plant that develops from the zygote (fertilized egg). It has the beginnings of roots, stems and leaves. The embryo is usually very small and stops growing when it is very small, but resumes afterwards and uses the stored food until it can make its own food via photosynthesis. The embryo has one or more cotyledons, or seed leaves. Food is sometimes stored either in the cotyledons, or outside the embryo.
• The outer coating of a seed is the seed coat, it protects the embryo and its food from drying out and allows the seed to remain inactive for a long time. In many plants seeds are also surrounded by a fruit (angiosperms).

Flower Structures

• When a plant is maturing, it is enclosed by leaflike structures called sepals which protect it while it develops. When the sepals fold back they reveal the flower's petals, which are generally the most colorful parts pf the flower.
• The stamens are the male reproductive parts which consist of an anther supported by a thin stalk called the filament. Pollen is made in the anther.
• The female reproductive part is the pistil, which is located at the center and consists of several parts. The sticky part on the top is the stigma which receives the pollen, which then travels through the style to reach the ovary and therefore the ovules. An ovary contains one or more ovules.

Plant Reproduction (Lesson 4)

• Plants have complex life cycles that include two different stages, the sporophyte stage and the gametophyte stage.
• In the sporophyte stage the plant produces spores or seeds, which are tiny cells that can grow into organisms.
• In the gametophyte the plant produces sperm and egg cells, two types of sex cells.
• Angiosperms are classified based on the length of their life cycles.
• Flowering plants that complete a life cycle within one growing season are called annuals. This group includes petunias, wheat and cucumbers.
• Flowering plants that complete their life cycle in two years are called biennials. In the first years biennials germinate and grow roots, as well as very short stems and leaves. At their second year, they strengthen their stems, grow more leaves and produce new flowers and seeds.
• Flowering plants live for more than two year are called perennials. Most perennials flower every year, therefore most are annuals.
• Plants reproduce differently, depending on their structures and the environment they live in. All plants undergo sexual reproduction that involves fertilization, which occurs when the sperm cell unites with the egg cell. This fertilized egg is called a zygote.
• For some plants, like algae, fertilization can only occur when there is water.
• Other plants reproduce asexually. Which only involves one parent and produces offspring genetically identical to that parent. Asexual reproduction does not involve flowers, pollination, nor seeds, therefore it occurs faster than sexual reproduction. A single plant can quickly spread in a good environment.
• Scientists take advantage of asexual reproduction, for example, they use genetically identical plants which were asexually produced for experiments. They also copy plants with favorable characteristics.
• Grafting is a way of copying plants by cutting part of a plant's stem and attaching it to another related plant species. When the plant matures it produces more than one kind of fruit.
• An example of grafting are lemon-orange trees.
• Nonvascular plants and seedless vascular plants need to live in moist environments, so when they release spores into their surroundings, where they grow into gametophytes, there must be enough water for the sperm to swim towards the egg.
• Gymnosperms reproduce by a series of steps:
1. Cone Production - Most gymnosperms produce male and female cones, however, some individual trees produce either male or female cones. A few gymnosperms don't produce cones.
2. Pollen Production and Ovule Development - Male cones produce pollen grains, whilst female cones produce ovules. The ovule late develops into a seed.
3. Egg Production - Two egg cells form inside each ovule.
4. Pollination -The transfer of pollen from a male reproductive structure to a female one. In gymnosperms wind often carries the pollen from the male cones towards the female ones.
5. Fertilization - The ovule seals in the pollen and the sperm cell fertilizes an egg inside each ovule. The zygote (fertilized egg) then develops into the embryo part of the seed.
6. Seed Development - Female cones usually remain in trees while the seeds mature. As the seeds develop, the cone gets larger. It can take up to two years for some gymnosperm seeds to mature. Male cones usually fall off the tree after they shed their pollen.
7. Seed Dispersal - When the seeds mature, the cone scales open and the wind shakes the seeds out of the cone and carries them away. Only a few seeds land in suitable places and grow into plants.
• Angiosperms also have a series of steps for reproduction:
1. Pollination - A flower is pollinated when a grain of pollen falls into the stigma. Some angiosperms are pollinated by the wind, but most rely on other organisms, like honeybees. When an animal goes to a flower for food it is coated with pollen, which may go to the next flower the animal visits' stigma.
2. Fertilization - A sperm cell joins with an egg cell inside an ovule within the ovary. The zygote begins to develop into the seed's embryo.
3. Fruit Development and Seed Dispersal - As the seed develops, the ovary changes into a fruit (ripened ovary) to enclose one or more seeds. Fruits are the means by which an angiosperms' seeds are dispersed. Animals that eat fruits help deposit them in different areas.

REMEMBER, IT IS VERY IMPORTANT YOU REVIEW YOUR NOTES AND READ THE TEXTBOOK MATERIAL ASSIGNED. YOU SHOULD ALSO STUDY FROM THE GENERAL REVIEW WHICH WAS MADE BY THE TEACHER.