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.