BSC 1005 Unit 2 Study Guide Chapter 1 5 Kingdoms Bacteria Animals Protista Plants Fungi How organisms are classified by evolutionally and genetic relatedness not just physical features Evolutionally and genetic relatedness means that organisms evolve by natural selection and the organisms with genetic changes mutations are favorable Evolution is driven by the slow accumulation of tiny genetic changes Characteristics of Plants Plants are green mode of nutrition Plants don t move cellular structure Plants have flowers mode of reproduction Big events of evolution and their timing The first organism bacteria appeared about 3 5 billion years ago 3 billion years ago bacteria evolved photosynthesis which added oxygen to the atmosphere which allows for more complex plants to come along Multicellular organisms evolved from bacteria 1 5 billion years ago and around 1 billion years ago plants fungi and animals evolved The green plant kingdom was among the first organisms to colonize dry land which happened 450 million years ago Chapter 2 Plants are composed of cells and all cells come from pre existing cells Every cell is surrounded by a thin lipid membrane which controls the movement of substances in and out of the cell Inside the cell membrane is the cytoplasm and nucleus where DNA is located Plant cells contain a cell wall outside the cell membrane and also contain chloroplasts in the cytoplasm Cell wall provides structure and strength while the chloroplasts is the site of photosynthesis Chloroplasts are green because of chlorophyll Photosynthesis light energy is trapped by the chloroplasts and used to power a chemical reaction in which carbon dioxide from the atmosphere is combined with water to make sugars Oxygen is a by product of photosynthesis Plants use sugars from photosynthesis to help their growth and metabolism Carbon cycle Animals get their carbon and energy by eating plants Through respiration reverse chemical reaction of photosynthesis animal cells take sugar and combine them with oxygen to release energy The CO2 released by respiration goes back to the atmosphere and can be used again for photosynthesis In the carbon cycle and dead plant or animal is broken down to CO2 through the process of respiration by bacteria and fungi in the soil Xylem Moves water from roots to leaves located on side toward center of the stem Phloem Moves sugars from leaves to roots located on side toward the outside Transpiration during photosynthesis plants loose large amounts of water when transpiration occurs when the soil is dry it causes leaves to wilt and the plant to die Guard cells and stomates Stomates are a waxy layer on a leaf allowing CO2 uptake and water release Stomates are surrounded by guard cells When open the plant has plenty of water and allows Co2 into the lead and water to leave When closed less water is loss but photosynthesis can t occur Cellulose cell wall of plants are composed of compounds that are chains of sugars main component being cellulose Most abundant organic compound on earth Cellulose forms stiff rods that are highly resistant to being broken strength similar to steel Chapter 3 Basic parts of a plant Shoot consists of the stem branches and leaves Petiole each lead is attached to the stem by a stalk called the petiole Shoot tip where new cells form and where most of the plant growth takes place Lateral buds dormant shoot tips and when activated to grow will form a branch which is a new shoot system Basic parts of a flower Filament The filament is the stalk that holds the anther Anther The pollen grains form in the anther Pollen grains contain the male reproductive cells sperm Ovary The pollen grains then reach the ovary Ovule Pollen grains enter the ovule female reproductive cell Stigma Where pollen grains enter Style Pollen grains then travel down the tube called the style Plant reproduction has two steps pollination and fertilization Pollination transfer of pollen to the stigma Pollination is unique to plants Fertilization fusion of the sperm and egg to make the next plant generation Seeds and Fruits Ovule becomes the seed the ovary wall becomes the fruit Fruits and seeds are the source of most of our food Seeds are extremely nutritious Inside of a seed the embryo consists of a root shoot axis bearing two fleshy leaves called cotyledons Cotyledons store nutrients that are used by the embryo to fuel growth when the seed germinates Chapter 4 Flowers are an adaptation for pollination Wind Pollination Plants that are wind pollinated produce tons of pollen they don t have flowers with petals no need to attract pollination Some crops such as corn has flowers usually a male and female flower Animal Pollination Most plants are pollinated by animals particularly insects bees butterflies flies moths ext Animal pollinated flowers provide an attraction or something to help the animal find the flower Includes coloring shape or scent of a flower Rewards for finding these flowers are usually pollen or nectar Two types of animal pollinators Generalists visit many different kinds of flowers Specialists visit only one kind of flower Cross Pollination vs Self Pollination Cross Pollination Cross pollination creates genetic variability Self Pollination creates the same flower over and over with the same genetic makeup Fruit is an adaptation for seed dispersal The job of fruit is to assist in dispersing the seed to new locations Fruits may be either fleshy or dry A fleshy fruit is like an apple and the seeds of it can pass through digestion easily which will then cause germination Dry fruits get stuck on animals get caught in the wind shoot out get collected and scattered by animals or depend on the water to disperse fruits Chapter 5 Importance of Phytoplankton Phytoplankton are photosynthetic plankton and are the base of the food chain They produce 30 of the worlds oxygen Two main types of phytoplankton Diatoms and Dinoflagellates Diatoms Diatoms are made up of cells that mimic glass boxes because of their high amounts of silica in the cell walls They have pits striations and spines that help suspend them in water Dinoflagellates abundant in the ocean Sometimes go through huge population booms called red tides which produce deadly toxins that kill massive amounts of fish Multicellular Marine Algae green and red algae Green Algae are a plant and ancestor of all land plants 450 million years ago they grew on banks of lakes and streams giving rise to land plants Red and green algae
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