Food and Fibers science 7

seed plant

any plant that makes seeds

roots

• absorb water and minerals from the soil

• support/anchor the plant

• store food

leaves

• make food for the plant (photosynthesis)

• take in and release 02 and c02

• water loss (transpiration)

stem

• transport water and nutrients between roots and leaves

• xylem move water upward

• phloem move food downward

• support leaves and reproductive structures

flower

• reproduction

• has both male and female parts

• attracts pollinatorscone

cone

• reproduction

• conifers produce separate male and female cones

seeds

• contain an embryo (new plant)

• contain cotyledon (food for the embryo)

• seed coat surrounds the seed

transpiration

water evaporates from plant leaves, pulling water upwards

capillary action

the xylem are narrow, causing water to move up through capillary action

there is an attraction between water particles and the sides of the tube

making food

• plants make their own food (sugar) through photosynthesis

• occurs within chloroplasts (in cells)

• occurs in the light

• light energy + c02 + water = food + 02

using food

• plants get useable energy from food (sugar) through cellular respiration

• occurs within the mitochondria (in cells)

• occurs in the dark

• food + 02 = c02 + water + useable energy

gas exchange

• tiny openings on the underside of leaves called stomata allow gas exchange

• guard cells around the stomata control the size of the opening, so that 02 and c02 can diffuse in and out

cell membrane

the cell membrane surrounds the cell and is selectively permeable (some substances can pass and other cant)

substances pass through pores in the cell membrane

diffusion

particles move from an area of high concentration to an area of low concentration until the concentration is the same throughout the space

osmosis

water particles move from an area of high water concentration to an area of low water concentration across a selectively permeable membrane

active transport

the cell uses energy to move particles from an area of low concentration to an area of high concentration

seeds and germination

• some seeds are protected inside fruit

• seed dispersal can occur by wind, water or animal

• seeds stay inactive until growing conditions (moisture) allow germination (growth into a plant)

stamen

male parts that include anthers (pollen production and storage) and filaments (supports anthers)

the pistil (female parts) include:

• stigma: sticky, catches pollen grains

• style (support stigma

• ovary (contains ovules)

• ovules (sacs with reproductive cells)

pollination of a flower

1. a pollen grain lands on the stigma

2. a pollen tube grows from the stigma to the ovule

3. male cells move down the pollen tube to the ovule

4. the ovule grows into a seed and the ovary becomes a fruit

pollinators

• wind can carry pollen from one plant to another

• pollinators are organisms that carry pollen from flower to flower

conifers

(cone bearing plants) have separate male and female cones

male cones produce pollen

female cones contain ovules

when ovules are pollinated, seeds form on the female cones

vegetative reproduction

• reproduction of plants without seeds is called vegetative reproduction

• runners: stems grow along the surface of the soil to form new plant

• rhizomes: stems run underground to form new plants

• suckers: new plants grow from roots

technologies to reproduce plants

cuttings: cut pieces of plant that grow into new plants

grafting: attaching a part one plant onto another plant and allowing them to grow together

plants provide:

• 02

• make food

• provide shelter

• build the soil

• protect the soil

• connect living things

erosion

the movement of soil from one place to another

exposes the soil to sunlight, accelerating decomposition and leading to poor soil quality

living resources

living things used by humans

sustainable

using resources in a way that ensures they will be available to use in the future

pores

spaces between soil particles hold air or water

larger soil particles = larger pores

humus

partly decomposed organic matter

• dark color

• warm and moist

• holds water and nutrients for plants

fertilizer

nutrients that are added to the soil to help plants grow

organic fertilizers

made from animal and plant waste

chemical fertilizer

made from a mixture of chemicals

irrigation

adding water to crops

plowing

cutting into the soil and turning the top layer over to create more air space

clearing land

removing plant cover to harvest trees or make space for growing crops

crop rotation

rotating the type of crop in a field each year

yield

a measure of crop produced per area of land

• row covers

• mulch

• herbicides

• pesticides

• fertilizers

• irrigation

greenhouses

allow growers to control all growing conditions

hydroponics

a technology where plants are grown in a nutrient solution instead of soil

species

a group of organisms with similar traits that can reproduce with each other

variety

a subject of a species that has specific characteristics or traits

selective breeding

growers use selective breeding to develop new varieties of plants with desirable traits

genetic engineering

a gene from one living thing is inserted into the DNA of another living thing to change its traits.

used to make genetically modified foods that have desirable traits

problems with new varieties

• some require special treatment

• could cross with weeds to produce super weeds

herbicides

chemicals that kill plants

Pros:

• eliminate weeds, increase yield
  

Cons:

• disrupt the food web

• make soil less fertile

• harm water environments

• weeds can become resistant

pesticides

chemicals that kill insects

Pros:

• increase yield

Cons:

• kill helpful insects

• pollute the environment

• insects can become resistant

• they can remain on food

biological control

a natural predator that is introduced to feed on pests

unintended consequences

• environmental management involves balancing the needs of humans with the needs of the environment

• decisions can have unintended consequences

monoculture

• when only one plant is grown in a farm field year after year

• easy, saves money

• unintended consequences

• pest population explosions

• reduced biodiversity

• depleted soil nutrients

sustainable management

managing our resources in a way that ensures they are available into the future