Plants Flashcards
Photosynthesis
Use of solar energy to produce food (carbs). Occurs in the leaf.
Epidermis
Outer layer of the leaf that has a layer of wax (cuticle). Protects the leaf from attack and prevents water from leaving.
Palisade layer
Layer of the leaf where photosynthesis takes place. Spongy cells also help, but are more important for gas exchange.
Stomates
Openings on the bottom surface of the leaf that are opened and closed by guard cells. Exchange of materials needed for photosynthesis.
Chloroplast
Where reactions for photosynthesis occur. Inner fluid is called the stroma. Inside that are membrane structures called thylakoids, which are filled with chlorophyll.
Light Dependent Reactions
- Require solar energy to convert into usable energy
- Occurs in the membranes of thylakoids, electrons gain energy through sunlight and are passed down an electron transport chain.
- When chlorophyll absorbs sunlight, a molecule of water is split into oxygen and hydrogen. Oxygen is released as waste and hydrogen is used to make ATP
- ATP synthase is located in membranes of thylakoids, so ATP is made as hydrogen ions exit.
Light independent reactions/ Calvin cycle
- Take place in stroma of chloroplast.
- Depends on input provided by ATP and NADPH
- Starts with a molecule (ribulose biphosphate) that’s regenerated each time the cycle takes a turn.
- Carbon dioxide is added to rb to make a 6 carbon molecule that is broken in half to form 2 G3P molecules. These can be converted to carbs.
How are water and nutrients transported in plants?
In veins by tissues xylem and phloem.
How are water and minerals transported?
Transported upward through xylem. Root hairs grow at the tip of roots to increase surface area for absorption.
Uses cells called tracheids and vessel elements.
How is food transported?
Transported through phloem using sieve cells, which actually carry out the transport, and companion cells, which help sieve cells carry out their metabolic function.
Angiosperms
Flowering plants
Stamen
A plant’s male component. Consists of anther, which makes pollen, and filament, which supports the anther.
Pollen
Made from cells called microspores. Pollen grains contain a cell that can divide to form 2 sperm cells.
Pistil
A plant’s female component. Consists of a stigma, style, ovule, and ovary. The ovule is inside the ovary, and forms cells called megaspores, which divide to form eggs and polar bodies.
How do flowering plants reproduce?
- Pollen grains fall onto the sticky stigma and begin to germinate.
- During germination, the pollen tube grows down through the style to connect to the ovary.
- The 2 sperm from the pollen travel down the pollen tube to enter the ovary and ovule. Double fertilzation occurs, with one sperm fertilizing an egg, and the other combines with the polar bodies.
- The fertilized egg is the plant embryo. The polar bodies become endosperm and store food for the embryo.
- The entire ovule develops into a seed. The ovary develops into a fruit to protect the seed.
- The seed is released and becomes a new plant.