Plant Transport
Phloem and Xylem exist together in what?
Why are flower petals colourful?
To attract pollinators.
What are enzymes?
Biological catalysts that speed up chemical reactions without being used up the reaction itself.
The phase where cells are not dividing and undergoing normal cell activity.
Interphase.
Rhizopus is a saprophytic organism. What does this mean?
Feeds on dead organic matter. Feeding occurs by absorbing dissolved materials.
A potometer is used to measure what in plants?
Name two differences between wind and insect pollinated plants.
Flowers: Large, colourful, scented vs small, green, unscented
Nectar: Nectar vs no nectar
Anthers: Inside flower vs outside flower
Stigma: Small, sticky and inside the flower vs large, feathery and outside the flower
Pollen: Spiky, large, heavy vs smooth, small, lightweight
Name an enzyme and it's substrate.
Example:
- Amylase acts on starch.
- Lactase acts on lactose.
The four phases of mitosis.
Prophase, metaphase, anaphase, telophase.
Exponential growth of a microorganism occurs during this phase.
Log phase.
What is transpiration?
The loss of water from the aerial parts of a planet. (usually the leaves)
What is the function of the testa?
Outer layer of the seed. It protects and the embryo.
What is enzyme denaturation?
An enzyme that has lost it's shape and can no longer function. It can be caused by exposure to high heats or wrong pH levels.
The different ways cytokinesis occurs in plant and animal cells.
Plant: Cell plate
Animal: Cleavage furrow
Structure that allows bacteria to remain dormant.
Endospores
Why are roots efficient at absorbing water and minerals from the soil?
Presence of root hairs, thin cell walls and a large surface area.
Name two growth regulators in flowering plants.
Abscisic acid: initiates dormancy.
Gibberellins: stimulates the production of enzymes to break starch to sugar to aid embryo growth.
Ethylene: Breaks dormancy cycle.
Auxins: Lengthen radicle and plumule.
Cytokinins: Move to the root and shoot tip to maintain embryo growth.
The use of enzymes is vital to industry. Name two industries (with examples) that use enzymes.
Food and beverages:
- Protease tenderises meat and enhances bread texture.
- Amylase breaks down starch in beer production to produce sugars for fermentation to occur and enhance flavour.
Biofuels:
- Cellulase breaks down cellulose in plants for bioethanol production.
- Lipase breaks down vegetable oil for biodiesel production.
Medicine and Pharma:
- Used in glucometers, pregnancy tests, enzyme replacement therapy, vaccine manufacturing, to treat antibiotic illnesses.
The name of the part of a gene that controls the rate of mitosis.
Proto-oncogene.
Two factors that affect the growth of microorganisms.
pH, temperature.
Xylem and Phloem have adaptations that make the efficient at transporting materials. Name one for each.
Xylem: 1. Dead, hollow cells. 2. Lignified walls. 3. No end walls. 4. Presence of pits.
Phloem: 1. Sieve plates. 2. Companion cells.
What is double fertilisation?
One pollen sperm will fertilise the egg to form a (2n) zygote.
One pollen sperm will fertilise the two polar nuclei to form (3n) endosperm.
The active site of an enzyme and the substrate are not an exact match. The substrate can alter the the shape of the active site slightly so that it can bind and the reaction can take place. The product is made and released from the active site. The active site will then return to its original shape. What is this known as?
Induced fit model.
DNA helicase breaks down hydrogen bonds that exists between nucleotides causing the strands to separate. What do we call the point of separation?
Replication fork.
Sometimes present in a prokaryotic cell.
Flagella, plasmid, capsule