Plants Flashcards
Define: Apical meristem
Meristematic tissuue at the extremeties of a plant (root tips, shoots and buds) that rapidly divide causing the plant to grow longer
Define: Anther
Tip of the stamen that produces pollen
Define: Cambium
Found inbetween the xylem and phloem in the vascular bundle, it contains later meristematic cells that during secondary growth form a ring and produce secondary tissue
Define: Asexual reproduction
A method of reproduction that involves only one parent cloning themselves
Define: Carpel
The femal reproductive organ that produces ovules that contains eggs
Define: chloroplast
Organelles that contain chlorophyll, site of photosynthesis
Define: Filament
Stalk that holds up the anther in the right position so that insects or wind have the best access to get the pollen
Define: Growth ring
shows the change in growing seasons as the visible rings show not so good growing conditions and the spaces in between show good growing conditions
Define: Geotropism
A plants ability to sense gravity
Define: Flower
The male and female sexual reproductive organ of a plant
Define: meristematic tissue
undifferientated cells that divide very quickly by mitosis to make a plant grow longer or wider
Define: Lateral meristem
Meristematic tissue that divides rapidly inside the cambium causing the plant to become wider/thicker
Define: Limiting factor
Environmental conditions that inhibit optimum rates of photosynthesis, ie CO2 concentrations, light intensity, temperature etc.
Define: phloem
cells withing the vascular bundel that conduct food around the plant
Define: photosynthesis
The process of producing glucose from CO2, H20, light ad chlorophyll
Define: phototropsim
A plants ability to sense a light source and grow towards to it
Define: Ovary
Base of the carpel, it produces ovules
Define: Plant
An organism that performs photosynthesis to produce energy (glucose)
Define: Pollen
Produced by the anther, it contains sperm cells
Define: Pollination
The process of pollen being transferred from one plants anther to another plants stigma
Define: Primary growth
The process where the apical meristematic cells at the tips of a plant (root tips, shoots and buds) rapidly divide producing undifferientated cells that cause the plant feature to become longer
Define: Secondary growth
The process where lateral meristematic cells in the cambium divide by mitosis producing undifferientated cells causing secondary xylem and phloem to be produced, the primary xylem on the inside is strong so it is no destroyed and causes the plant to become wider
Define: Sexual reproduction
A method of reproduction that involves 2 parents combining genetic material by meiosis
Define: Stamen
The male reproductive organ that produces pollen that contains sperm
Define: xylem
cells withing that vacscular bundles that conduct water to the leaves and also help support the plants structure
Define: Vegetative reporduction
The different methods of asexual reproduction where plants are formed no from seeds but from specialised structures of teh roots, stem or leaves
Describe the methods of each type of vegetative reproduction, give examples
Bulbs - swellings of leaves or stems at the base of the plant that when removed become a new plant, onions
Rhizomes - Underground stems that travel horozinatlly through the soil, new shoots emerge and can, if detached from the stem, grow into a new plant, Ginger
Stolons - Stems that grow over the ground horozinatally and when shoots growing on the stem detach, grow into a new plant, Strawberries
Tuber - Swollen roots or underground stems that grow into new plants, potatoes
How are roots adapted to absorbing water?
- Root hairs increase the surface area of the roots increasing the rate water can be absorbed into the plant
- the star shaped arrangement of the xlyem increases the surface area of the xylem exposed increasing the rate water can be absorbed into the xylem
How are the meristematic cells in the root tip protected?
- The root tip is produced by the root cap
- The root cap produces a slimey protective layer that helps push the tip through the soil
How does a plant grow towards a light source?
The hormone auxin causes the side facing away from the light elongate, this causes the plant to grow towards the light
How are roots and shoots effected by auxin?
- In the shoots auxin causes elongation of the shoot so it grows TOWARDS light
- in the roots auxin causes retardation of the root so it grows AWAY from the light
How does light intensity effect the rate of photosynthesis?
Higher light intensity provides the chlorophyll more energy, this means that more CO2 and H20 can react and more glucose can be produced, rate of photosynthesis increases up to the optimum level of photosythesis where the rate of photosynthesis then plateaus because another limiting factor such as CO2 concentration, temperature etc. inhibits the rate of photosynthesis
How does temerature effect the rate of photosynthesis?
The rate of photosynthesis increases as the temperature increases up to about 40-50 degrees celcius where the enzymes involved in photosynthesis begin to denature and the rate of photosynthesis then decreases
How does the concentration of chlorophyll effect the rate of photosynthesis?
Higher concentrations of chlorophyll mean that more light can be absorbed and therefore more CO2 and H2O can be combined to create glucose. The rate of photosynthesis increases as the concentration of chlorophyll increases until it reaches the optimum rate of photosynthesis and the rate of photosynthesis begins to plateau even as chlorophyll concentration increases due to another limiting factor inhibiting photosynthesis rate, ie CO2 concentrations, light intensity etc.
How does the concentration of CO2 effects the rate of photosynthesis?
higher concentrations of CO2 mean that there are more resources for glucose to be made from, rate of photosynthesis increases with more CO2 up to the optimum level a plant can photosynthesise where the rate of photosynthesis plateaus because another limiting factor inhibits such as light intensity, temperature etc. inhibits the rate of photosynthesis
How is water absorbed by the roots?
-by the process of OSMOSIS (water moving from a high to low concentration through a semipermeable membrane) -high concentration water in soil is absorbed by OSMOSIS into the low concentration vacoule of the root cells
If part of a plant grows away from a light source, what is this called? Where is an example of this?
Negative phototroipism, the roots shot negative phototropism as they grow into the ground away from light
If part of a plant responds to a light source (grow toward it), what is this called? Where is an example of this?
Positive phototropism, shoots show positive phototropism as long as they have their coleoptile attached as they grow towards the light
What are meristematic cells?
They are undifferentiated cells that rapidly divide by mitosis to make the plant bigger (lengthwise or widthwise)
What are the 3 stages of growth in the roots?
- Apical meristematic cells divide by mitosis producing undifferientated cells pushing the roots into the ground (Cell division)
- These undifferientated cells then fill their vacoules and grow wider (Cell enlargement)
These undifferientated cells then become specialised (Cell differientation)