Buscar
Estás en modo de exploración. debe iniciar sesión para usar MEMORY

   Inicia sesión para empezar

level: 9.4 Plant Reproduction

Questions and Answers List

level questions: 9.4 Plant Reproduction

QuestionAnswer
What does flowering involve?change in gene expression in shoot apex
when does flowering begin?response to length of light and dark periods
What are 3 ways in which plants reproduce?vegetative propagation: from plant cutting spore formations: moulds and ferns pollen transfer: flowering plants
What is sexual reproduction in flowering plants?pollen transfer (M gamete) to an ova (F gamete)
What are the 3 phases of sexual reproduction in flowering plants?pollination fertilization seed dispersal
What happens during pollination? (2)pollen grains are transferred from anther = stigma most plants have both structures (monoecious) = self pollination
Why is cross pollination better than self pollination?improves genetic diversity
What happens during fertilisation? (3)M gamete nuclei and f gamete nuclei forms a zygote m gamete = pollen grain f gamete = in ovule
What happens during seed dispersal?fertilisation of gametes = forms seeds = moves away from prental plant
What is the purpose of seed dispersal?reduces comeptition bw germinating seed and parental plant
What are diff methods of seed dispersal?wind water fruits animals
What is cross pollination?transferring pollen grains from 1 plant to the ovule of a diff plant
What is a mutualistic relationship?both species benefit from the interaction
How are pollinators involved in a mutualistic relationship? (2)flowering plant = sexual reproduction w/ pollen transfer animals = nutrition source (nectar)
What are some examples of pollinators?birds bats insects (bees butterflies)
Where is the pollen located?pollen grain= stamen = anther
Where is the ova located?ova = ovule = stigma = pistil
How does flowering occur? (3)develop from shoot apex by changes in gene expression = enlargement of shoot apical meristem differentiates into sepals, petals, stamen and pistil
How are the genes responsible for flowering activated? (3)abiotic factors - seasons blooms when a suitable pollinator is available day/ night length (photoperiodism)
What is photoperiodism?response to lengths of light and dark in plants
What are flowers?reproductive organs of angiospermophytes that contain male and female structures
What is the male part of the flower called? and what does it consist of? (3)stamen anther - produces pollen (m gamete) filament- stalk to hold up anther for pollinators
What is the female part of the flower called? and what does it consist of? (3)pistil /carpel stigma - sticky tip to catch pollen style - tube to connect stigma and ovule ovule = contains female gametes forms seed after fertilisation
What are the support structures in the flower?petals - brightly colored to attract pollinators sepal - outer covering to protect flower when in a bud peduncle - stalk
Draw and label a flower structure (10)petal anther filament stamen sepal peduncle ovule style stigma pistil
What is the difference between long day and short day conditions?long day = blooms in summer short day = blooms in winter/ autumn
What detects the lengths of light and dark periods?phytochromes
What are phytochromes?leaf pigments to detect light and dark
What are the 2 forms of phytochromes?inactive form (Pr) = converted into active form when it absorbs red light (660 nm) active form (Pfr) = broken down into inactive form when it absorbs far red light (725nm) = gradually goes into inactive form without light
When is the active form of phytochromes predominant?during the day
When is the inactive form of phytochromes predominant?during the night
Which type of phytochrome causes flowering?active form (Pfr)
How does Pfr differ for short day plants? (4) SID the LADflower when days are short night period = exceeds a critical length Pfr inhibits flowering = needs low levels of Pfr = long nights SID = short day inhibit flowering
How does Pfr differ for long day plants? (4) SID the LADnight period less than critical length PFR activates flowering high levels of Pfr needed short nights long day activate flowering
How can long day plants be induced to flower out of season?exposing plant to light source during night eg: carnations
How can short day plants be induced to flower out of season?covering plant with an opaque black cloth for 12 hours a day eg: crysanthemums
What are the features of a seed? (5)testa - outer seed coat that protects embryonic plant micropyle - small pore in outer covering for water cotyledon - food store for seed = embryonic leaves plumule - embryonic shoot (epicotyl) radicle - embryonic root
draw and label a seed (5)cotyledon testa micropyle radicle epicotyl / plumule
What is germination?seed emerges from a period of dormancy and sprouts
What is needed for germination? (4)oxygen - aerobic respiration (needs lot of ATP to develop) water - metabolically activates seed (triggers gibberellin production) temp - optimal temp for enzyme function pH - optimal pH for enzyme function
How can germination be measured?by the rate of seed growth over a set period of time