Reproduction Details Flashcards
Advantages of asexual reproduction
-Quick
-Only single parent required
-Good genetic characteristics are always passed on
-No dispersal so offspring will be in the same favourable environment
Disadvantages of asexual reproduction
-Little variation(hence less adaptability to changing environment)
-Unlikely to withstand disease if parent is not resistant
-Lack of dispersal leads to increased competition for nutrients
How many chromosomes does a diploid cell have?
46 chromosomes(23 pairs of chromosomes)
How many chromosomes does a haploid cell have?
23 chromosomes
Nuclei of gametes are…
haploid
Nuclei of zygotes are…
diploid
Advantages of sexual reproduction
Variation of offspring(hence more adaptable to changing environment)
-More likely to withstand disease
-(In plants) Seed dispersal reduces competition for nutrients as offspring will grow in a different environment
Disadvantages of sexual reproduction
-Requires the fusion of two gametes
-Slower process
The male part of the flower is called the….
stamen
The female part of the flower is called the…
carpel/pistil
Function of the stigma
utilizes sticky surface to catch pollen
Function of the style
links stigma to ovary
Function of the ovary
contains ovules which develop into seeds after fertilization
Function of the anther
contains pollen
Function of the filament
supports the anther
Function of the petal
attracts insects for pollination
Function of the sepal
protects the flower while it is a bud
Peduncle
supports the flower
Receptacle
-connects the peduncle to the flower
-supports the flower
Function of ovule
produces and stores egg cells
Two methods of pollination
-Insect pollination
-Wind pollination
Two types of pollination
-Cross-pollination
-Self-pollination
Advantages of self-pollination
-Only one parent required(so less reliance on pollinators)
-Pollen grains do not go to waste
Disadvantages of self-pollination
-Less variation(since genes are all from the same plant)
-Less adaptable to changing environment
-Less resistant to disease
Advantages of cross-pollination
-Increased variation
-Greater adaptability to changing environment
-More resistant to disease
Disadvantages of cross pollination
-More reliance on pollinators
Features of petals in insect-pollinated flowers
Large and brightly coloured(to attract insects)
Features of petals in wind-pollinated flowers
Small and dull in colour(no need to attract insects)
Smell of insect-pollinated flowers
Sweet smell(to attract insects)
Smell of wind-pollinated flowers
No scent(no need to attract insects)
Why do insect-pollinated flowers contain nectar?
To attract insects
Why do wind-pollinated flowers contain nectar?
THEY DON’T
Pollen quantity of insect-pollinated flowers
Not much required(less wastage than with wind pollinated)
Pollen quantity of wind-pollinated flowers
Huge quantities required(most pollen doesn’t reach another flower)