REPRODUCTION IN FLOWERING
PLANTS
What to know:
Similarities and differences between asexual and sexual
- Advantages and disadvantages
The male and female of flower (diagram) and their functions
Fertilized ovules turn into seeds and the ovary into fruit
Difference between pollination and fertilization
How reproduction has historically led to improved food crops
How genetic engineering are of benefit to food production
Examples of cultivars
Sexual reproduction is in improved varieties of food crops including polyploidy
,Reproduction: the ability of organisms to produce a new generation of themselves
- It is extremely important for the survival and evolution of a species because
through reproduction, an individual passes its genes onto the next generation.
Two types of reproduction:
Asexual - production of a new generation of the same
species by one parent.
Sexual - production of a new generation of the same
species by bringing together the genetic material of two
parents
Similarities between asexual and sexual reproduction
Produce the same kind of organisms to prevent their species from becoming extinct
Result in food being produced, which is needed to feed the world’s growing population
Advantages of asexual reproduction
All individuals can produce offspring therefore there is no expenditure of energy to
produce gametes or find a mate
The process is simple and fast as it involves only mitosis
It is very useful in stable environments
A favourable mutation can spread rapidly enabling the population to adapt quickly to
New environmental conditions
Disadvantages of asexual reproduction
Unless there is a mutation, there is no variation in the offspring as there is no
recombination of the alleles
Overcrowding may occur and resources such as food might be in short supply
Disadvantages of sexual reproduction
High expenditure of energy as in plants special organs of reproduction (flowers) need to
be produced
The reproduction process is slower than asexual reproduction as it takes time for
gamete production and the meeting of gametes
Unfavourable mutations and recessive genes may be expressed in the offspring
Outside agents may be needed in plants to carry pollen or seeds
, Differences between asexual and sexual reproduction
Characteristics Asexual reproduction Sexual reproduction
Number of parents One (all individuals can produce Two, with two genders
offspring)
Processes One stage - mitosis with no fusion Two stages - meiosis and
of cells, therefore is quicker fertilisation with fusion of two cells,
therefore is slower
Gamers formation No gametes formed Gametes formed
End result Offspring is genetically identical to Offering are genetically different to
the parent - there is no variation parents, there is variation because
because alleles are not shuffled alleles are shuffled during:
Meiosis, when gametes are formed
Fertilisation, when alleles are
joined in new combinations
Value In a stable environment, well In an unstable environment,
adapted individuals are preserved individuals with variation can adapt
Reproduction is possible where to new conditions
there are few or no mates
Rate of Faster - all individuals can produce Slower process - half population at
reproduction offspring females who do not produce
offspring
Energy input More efficient, no energy input Less efficient, energy input is
needed needed to produce gametes, and
find and court a mate
Outside agents None needed Pollinators often necessary for
pollination
Ability to adapt to No Yes
environment
Possibility of Low - usually no genotype variation Good - genotype variation
evolution
How does sexual reproduction take place?
1. The diploid parent produces gametes in the gonads by
meiosis
2. The gametes are haploid as the contain one set (n) or half
the number of chromosomes
3. The male and female gametes are brought together by
pollination (plants) or mating (animals)
PLANTS
What to know:
Similarities and differences between asexual and sexual
- Advantages and disadvantages
The male and female of flower (diagram) and their functions
Fertilized ovules turn into seeds and the ovary into fruit
Difference between pollination and fertilization
How reproduction has historically led to improved food crops
How genetic engineering are of benefit to food production
Examples of cultivars
Sexual reproduction is in improved varieties of food crops including polyploidy
,Reproduction: the ability of organisms to produce a new generation of themselves
- It is extremely important for the survival and evolution of a species because
through reproduction, an individual passes its genes onto the next generation.
Two types of reproduction:
Asexual - production of a new generation of the same
species by one parent.
Sexual - production of a new generation of the same
species by bringing together the genetic material of two
parents
Similarities between asexual and sexual reproduction
Produce the same kind of organisms to prevent their species from becoming extinct
Result in food being produced, which is needed to feed the world’s growing population
Advantages of asexual reproduction
All individuals can produce offspring therefore there is no expenditure of energy to
produce gametes or find a mate
The process is simple and fast as it involves only mitosis
It is very useful in stable environments
A favourable mutation can spread rapidly enabling the population to adapt quickly to
New environmental conditions
Disadvantages of asexual reproduction
Unless there is a mutation, there is no variation in the offspring as there is no
recombination of the alleles
Overcrowding may occur and resources such as food might be in short supply
Disadvantages of sexual reproduction
High expenditure of energy as in plants special organs of reproduction (flowers) need to
be produced
The reproduction process is slower than asexual reproduction as it takes time for
gamete production and the meeting of gametes
Unfavourable mutations and recessive genes may be expressed in the offspring
Outside agents may be needed in plants to carry pollen or seeds
, Differences between asexual and sexual reproduction
Characteristics Asexual reproduction Sexual reproduction
Number of parents One (all individuals can produce Two, with two genders
offspring)
Processes One stage - mitosis with no fusion Two stages - meiosis and
of cells, therefore is quicker fertilisation with fusion of two cells,
therefore is slower
Gamers formation No gametes formed Gametes formed
End result Offspring is genetically identical to Offering are genetically different to
the parent - there is no variation parents, there is variation because
because alleles are not shuffled alleles are shuffled during:
Meiosis, when gametes are formed
Fertilisation, when alleles are
joined in new combinations
Value In a stable environment, well In an unstable environment,
adapted individuals are preserved individuals with variation can adapt
Reproduction is possible where to new conditions
there are few or no mates
Rate of Faster - all individuals can produce Slower process - half population at
reproduction offspring females who do not produce
offspring
Energy input More efficient, no energy input Less efficient, energy input is
needed needed to produce gametes, and
find and court a mate
Outside agents None needed Pollinators often necessary for
pollination
Ability to adapt to No Yes
environment
Possibility of Low - usually no genotype variation Good - genotype variation
evolution
How does sexual reproduction take place?
1. The diploid parent produces gametes in the gonads by
meiosis
2. The gametes are haploid as the contain one set (n) or half
the number of chromosomes
3. The male and female gametes are brought together by
pollination (plants) or mating (animals)
