Reproduction in flowering plants
Reproduction is the ability of an organism to provide a new generation of themselves.
Important for the survival and evolution of a species.
Two natural 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
- Sexual = material of two parents
Similarities between asexual and sexual reproduction:
1. Produce the same kind on organisms in order to prevent their species from going extinct.
2. Result in food being produced, which is vital for the world’s population.
Differences between asexual and sexual reproduction:
Characteristics Asexual reproduction Sexual reproduction
Number of parents One Two with two genders
Processes One stage - mitosis Two stages - meiosis and
fertilization
Gamete formation No gametes formed Gametes formed
End result Offspring are genetically Offspring are genetically
identical - no variation different - variation because
alleles are shuffled during
meiosis and fertilization
Value In stable and unchanging In unstable and changing
environments, well adapted environments, individuals
individuals are preserved and with variations can adapt to
reproductions possible where new conditions
there are no or few mates
Rate of reproduction Fast Slow
Energy input More efficient, no energy Less efficient, energy input
input needed needed to produce gametes
and find/court a mate
Outside agents None needed Pollinators often necessary
Able to adapt to environment No Yes
Possibly of evolution Low Good
, Advantages of asexual:
- All individuals can produce offspring
- The process is simple and fast
- Useful in stable conditions
- A favourable mutation can spread rapidly
Disadvantages of asexual:
- No variation in the offspring (unless there is a mutation)
- Overcrowding may occur
Advantages of sexual
Results in variation which:
- Is the basis of evolution
- Gives an organism a better chance of survival in an unstable environment as they are able to
adapt
- May prevent the spread of diseases
- May reduce the chance of inheriting a disease from a parent
Disadvantages of sexual:
- High energy expenditure
- Slower reproduction process
- Unfavourable mutations and recessive genes might be expressed
- Outside agents may be needed
Sexual reproduction process
More complicated than asexual.
The diploid parent produces gametes in the gonads by meiosis.
The gametes are haploid (n) as they contain one set or half the number of chromosomes.
The male and female gametes are brought together by pollination (plants) or mating (animals).
The gamete nuclei then fuse, a process known as fertilization.
The new cell, the zygote, is diploid (2n) as it has two sets of chromosomes.
The zygote grows by mitotic cell division into a new individual.
Parent organisms (2n)
Gonads
Meiosis Meiosis
Gamete (n) Gamete (n)
Fertilization
Zygote (2n)
New organism
Reproduction is the ability of an organism to provide a new generation of themselves.
Important for the survival and evolution of a species.
Two natural 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
- Sexual = material of two parents
Similarities between asexual and sexual reproduction:
1. Produce the same kind on organisms in order to prevent their species from going extinct.
2. Result in food being produced, which is vital for the world’s population.
Differences between asexual and sexual reproduction:
Characteristics Asexual reproduction Sexual reproduction
Number of parents One Two with two genders
Processes One stage - mitosis Two stages - meiosis and
fertilization
Gamete formation No gametes formed Gametes formed
End result Offspring are genetically Offspring are genetically
identical - no variation different - variation because
alleles are shuffled during
meiosis and fertilization
Value In stable and unchanging In unstable and changing
environments, well adapted environments, individuals
individuals are preserved and with variations can adapt to
reproductions possible where new conditions
there are no or few mates
Rate of reproduction Fast Slow
Energy input More efficient, no energy Less efficient, energy input
input needed needed to produce gametes
and find/court a mate
Outside agents None needed Pollinators often necessary
Able to adapt to environment No Yes
Possibly of evolution Low Good
, Advantages of asexual:
- All individuals can produce offspring
- The process is simple and fast
- Useful in stable conditions
- A favourable mutation can spread rapidly
Disadvantages of asexual:
- No variation in the offspring (unless there is a mutation)
- Overcrowding may occur
Advantages of sexual
Results in variation which:
- Is the basis of evolution
- Gives an organism a better chance of survival in an unstable environment as they are able to
adapt
- May prevent the spread of diseases
- May reduce the chance of inheriting a disease from a parent
Disadvantages of sexual:
- High energy expenditure
- Slower reproduction process
- Unfavourable mutations and recessive genes might be expressed
- Outside agents may be needed
Sexual reproduction process
More complicated than asexual.
The diploid parent produces gametes in the gonads by meiosis.
The gametes are haploid (n) as they contain one set or half the number of chromosomes.
The male and female gametes are brought together by pollination (plants) or mating (animals).
The gamete nuclei then fuse, a process known as fertilization.
The new cell, the zygote, is diploid (2n) as it has two sets of chromosomes.
The zygote grows by mitotic cell division into a new individual.
Parent organisms (2n)
Gonads
Meiosis Meiosis
Gamete (n) Gamete (n)
Fertilization
Zygote (2n)
New organism
