REPRODUCTION IN FLOWERING PLANTS
Reproduction is the ability of organisms to produce a new generation of themselves.
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 material of
two parents
DIFFERENCES BETWEEN ASEXUAL AND SEXUAL REPRODUCTION
Characteristics Asexual reproduction Sexual reproduction
Number of parents One Two
Processes One stage Two stages
Gamete formation No gametes formed Gametes formed
End result Offspring are genetically identical Offspring are genetically
different
Value In unchanging (stable) In changing (unstable)
environment, well adapted environment individuals with
individuals are preserved variations can adapt to new
conditions
Rate of reproduction Faster Slower
Energy input More efficient, no energy input Less efficient, energy input
needed needed
Outside agents None needed Pollinators often necessary for
pollination
Ability to adapt to environment No Yes
Possibility of evolution Low Good
ADVANTAGES AND DISADVANTAGES OF ASEXUAL REPRODUCTION
Advantages:
1. All individuals can produce offspring
2. The process is simple and fast
, Summary by: Kaylin Teneal
3. Very useful in unchanging (stable) conditions
4. Favourable mutation can spread rapidly
Disadvantages:
1. No variation in the offspring
2. Overcrowding may occur
ADVANTAGES AND DISADVANTAGES OF SEXUAL REPRODUCTION
Advantages:
Results in variation, which:
1. Is the basis of evolution
2. Gives organisms better chance of survival
3. May prevent diseases
4. May reduce the chances of inheriting a disease from a parent.
Disadvantages:
1. High expenditure of energy
2. Reproduction process is slower
3. Unfavourable mutations and recessive genes might be expressed in the offspring
4. Outside agents may be needed
HOW SEXUAL REPRODUCTION TAKE PLACE
1. Diploid parent produces gametes (sex cells) in the gonads (sex organs) – gametes are haploid.
2. Male and female gametes are brought together by pollination (plants) or mating (animals).
3. Gamete nuclei fuse (through a process called fertilization).
4. New cell, zygote, is diploid.
5. Zygote grows by mitotic cell divison.
THE GAMETES
Female gamete is large, male gamete is small.
Animals = male gamete (sperm), female gamete (egg or ovum)
Plants = male gamete (nucleus in a pollen grain), female gamete (egg cell/ovum in an embryo sac)
ANGIOSPERM REPRODUCTION