Comparison Asexual and Sexual Reproduction

Number ofParents

What do Offspring Look Like?

DNA

Asexual Sexual

Usually 2 parents or

combine 2 half cellsOne parent

Offspring is identical

to parent

Offspring is different

from parent

Same DNA as parentDNA is combination

of DNA of 2 parents

Asexual Sexual

Comparison Asexual and Sexual Reproduction

Asexual Reproduction

Binary fission - a ‘parent individual’ splits into two independent organisms

Bacteria and some Protists

Budding - a new individual grows on a ‘parent’

Asexual Reproduction

Some simpleAnimals

Hydra – a small jellyfish

Regeneration – an individual can grow a new part

Asexual Reproduction

Some simpleAnimals

Starfish

They produce a complete cell called spore.

Whereas a sperm or egg have ½ the DNA of the parent,the spore has all the DNA of the one parent.

Asexual Reproduction

FungiMost reproduce

asexually.

Vegetative reproduction - A new plant can grow often from a part of a plant.

Asexual Reproduction

Plants reproduce sexually

but

Can sometimes reproduce asexually

Asexual

Sexual +DNA DNA DNA

DNA DNA

Sperm Egg Zygote

Asexual

Sexual +DNA DNA DNA

DNA DNA

or

DNADNA

DNA

or

DNA DNA

All offspring identical – no variation

All offspring different– considerable variation

Sexual Reproduction

Is it such a good idea??

Advantages- produced unique genetic combinations in different individuals

xUnique offspring can cope with different niches and a changing environment

Sexual ReproductionIs it such a good idea??

Disadvantages - cost of meiosis - lose 50% of your genes every generation

eggs sperm

2 of each gene in next generation

Sexual

Advantage:

Offspring can look different

Compare sexual and asexual reproduction

Sexual Asexual

Good in variable environments

Easier to Adapt

Good in stable environmentsOnly need 1

Parent