Growth patterns and reproductive strategies in the lizard, Calotes
Reproductive Strategies
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Transcript of Reproductive Strategies
Reproductive Strategies
• Mitosis is the key mechanism for asexual reproduction
• Meiosis involves the production of gametes followed by fertilization.
Reproduction in Prokaryotes• Bacteria and other
prokaryotes have no nucleus, therefore, do not undergo mitosis.
• They reproduce by binary fission.
• The sequence of repeated doubling is called exponential growth. A bacteria can divide in as little as 20 minutes and produce two more cells 20 min. later.
Asexual Reproduction
Budding – a form in which a miniature version of the parent grows outside from the parent’s body.
Vegetative reproduction – strawberry plants have runners that creates a new plant.
Fragmentation – cultivation of potatoes
Parthogenesis – an unfertilized egg develops into an adult.
Alternation of Generations
• The life cycle of plants consists of two generations: a haploid generation and a diploid generation that alternate.
• Alternation of asexual reproduction examples…
The Life Cycle of a fern
The life cycle of moss
The life cycle of a conifer
The life cycle of a cnidarian – ALTERNATION OF SEXUAL CYCLE
Advantages and Disadvantages of Reproduction Strategies
• Sexual reproduction gives an opportunity for genetic variation.
• Three potential advantages:– Offers a population a way to adapt to a
changing environment– Competition among siblings may be reduced
if they are genetically diverse– Pairing of homologous chromosomes and
crossing over offer opportunities to replace or repair damaged chromosomes.
Asexual Reproduction
• Often proceeds more quickly than sexual reproduction
• Usually requires less energy• Helps to maximize the changes that individual
offspring will survive.• ____________________• Each of the new individuals that have been
reproduced, in either way, carries a set of genetic instructions that determines how members of the species will grow and develop.