HEREDITY AND REPRODUCTION

QUESTION!! How would life be different if humans could reproduce with out a mate?

ASEXUAL OR SEXUAL?

REPRODUCTION The transfer of genetic information from one generation to the next. Every organism comes from a long line of ancestors who reproduced successfully every generation.

ASEXUAL REPRODUCTION Only 1 parent. Offspring is an exact copy of the parent. Single celled organisms and bacteria. Sometimes plants.

EXAMPLES OF ASEXUAL REPRODUCTION Binary Fission Budding Spores Vegetative Reproduction Fragmentation (starfish) Parthenogenesis (whiptail lizard)

ADVANTAGES OF ASEXUAL REPRODUCTION Much faster, fast population increase. Genetic continuity (offspring are identical to parents). Limits the spread of negative traits (only organisms with those bad traits will pass them down).

DISADVANTAGES OF ASEXUAL REPRODUCTION If the environment changes, there are no variations, so the whole population may become extinct. If a bad trait occurs, all offspring will get that trait.

SEXUAL REPRODUCTION Two parents. Half the genes come from the mother while the other half come from the father. Offspring genetically different.

Special cells called gametes join together in a process known as fertilization. The sperm and egg cells combine to form one cell. The new cell ( zygote ) is the first cell of the new organism and continues to multiply itself until the organism is fully grown.

ADVANTAGES OF SEXUAL REPRODUCTION Variations in species-new combinations of traits increase organisms chances for survival. If an environment changes, the entire population will not become extinct (those with good traits will survive) Adaptations

DISADVANTAGES OF SEXUAL REPRODUCTION Takes time. Bad traits can be easily passed along.