Sexual Reproduction and Meiosis

What are advantages and disadvantages of external fertilization

• Adv:

• Little energy required to find a mate

• Large numbers of offspring produced at once

• Dis:

• Many gametes may not be fertilized

• Zygotes are unprotected from predators

• Parents do not care for offspring therefore few survive to adulthood

What are advantages and disadvantages of Internal Fertilization?

• Adv:

• Embryos are protected

• Offspring are cared for by the parents

• Dis:

• Requires more effort to find a mate

• Fewer zygotes produced

What is the process of pollination?

• Pollen grains carry sperm cells in a protective case to the ovules, which contain the egg cells.

• When pollen lands on the female part of the plant, a pollen tube forms and delivers the sperm cell to the egg cells (ovaries)

• The fertilized egg becomes a zygote, which undergoes mitosis and cell division into an embryo

• The embryo is protected by a seed coat

What happens in human prenatal devlopment?

• Early development of an organism before birth

• Development of the human zygote occurs in stages (embryonic stage (0-8 weeks) and fetal stage (8-38 weeks))

• Zygote undergoes mitosis and rapid cell divison

• Mass of dividing cells travels and implants to the lining of the uterus

What are advant

Mutations occur when part of a chromosome is:

• Inverted

• Duplicted

• Lost or Deleted

• Moved to a different location

When can Whole chromosome mutations occur

• In meiosis I when homologous chromosomes do not seperate

• In meiosis II when sister chromatids do not seperate