Chapter 6 9 Flashcards
Embryo
Develops from a zygote. Embryos are a source of stem cells that could be used to help cure diseases.
Human diploid cell
23 pairs of chromosomes.
What happens to the chromosomes in meiosis?
Each chromosome in the cell is duplicated once and then the cell divides twice.
First division of the cell?
Meiosis 1, which starts with a diploid cell and finishes with two haploid cells.
Second division of the cell?
Meiosis 2, which starts with two haploid cell and ends with four haploid cells.
Meiosis
Starts with one diploid cell and ends with 4 haploid cell.
Diploid number
Two sets of chromosomes.
Fertilization
Process in which gametes from two parents combine. The egg meets with the sperm and they merge their genetic information together. After the fertilization is complete, the fertilized egg is now called a zygote.
Gametes
Specialized cells; sperm from females and eggs from females.
Gametes are ?
Haploid
Sexual reproduction
Produces offspring that are genetically different from each other. Requires two parents and increases genetic diversity.
Human haploid cell
23 pairs of chromosomes.
Human body cells
46 chromosomes.
How much chromosomes does meiosis gametes produce?
Half the number of chromosomes.
External fertilization
Sperm cell and egg cell meet outside the bodies of the parents.
Internal fertilizaton
Sperm cell and egg cell meet within the female.
Embryonic development
Development during first eight weeks (First & Second month). The embryo develops, its cells divide constantly and tissues and organs form.
Differentiation
Development of organs and body structures from blastula.
Flowering plants
Internal fertilization, sperm and egg cell meet inside the female.
Four weeks
The brain and spinal cord starts to form.
Sixteen weeks
Fetal movements are felt.
Fetal development occurs?
The third to eighth month after fertilization.