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.
External fertilization is common with?
Fish
Internal fertilization is common with?
Birds
First week
The mass of cell hollows out and is called blastula.
All tissues and organs will develop from these cells.
Embryonic stem cells.
Eight weeks
The embryo is called a fetus.
Ectoderm develops
Skin and nervous system.
Mesoderm develops
Kidneys, skeleton, muscles, blood vessels and reproductive organs.
Endoderm develops
Lungs, liver, and lining of digestive system.
What is happening during ectoderm? (First)
Fingers and toes have appeared, Ears and muscles are developing. Sexual differentiation almost complete.
What is happening during mesoderm? (Second)
Fetal movements are felt.
Eyelids open. Fetus can survive outside of mother.
What is happening during endoderm? (Third)
Rapid weight gain occurs due to accumulation of fat.
Artificial insemination
Involves collecting sperm from a male and injecting it into a female.
Assisted reproductive technologies
Removing cells from a woman’s body, fertilizing them, and placing one or ore embryos in the uterus.
Gamete intrafallopian transfer
Egg cell is mixed with sperm and injected into fallopian tubes.
Vitro fertilization
A woman’s egg cell is placed in a petri dish, and then sperm are injected into the dish.
Infertility
The inability of a couple to have a baby.
Intracytoplasmic sperm injection
Specialized procedure in which a single sperm is injected into an egg cell.
Surrogate mother
Becomes pregnant and gives birth to a child for someone else to raise.
Uterus
Where embryo develops.
Gamete intrafallopian transfer (GIFT) differs from intracytoplasmic sperm injection (ICSI) because in GIFT an embryo is formed____?
from a mixture of egg and sperm injected into fallopian tube.
Artificial insemination (AI) differs from invitro fertilization (IVF) because in AI____?
sperm is injected into a female.
Questions have been raised about assisted reproductive technologies? Why?
Not everyone agrees about what to do with the unused embryos.
They may increase the risk of birth defects.
200+ years ago
Techniques for collecting sperm from a male and injecting in into a female were first developed.
What characteristics are common in angiosperms?
They have sepals and petals. Their ability to flower sets them apart from non-flowering plant, also known as gymnosperms, allowing them a successful means of reproduction.
How can fruits be helpful in seed dispersal?
The fruits are eaten by animals and they poop the seeds out far away from the original plant to attract animals.
Pollination
Pollinators such as bees and butterflies take pollen from one plant and transfer to another plant.
Pollen Tube Germination
When the pollen enters the stigma, the generator cell splits into sperm cells which targets an ovule and a seed is complete.
Anther (male)
The part where pollen is produced.
Filament (male)
The stamen of the flower.
Stamen (male)
The pollen producing part of the flower.
Stigma (female)
The part of the pistil where pollen germinates.
Ovary (female)
The enlarged basal portion of the pistil where ovules are produced
Pistil (female)
The ovule producing part of the flower.
Style (female)
Supports the stigma and connects it to the ovary.
Zygote
A diploid cell resulting from the fusion of two haploid cells; a fertilized ovum.