Human developement

Question 1

Embryonic period of development

Answer 1

• first 8 weeks
• Cells divide
• Tissues and organs form
• Placenta forms

Question 2

Fetal period

Answer 2

• Ninth week to birth
• Baby grows rapidly and organs begin to function + coordinate to form organ systems

Question 3

Fertilization

Answer 3

Joining of ovum and sperm (Male + Female gametes) Each contains 23 chromosomes, become 46 when joined

Question 4

Zygote

Answer 4

Feritlized egg -> Single cell, has 23 PAIRS of chromosomes

Question 5

Cleavage

Answer 5

Process of cell division without enlargement of cells

Question 6

Morula

Answer 6

16 celled zygote, reaches uturus in 5-6 days

Question 7

What happens w fertilized egg when reaching uterus

Answer 7

Starts to fill with fluid that is diffueses by the uterus, fluid filled space develops, a group of cells form. Structure is now called a blastocyst.

Question 8

Blastocyst

Answer 8

Hollow structure from which new cellular structures can develop.

Question 9

3 parts of blastocyst

Answer 9

• Trophoblast: Forms chorion then placenta
• Blastocyst cavity: idk
• Inner cell mass (embryoblast): Forms embryo

Question 10

Gastrulation

Answer 10

Process of forming the primary germ layers: endoderm, mesoderm, and ectoderm

Question 11

Primary germ layers

Answer 11

Endoderm, mesoderm, and ectoderm

Question 12

When do organs start to form

Answer 12

Weeks 3-8

Question 13

Whendoes embryo posess ddistinct human shape?

Answer 13

Week 8

Question 14

Ectoderm

Answer 14

Outer Primary Germ Layer
- Outer skin (epidermis), hair, nails, sweat glands, mammary glands.
- Nervous tissue and sense organs.
- Pituitary gland.
- Tooth enamel.
- Adrenal MEDULLA.
- Eye lens.