OPT 1210 Lesson 3 Flashcards
How many Chromosomes do we have?
46 Or 23 pairs (22 autosomes, and 1 sex pair)
What is the structure of DNA?
Polymer of Nucleotides (Phosphate and sugar)
Deoxyribose (DNA) Nitrogenous base
Genes code for what?
1 Protein
What is a Genome?
All the genes of 1 person (30-35,000 genes)
What percentage of the genome is junk?
98%
Dominate (D) Alleles proteins produce what?
Phenotype (Visible Traits)
What is a recessive allele (d)?
A trait that is only expressed when both alleles are recessive
DD is?
Homozygotes Dominate
Dd is?
Heterozygotes
dd is?
Homozygotes Recessive
What is Polygenic Inheritance?
2 or more loci contribute to a single phenotypic trait
Skin, Eye color, Alcoholism, Heart Disease
What does the OCA2 Gene do?
Determines eye color
OCA2 on = Brown eyes
OCA2 off = Lighter eyes depending on the amount of pigment that has migrated
Histology is the study of what?
Tissues
What are the classes of tissue?
- Epithelial
- Connective
- Muscular
- Nervous
Define an organ?
Tissue structures that have distinct boundaries of 2 or more tissue types and perform a specific task.
Epithelial
Top Layer
What is the Fxn of the Connective tissue?
To hold everything together - Most plentiful in the body
What do muscle tissues do?
Shorten / contract
What is the most plentiful tissue in the body?
Connective tissue
Similar cells arise from the same region of the embryo. What are the 3 regions?
- Ectoderm
- Mesoderm
- Endoderm
What is the Ectoderm?
Outer layer of the embryotic disc. It grows through life. Becomes: Neural Retinal Pigment Ectoderm (RPE), Retina, Iris Muscle, Optic Nerve
Surfaces: Lens, Epithelium, Lacrimal Gland
What is the Mesoderm?
Middle layer of the embryotic disc. Becomes:
Bone, Muscle, Cartilage, Blood, Lymph tissue
What is the Endoderm?
Inner layer of the embryotic disc. Replaces Hypoblast.
Not Ocular: the Gut and respiratory epithelium glands
What makes up extracellular material?
Fibrous proteins (strings) and Ground substance (Glue)
What is the only cell you could see with the naked eye?
the Ovum (if it was sitting on the head of a pin)
What is sectioning?
Cutting into thin enough layers so light can go through it