Kids can distinguish between boys and girls by about age 2.5. Learning appropriate pronouns comes later (3.2 for girls, 4 for boys.)
Nature vs. Nurture
Genotype (DNA, what you inherit from your parents) vs. Phenotype (traits. Measurable things, expression of the DNA)
Are our traits determined by our DNA or by out environment?
Is sex just a matter of chromosomes, or is it a learned behavior?
Traits aren’t always concordant.
Ex. Bald female- not a concordant trait for her sex
Biology: Physics, Chemistry, Biology, Psychology, Sociology
The study of living things
Goals of science: Explain, Predict, Control
Biology Axioms (basics)
All biological phenomena:
Have a physical explanation (everyone is made of atoms and molecules)
Are based on chemistry and physics
Examples: cell division, love, sympathy, parenting, washing the car
Reductionism- ???
Biological phenomena are lawful, predictable, and repeatable
Laws of biology are discovered my experiments
Theories are supported or not by experimental outcomes
Results are public, replicable, falsifiable, subject to critical discussion
Laws of biology are supported or not (theories) by experiments
Hypothesis: A causes B
Test: manipulate A, measure B
Test 1: increase A
Test 2: decrease A
Types of Molecules:
Carbohydrates: C,H,O, chains of simple sugars (like glucose)
Proteins: chains of amino acids. Most amino acids are obtained from food (environment)
Connected to form chain by peptide linkage
Proteins: folded into globular structures
They catalyze reactions (make it easier for other molecules to change, break up, fuse together, etc.)
Synthesis of hormones
Breakdown of carbs for energy
Structural proteins
Signaling molecules
All cell functions
Fats: composed of triglycerides
DNA and RNA are made from nucleic acids
DNA is made up of 4 different types of nucleotides (G-C, A-T)
23rd pair of chromosomes are sex chromosomes
In our bodies, the DNA usually aren’t coiled up perfectly in chromosomes. But when they are ready to divide and replicate, then they do.
Transcription: makes DNA into RNA
Translation: makes RNA into proteins
DNA => RNA => PROTEINS
DNA is transcribed into RNA
RNA is translated into proteins
The Genetic Triplet Code: The Amino Acid Sequence: HEGKQKYLC
Things that can go wrong:
During cell division, DNA replicated itself
-Translocations: piece of one chromosome sticks onto another one
-Inversions: a piece of the chromosome breaks off and flips
-Deletions: chromosomes looses some chunk of DNA
-Duplications: one piece of the chromosome is duplicated
-Trisomy 21 (Down Syndrome)
-Monosomy: only 2 chromosome instead of 2
Smaller mutations:
-Deletions: frame shift, amino acid change, etc., mistakes in the genetic code. Can be caused by sun or radiation or pollution
The whole rest of the protein is shifted, doesn’t work