Chapter 3 Flashcards
1
Q
Species heredity (4)
A
- everyone develops in similar ways at similar ages
- genetic endowment members of a species have in common
- a reason why certain patterns of development and aging are universal
- tied to darwin’s theory
2
Q
Darwin’s theory (3)
A
- genetic variation in species (they do not all share the same genes)
- some genes aid adaptation more than others do
- natural selection: genes that aid in adaptation to the environment passed on more than those that do not
3
Q
Kettlewell’s study of moths (5)
A
- a study of pollution and moth color
- light-colored moths survived in rural areas with light-colored trees
- worsening pollution led to darker moth color
- > evolution is not just about genes, development is an interaction of genes and the environment
- an example of cultural evolution: we inherit from previous generations the way we adapt to the environment and passing it down to the next generation
4
Q
The genetic code (5)
A
- zygote created at conception
- 46 chromosomes/23 pairs, one from father and one from mother
- meiosis: reproductive cell division that splits 46 to 23 chromosomes and produce one egg
- mitosis: cell division
- DNA: double helix comprises each chromosome (20-25k genes)
5
Q
twins
A
- identical twins (monozygotic): 1 ovum split into 2, genetically identical
- fraternal twins (dizygotic): 2 eggs released and each fertilized by different sperm
- non-identical twins share 50% genes
- child shares about 50% of genes with ea parent
- individuals share some gene with all kin members
6
Q
determination of sex (6)
A
- 22 of 23 chromosomes (autosomes) similar in males and females
- 23rd pair the sex chromosome
- male has 1 x and 1 y chromosome
- XX the typical genetic code for females
- X has 1100 genes, Y has 80 (many of which are involved in sperm production)
- father’s Y chromosome determines child’s gender
7
Q
mutation (4)
A
- change in structure or arrangement of one or more genes; produces a new phenotype
- can be inherited (ex. hemophilia - bleed to death)
- environmental hazards (ex. radiation)
- some mutations beneficial
8
Q
chromosome abnormality - down syndrome (3)
A
- more than 46 chromosomes
- physical: eye folds, short/stubby limbs
- mental: intellectual impact
9
Q
other sex chromosome abnormalities (3)
A
Turner syndrome: single X chromosome
-physically small, can’t reproduce, spatial/math challenges, stubby fingers
Klinefelter’s syndrome: extra X chromosome
-long limbs, feminine characteristics
Fragile X syndrome: repeated gene sequences
- problem with neuron connections
- intellectual disability, cognitive impairment
- more common in males
10
Q
genetic disease (2, 5)
A
- 97% of babies born without disease/disorders
- genetic counseling assess potential problems (Cystic fibrosis, hemophilia, PKU, stay sachs)
Sickle cell disease
- sickle-shaped RBC clump and less O2 distributed
- life expectancy 14 years
- die of blood clots, heart/kidney failure
- African Americans have recessive genes/are carriers
- 50% chance having child with sickle cell anemia
11
Q
prenatal screening methods (5)
A
- utltrasound - visual image of fetus
- amniocentesis - sample of amniotic fluid
- chorionic villus sampling - extract hair cells around fetus
- maternal blood sampling - blood cells entered mom via placenta
- preimplantation genetic diagnosis - check DNA of first cells
- Huntington’s disease single dominant gene
- strikes mid-life
- slurred speech, erratic walking
- irritability, moodiness, dementia, loss of cognitive abilities
12
Q
gene-environmental interplay (5)
A
- genes turning on/off throughout lifespan
- environmental influences impact from conception to death
- unique genes exert themselves as become adults
- don’t ask how much of genes but rather heredity and environment work together
- genes do not determine anything but rather provide potential
