part 3 Flashcards
Gene
A gene is a short stretch of DNA that codes for a characteristic.
Genome
A genome is all the genetic information an individual possesses within their DNA.
Genotype
A genotype is the alleles an individual carries within their genes.
Autosomes
Autosomes are all the chromones except for the X/Y chromosome.
X-linked versus Y-linked genes
X-linked genes determine sex, while Y-linked genes control characteristics unrelated to sex. Sons and daughters have an equal probability of inheriting a recessive allele of an X-linked genetic disorder from their mother, but only the sons can inherit Y-linked genetic disorders from their father.
Sickle cell anemia
Sickle cell anemia is caused by one single-base substitution mutation (GLU to VAL). The new shape of the sickled red blood cells causes them to clump together easier and clog blood vessels.
Oncogene
Oncogenes are mutated genes that can transform into tumors if “turned on”.
Haploid versus diploid cells
Haploid cells have one copy of each chromosome (non-homologous, I I I), whereas diploid cells have two copies of each chromosome (homologous, II II II).
Amniocentesis
Amniocentesis is a prenatal test that takes amniotic fluid from the uterus, around an individual’s baby to test if the baby has certain health conditions.
Chorionic villus sampling
Chorionic villus sampling is a prenatal test that takes a sample of tissue from the placenta to test if the individual’s baby has any genetic or chromosomal conditions.
What happens during MITOSIS (prophase, metaphase, anaphase, telophase)?
Mitosis produces two genetically identical daughter cells from a single parent cell. PROPHASE: Chromosomes condense forming two chromatids. Nuclear membrane disintegrates causing the spindle to form. METAPHASE: Spindle organizes condensed chromosomes on the equator of the cell. Some spindle fibers attach to the centromeres and some span the cell. M-checkpoint occurs. ANAPHASE: Some spindle fibers shorten which pull the chromatids apart. Some spindle fibers lengthen which cause cell to elongate. TELOPHASE: Two new nuclei form
Miller-Urey experiment
The Miller-Urey experiment simulated the conditions of early-Earth. The experiment showed that biological molecules that are essential for life can be synthesized abiotically from simpler substances.
Binary fission
Binary fission is a type of asexual reproduction that involves a parent cell dividing, resulting in 2 identical cells. The process starts with the parent cell preparing for reproduction by replicating the DNA. Then, the 2 DNA molecules each attach to a different part of the cell membrane and build more membrane to elongate the cell. Then, the cells successfully divide.
Outline MEIOSIS I (prophase I, metaphase I, anaphase I, and telophase I)
Meiosis produces 4 cells containing half of the original amount of DNA from the parent cell, which divides twice. PROPHASE I: Nuclear membrane dissolves, spindle fibers start to undergo crossing over. METAPHASE I: Paired chromosomes line up at the equator of the cell, a spindle fiber attaches to each pair. ANAPHASE I: Spindle fibers pull the paired chromosomes apart. TELOPHASE I: Paired chromosomes arrive at opposite poles of the cell and nuclear membrane may reform.
Outline MEIOSIS II (prophase II, metaphase II, anaphase II, telophase II)
Meiosis produces 4 cells containing half of the original amount of DNA from the parent cell which divides twice. PROPHASE II: Nuclear envelope breaks, spindle fibers form between centrosomes. METAPHASE II: Unpaired chromosomes line up at the equator of the cell. ANAPHASE II: Unpaired chromosomes separate and are pulled to opposite poles of the cell. TELOPHASE II: Nuclear membranes begin to reform around new chromosomes, chromosomes decondense.
