Genetics & Evolution Flashcards
What is DNA?
Known as (deoxyribonucelic acid) Stores all genetic information Determines characteristics Instructs how to build every protein Structure double helix (twisted ladder)
What are the 4 DNA bases?
Adenine Cytosine Guannine Thymine “Apple in Trees.” “Car in Garage”
Nucelotides?
DNA molecule
Sugar, phospahte & base
Opposite side is flipped upside down
Amino acids & protein?
Sequence of 3 bases=triplet
most triplet codes are for amino acids
Sequence of amino acids=proteins
Enzymes
= protein that act as catalysts within living cells. Catalysts increase the rate at which chemical reactions occur without being consumed or permanently altered themselves.
chemical reaction occurs multiple times
Antibodies
=Y-shaped proteins that are produced by the immune system to help stop intruders from harming the body.
Hormone
=A chemical substance produced in the body that controls and regulates the activity of certain cells or organs
Cellular product
What is a gene?
A unit of heredity which is transferred from a parent to offspring and is held to determine some characteristic of the offspring.
What is an allele?
Analleleis one of the possible forms of a gene. Most genes have twoalleles, a dominantalleleand a recessiveallele. e.g 9( Aa / AA / aa)
Genotype?
Genetic makeup
What alleles you have
Phenotype?
The appearance
What is a chromosome?
A structure in all living cells that consists of a single molecule of DNA bonded to various proteins and that carries the genes determining heredity
DNA tightly coiled many times around proteins called histones
22 autosomal 1 sex-linked (mitosis, meiosis)
Mitosis?
Body cells produce new cells
2 identical daughter cells
Have same n.o of chromosomes as parent cells
Diploid
(2n) = 46 chromosomes
Diploid= 2 sets of chromosomes each set given by father and mother
Body cells= somatic
Meiosis?
Forms gametes, 4 offspring (non-Identical) Egg & sperm=sex cells N.o of chromosomes is halved Haploid=23 (n) 2 successive cell divisions
Haploid
N.o of chromosomes is halved
Haploid=23 (n)
Cell Cycle?
DNA synthesis (interphase), Mitosis or Meiosis then Cytokinesis
Homozygous?
Pure breeding
Identical alleles for a single trait.
E.g (AA / aa)
Heterozygous?
Contains two different alleles of a gene
Hyrbrid
(one wild-type allele and one mutant allele)
E.g (Aa)
Gregor Mendel Contributions?
First person to predict how traits are transferred from one generation to the next.
Studied pea traits
Used pure breeding
Punnett Square
Recessive Traits?
The trait only shows if the individual has two copies of that allele.
E.g the allele for blue. eyes is recessive. You need two copies of the allele to have blue eyes.
(bb)
Dominant Traits?
The trait always shows, even if the individual only has one copy of it (one allele for it).
E.g Brown eyes is more dominant over blue (BB, Bb)
Automal?
44 autosomes in body cells
Matched into pairs from 1-22
Sex-linked inheritance?
The other 2 chromosomes are sex chromosomes Females posses XX Can have disorder and also be carrier Males posses XY The Y doesn’t carry any genes Have the disorder or not Y determines gender