Genetics Flashcards
DNA
A double helix made of nucleotides, the molecule that determines the genetic characteristics of most living things
Chromosome
Thread-like structures in the nucleus composed of DNA and proteins, contains the genetic information in the form of genes
Gene
A section of DNA that carries the genetic code for a particular characteristic
Alleles
Different forms of the same gene
Nucleotide
The building blocks of DNA. Contains a sugar, phosphate and a base - Adenine, Thymine, Guanine and Cytosine
Adenine
Nitrogen rich base, forms pair with Thymine
Thymine
Nitrogen rich base, forms pair with Adenine
Guanine
Nitrogen rich base, forms pair with Cytosine
Cytosine
Nitrogen rich base, forms pair with Guanine
Mitosis
Cell division for growth and repair. Produces 2 identical daughter cells to the parent
Interphase
Has 3 stages - G1, S and G2. G1 is cell growth, S is DNA replication, and G2 is the cell preparing for cell division. A cell spends most of its time in G1
Prophase
First part of Mitosis. The nucleus disappears and the chromosomes condense
Metaphase
Second part of Mitosis. The chromosomes line up in the middle of the cell.
Anaphase
Third part of Mitosis. The duplicated chromosomes split and the sister chromatids are pulled away from each other.
Telophase
Last part of Mitosis. The cell begins to split, nucleus starts to reform and the chromosomes start to unwind.
Cytokenesis
2 identical daughter cells are produced that are identical to their parent.
Sister chromatid
A duplicated chromosome
Meiosis
Type of cell division that produces sex cells for sexual reproduction. Results in 4 haploid daughter cells.
Gamete
Sperm and egg cells
Fertilization
When a sperm and egg combine to make an offspring
Zygote
The cell formed by fusion of the two gametes
Phenotype
The characteristic that we observe
Genotype
The combination of alleles
Dominant
The trait that you see when either type of allele is present
Recessive
The trait you see only when both alleles are the same
Incomplete dominance
When both alleles are dominant so both are expressed in the heterozygous phenotype. Results in a smooth blend.
Codominance
When both alleles are dominant so both are expressed in the heterozygous phenotype. Results in a spotty blend.
Purebreed
Another word for homozygous
Hybrid
Another word for heterozygous
Carrier
Someone who is heterozygous with traits that are recessive. Someone who can pass on a trait without displaying it
Pedigree
O = female
◻ = male
● = affected female
◼ = affected male
▣ = male carrier
◻-O = couple
◻-O = non identical twins
O-O = identical twins
Autosomal dominant
An affected individual must have an affected parent
Autosomal recessive
Affects O and ◻ equally and skips a generation
X-linked dominant
Affected males must have an affected mother and an affected father will pass the condition on to all daughters
X-linked recessive
Affected females must have an affected father. Males can be affected if neither parent has condition.
Haploid
1 set of chromosomes, 23 chromosomes. Usually a gamete.
Diploid - D means 2
2 sets of chromosomes, 23 pairs of chromosomes so 46. Usually a normal cell.
Autosomal
Any inheritance with your autosomal chromosomes
X-linked
Disorder on sex chromosome. Males cannot be carriers.
Heterozygous
Different alleles
Homozygous
Same alleles
Karyotype
Visual representation of the complete set of chromosomes in a cell in order of size from largest to smallest. Is numbered; 1 is the largest. There are 22 pairs of autosomal chromosomes and 1 part of sex chromosomes.
Autosome
One of the numbered chromosome in a karyotype.
“A” homozygous blood type
AA alelle
“A” heterozygous blood type
Ai allele
“B” homozygous blood type
BB allele
“B” heterozygous blood type
Bi allele
“O” homozygous blood type
ii allele - O is recessive
