Unit Five: Heredity

Heterozygous

An organism that has two different alleles for a trait, Bb

Homozygous

An organism that has two identical alleles for a trait, BB or bb

Mitosis

Cell division in body cells that creates 2 identical diploid cells (1 division, PMAT)

46 -> 92 -> 46, 46

Meiosis

Cell division that produces 4 different haploid gametes (two divisions, PMAT)

46 -> 92 -> 46, 46 -> 23, 23, 23, 23

Gametes

sex cells (sperm and egg)

somatic cells

body cells (liver cells, heart cells)

haploid cell

A cell containing only one set of chromosomes (n).

Diploid

2 sets of chromosomes

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

Chromosomes

threadlike structures made of DNA molecules that contain the genes

Genes

DNA segments that serve as the key functional units in passing traits .

Karyotype

A picture of all the chromosomes in a cell arranged in pairs

Traits

A characteristic that an organism can pass on to its offspring through its genes.

gene expression

Genetic information in a gene changed to messenger RNA and then to a protein

Levels of organization

nucleotide --> gene --> DNA --> chromosome --> nucleus

Nucleotide

Building block of DNA ladder; made up of sugar, phosphate, and base (ACTG)

nitrogenous base

A, C, T, G

double helix

Shape of DNA; two complementary strands spiraled together

DNA

Instructions for making proteins

Zygote

Product of fertilization, when sperm and egg fuse (2N)

Fertilization

Sperm entering egg and producing a zygote

embryo

Organism in the early stages of development

Cell differentiation

When cells are assigned their jobs (can no longer be any type of cell)

Stem Cell

Pluripotent cell; cell that can become any type of cell (e.g., blood cell, muscle cell, etc.)

mitosis and meiosis similarities

1) Start 1 diploid (2N) cell, 2) Go through PMAT, 3) start w/ 1 round DNA replication

Genotype

Genetic makeup of organism (e.g., BB, homozygous)

Phenotype

An organism's physical appearance, or visible traits.

Allele

Different forms of a gene

Dominant Trait

Trait that is shown in every generation

Recessive Trait

Trait that skips generations OR shows carriers

Sex-linked Trait

Trait that affects more males than females; only females can be carriers

Autosomal Trait

Normal trait that affects equal females and males or more females

Pedigree

Family tree that shows a traits inheritance pattern

Mutations

errors in DNA replication or from environmental factors

Variation

differences

Genetic Information in DNA / RNA

Nucleotides

Transcription

DNA to mRNA; occurs in the nucleus

Translation

mRNA to protein; occurs in the ribosome in the cytoplasm

Amino acid

Building block of protein

DNA Replication

Copying of DNA molecule using its complementary strands; DNA unzips

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

incomplete dominance

Offspring is a mixture of the parent's characteristics through multiple generations

Codominance

offspring contains BOTH parent's characteristics distinctly