Genetics

Heredity

T the passing of traits from one generation to the next. To understand heredity we have to observe individual organisms.

Genetics

the study of how genes are inherited

Genes

a section of chromosomes that contain information for a particular trait. A section of base pairs

Genotype

the combination of genes for a trait. The genotype is the genetic code or “blueprint.” A genotype is heritable, meaning parents pass genes on to their offspring.

Phenotype

the outward physical appearance of the gene combination. Phenotype is the physical expression of the genotype, but environmental factors also affect it.

1. For example, many flamingos are pink, while some are not, even if they have the same genotypes for feather color. This is because feather color depends on the flamingo’s diet. Phenotype is the physical expression of the genotype, but environmental factors also affect it.

Variation/Allele

one or two alternate forms of a gene.  skin color, eye color, hair color, blood type

Heredity

passing of genes from parents to offspring. (e.g. color blindness, curly hair, hand clasping, hairline shape, freckles, tongue rolling, earlobe attachment)

Inherited trait

traits controlled by genes from parents

Acquired trait

Acquired trait- traits influenced by the environment. It may be acquired due to his own activities or external influence. Unlike inherited traits, acquired traits cannot be genetically passed on to the next generation. Example, the ability to dance, cook well etc.

Hybrid

an organism that has one dominant allele and one recessive allele (wholpin, zebroids, hinny, ligers)

Heterozygous

when two different genes are present

Purebred

organisms that have two of the same allele

Homozygous

when two of the same genes are present

Mutations

a change or errors in DNA code. Mutations can appear as  Substitutions, deletions, insertions, inversions

Dominant

the stronger allele that hides the recessive allele (Cruly hair is stronger than straight; A & B blood types are dominant over the O blood type)

Two Base Pairs

1. A/T

2. C/G

Recessive

the weaker allele that is masked by the dominant one. straight hairlines, attached earlobes, and left-handedness. Cystic fibrosis, sickle cell anemia

Nitrogen Based Pairs

The sequence order of nitrogenous bases in DNA form the code for making proteins.  Nitrogenous Based pairs are (A/T or T/A) and (C/G or G/C). A;: Adenine , T: Thymine, G: Guanine; C: CytosineThe nitrogenous base pairs consist of complementary pairs: adenine pairs with thymine, and cytosine pairs with guanine. These pairings are crucial for the structure of DNA and the encoding of genetic information.

Hydrogen bonds

hold pairs together

Base sequence

Order of nitrogen bases in a DNA molecule.

Proteins

help perform life processes.

Deoxyribonucleic acid

genetic material in organisms

Chromosomes

tightly coiled DNA strands

Double helix

the shape of two strands of DNA when bonded together.

Sugar-phosphate backbone

makes up the sides of the DNA ladder

Genome

An organism’s complete set of DNA, including al lof its genes

Replication

Copying DNA important for cell division (mitosis) and reproduction

Gene

A section of a chromosome that contains information for a particular trait

Nucleus

organelle in a eukaryotic cells that stores genetic information