Genetics - FINAL TERM BIOLOGY

Diploid (2n)

A sexually produced _____ organism is a result of the union of a haploid egg cell (n) and a haploid sperm cell (n).

46

In humans, this is the normal diploid number of chromosomes.

23

The number of chromosomes inherited through a human sex cell.

Appearance; Behavior; Physiological processes

Chromosomes carry all the characteristics that will define the _____, ______, and _____ of the resulting organism.

Science of Genetics

Studies how characteristics are inherited.

Science of Genetics

Addresses how other differences or variations occur in offsprings as a result of environmental and other nongenetic factors.

Chromosome

Made up of DNA molecules coiled around histones.

Histones

Sequence of DNA bases

The _____ in a chromosome will determine the codes of proteins responsible for the observable characteristics of an individual.

Gene

Describes the specific sequence of DNA containing the information codes for protein.

Genome

The set of genes found in a cell responsible for the characteristics of an individual.

Paternal and maternal sets

In sexually reproducing organisms, the genome is composed of two sets of chromosomes, _____.

Pair

In a diploid (2n) individual, every chromosome is in _____.

Homologous chromosomes

Refer to a pair of paternal and maternal chromosomes that are of the same size, similar gene locations, common banding patterns, and the same centromere location.

Loci/Locus

Location of a gene on a chromosome.

Human chromosome 1

Contains 249 million DNA base pairs with roughly around 2000 genes.

Alleles

One of two or more alternative forms of gene.

Mitosis

Meiosis

When a diploid cell containing the homologous chromosomes undergo _____, the alleles are separated, forming haploid cells.

Genotype

The totality of the genetic makeup of an individual.

Genotype

The combination of alleles found in a homologous chromosome.

Phenotype

Refers to the observable expression of particular genotype.

Homozygous

When two similar alleles are present in a pair (such as BB or bb).

Heterozygous

When two different alleles are paired (such as Bb).

Dominant Allele

The allele that is expressed in a heterozygous condition.

Recessive Allele

The allele that is NOT expressed in a heterozygous condition.

Gregor Johann Mendel

Father of Genetics.

Gregor Johann Mendel

An Augustinian monk who discovered the basic principles of heredity through experiments in his garden.

Pisum Sativum/Garden Pea

Monohybrid Cross

A cross involving a single trait or one trait inheritance.

Unit factors in pairs

The genetic characters are controlled by unit factors that exist in pairs in individual organisms.

The Principle of Dominance and Recessiveness

When two unlike factors responsible for a single trait are present in an individual, one unit factor is dominant over the other, which is said to be recessive.

The Principle of Dominance and Recessiveness

"One factor in a pair may mask the expression of the other."

The Law of Segregation

During the formation of gametes, the paired unit factors segregate randomly so that each gamete receives one or the other with equal likelihood.

Gene pair

"A _____ carries two separate characteristics."

Law of Independent assortment

During gamete formation, segregating pairs of unit factors are assorted independently of each other. The inheritance of one trait is not affected by the inheritance of another trait.

Law of Independent assortment

"During gamete formation, the gene pair assorts independently."