Biology: Chap 9 Genetics

Flashcards for reviewing genetics lecture notes, focusing on key vocabulary.

Male

Makes more numerous smaller gametes; in humans, sperm.

Female

Makes fewer larger gametes relative to the male; in humans, eggs.

Sex Determination

The biological process of determining sex.

Sex Differentiation

The steps that happen for sex determination to occur.

XY System

A sex determination system where sex is determined by the presence of X and Y chromosomes.

Somatic Chromosomes

The first 22 chromosomes; everyone gets two of each.

Autosomes

Genes that are not sex-linked

X Chromosome

A large chromosome with some genes, present in biological males.

Y Chromosome

Small chromosome in biological males containing the SRY gene.

SRY Gene

A single gene on the Y chromosome that activates early in embryonic development and causes a cascade of effects to make the individual biologically male.

Female (Chromosomally)

Chromosomally characterized by two X chromosomes and no Y chromosome.

Temperature-Dependent Sex Determination

A sex determination system where sex is determined by the incubation temperature of the eggs.

Hymenopter

A type of insect in which sex determination occurs this way; includes ants, bees, and wasps.

Haplodiploid Sex Determination System

A sex determination system where sex is determined by the number of chromosome sets; diploid are female, haploid are male.

Diploid

Has two sets of chromosomes.

Haploid

Has one set of chromosomes.

Workers (Honeybees)

Sterile females; forced into not developing fully by chemical from the queen bee; perform labor in the colony.

Blending Inheritance

The incorrect way in which people thought about inheritance, states that the offspring is a combination of both parents.

Particulate Inheritance

The correct way of genetics, states that what we inherit are discrete bits of information.

Genes

Discrete bits of information that we inherit.

Character

A feature in a population that is different in the population, there is a difference, and that difference is inheritable to some degree.

Trait

The actual difference in genetics.

Simple Trait

Controlled by one gene and there is little to no environmental effect.

Complex Trait

Controlled by multiple genes and has a large environmental impact.

P One Generation

A population, the first parental generation

F One Generation

The first filial generation, the first generation of offspring.

Monohybrids

A hybrid of the yellow plants and the green plants.

Monohybrid Cross

Crossing hybrids with each other.

F Two Generation

The second population (offspring) of plants.

Phenotype

The trait the organism has in a genetics context.

Gene

The genetic factor that controls a character.

Allele

Variation of a gene.

Genotype

All the alleles that an organism has.

Dominant Allele

The yellow allele covers it up.

Recessive Allele

In the case where you have two different copies of the gene, two different alleles. When you look at the organism, you see that the dominating allele covers up(masks or hides) this allele.

Homozygous Dominant

The individual has two copies of the dominant allele.

Homozygous Recessive

The genotype with two copies of the recessive allele.

Heterozygous

One copy of the dominant allele, one copy of the recessive allele, if the copies of the gene are different

Law of Segregation

The copies of the genes separate into different gametes.

Dihybrid

A hybrid of two different characters, a hybrid of two different genes.

Parental Phenotypes

The same phenotypes as in the p one generation.

Recombinants

A mix and match of the traits.

Capital(letter)

The letter given to the dominant allele.

Lowercase(letter)

The letter given to the recessive allele.

Independent Assortment

The genes segregate in the gametes independently of each other.