CYTOGENETICS L3, INHERITANCE PRELIMS

What governs how genetic information is transmitted from generation to generation

The patterns called principles of inheritance

What phrase refers to the concept of kind in inheritance

After his kind

What is inheritance not

Subtyping

Who is the Father of Modern Genetics

Gregor Mendel

What was Gregor Mendel's profession

Austrian Monk, a creationist

When did Mendel publish his law

1865

How long did Mendel's work go unnoticed

35 years

Who rediscovered Mendel's laws in the Netherlands

Hugo De Vries

Who rediscovered Mendel's laws in Austria

Erich Von Tschermark

Who rediscovered Mendel's laws in Germany

Carl Correns

What is the Law of Dominance

Each trait is determined by two factors (alleles), one from each parent, and dominant alleles mask recessive ones

What are the three types of allele expression in the Law of Dominance

Dominant, co-dominant, recessive

What is the Law of Segregation

The two alleles of a gene are never transmitted together from one parent to an offspring

What happens during meiosis according to the Law of Segregation

Alleles segregate into separate gametes

What explains variation in inherited characteristics

Alternative versions of genes or alleles

How many alleles does an organism inherit per trait

Two, one from each parent

What happens if the two alleles differ

The dominant is fully expressed, the recessive has no noticeable effect

What do the two genes for each character do during gamete production

Segregate

What is the Law of Independent Assortment

Alleles of different genes pass randomly to offspring

What separates independently in the gametes

Alleles for different genes

What effect does one trait have on the emergence of another

None

What does Mendel conclude about expressed phenotypes

Each organism carries two copies

What happens when one phenotype differs from the other

One will dominate the other

What is a known exception to the Law of Independent Assortment

Genes very close together on a chromosome pass down together

What is genotype

The genetic makeup of an organism

What is phenotype

The external appearance of an organism caused by genotype

What is a gene pool

All genes and their alleles present in a population

What is a genome

Entire genetic material of an organism

What is a hybrid

An organism that receives different alleles for a trait from each parent

What are genes composed of

DNA (deoxyribonucleic acid)

What do DNA nucleotides code for

Proteins in the human body including enzymes and structural proteins

What was the estimated number of human protein-coding genes in 2001

Between 25,000 and 35,000

What are alleles

Different forms of a trait, one form of a gene

How are most traits determined

By multiple genes with multiple alleles

What is locus

Location of a specific gene on a chromosome

What is a dominant gene

Fully expressed gene with full control on the phenotype

What is a recessive gene

Completely masked in the phenotype

How are dominant alleles denoted

Capital letter (A)

How are recessive alleles denoted

Lowercase letter (a)

What determines blood phenotype

Antigen on surface of red blood cell

What antigen does Group A have

A antigen

What antigen does Group B have

B antigen

What antigens does Group AB have

A and B antigens

What antigens does Group O have

None

What antibodies does Group A have

Anti-B

What antibodies does Group B have

Anti-A

What antibodies does Group AB have

None

What antibodies does Group O have

Anti-A and Anti-B

What is the dominance relationship of blood types

O is recessive; A and B are dominant; AB is co-dominant

What are the genotypes for Type A

AO (Heterozygous A), AA (Homozygous A)

What are the genotypes for Type B

BO (Heterozygous B), BB (Homozygous B)

What is the genotype for Type O

OO

What is the genotype for Type AB

AB

What antigen and antibodies does Type A have

A antigen, Anti-B antibodies

What antigen and antibodies does Type B have

B antigen, Anti-A antibodies

What antigen and antibodies does Type O have

None, Anti-A and Anti-B antibodies

What antigen and antibodies does Type AB have

A and B antigens, None

What is an autosomal gene

A gene on one of the 22 pairs of autosomes (non-sex chromosomes)

What is an autosomal trait

A trait or disease associated with an autosomal gene

What are the two types of autosomal traits

Dominant and Recessive

Who is equally likely to inherit autosomal conditions

Males and females

What is autosomal dominant inheritance

A single copy of an allele is enough to be expressed in the phenotype

What kind of individuals express autosomal dominant conditions

Heterozygotes

What is autosomal recessive inheritance

Requires 2 copies of the allele to express the phenotype

Where are genes for autosomal recessive traits located

On autosomes

Why does expression not occur with one normal allele

It is sufficient to prevent expression of the disease

What is the female chromosome composition

XX

What is the male chromosome composition

XY

How many genes does the Y chromosome have compared to the X

Very few

What is X-linked inheritance also called

Sex-linked inheritance

Why is there no male-to-male transmission in X-linked inheritance

Father gives Y, not X, to sons

What happens to daughters of an affected father in X-linked dominant

All daughters are affected

What happens to sons of an affected father in X-linked dominant

None are affected (unless mother is also affected)

If a son is affected in X-linked dominant, what can be said about the mother

She is also affected

Who is affected in X-linked recessive inheritance

Males (hemizygous) and homozygous females

What usually happens to carrier females in X-linked recessive inheritance

They do not express the phenotype

What does mitochondrial inheritance refer to

Additional genes in cell's mitochondria

Who transmits mitochondria to children

The mother (through the egg)

What is the hallmark of mitochondrial inheritance

Transmission from affected woman to all her children