Chapter 9 Flashcards
The scientific study of heredity.
Genetics
The transmission of traits from one generation to the next.
Heredity
Who was the first to study genetics?
Gregor Mendel
Gregor Mendel
was the first to study genetics, and did this by observing patterns of inheritance in pea plants
Organisms are composed of combination of many different _____.
traits
Some traits are common, and are referred to as ____________, while others may be rare or unusual.
wild type trait
The reason why we see such differences is because____________________________.
individuals may posses variation of each gene
Offspring inherit these genetic variations from their parents, incorporating their parents genetic information in the offspring ________.
Genome
The overall appearance of an organism is called its __________.
Phenotype
The phenotype includes.
all visible characteristics of an organism, including its physiology
An organisms genetic makeup is called.
Genotype
The genotype is all of the organisms.
genes and their exact DNA composition
Genes exit at specific position on the chromosomes called?
Gene locus (pl.loci)
Mendal studied __________.
Garden peas
Pea plants
have variety of easily observed traits
they are easily manipulated
they are normally self fertillized
Mendals experimental treatments consisted of ____-______ plants with different traits.
Cross-fertilizing
Mendals found true-breeding (purebred) individuals and crossed them to create________.
hybrids
Genes have different versions, which we call _____.
Alleles
Diploid organisms have __ pair (_) alleles for a given gene.
1
2
Each egg carries __ copy of each _____. and each sperm also carriers____ copy of each _____.
1 allele
1 allele
Once sperm and egg fuse, the newly fertilized egg (zygote) has 2 copies of each allele and is therefore called?
Diploid
What is a diploid?
has 2 copies of each allele. these copies can be identical or different verison of each allele
If an allele is different what happens?
the dominant allele masks the the recessive allele and is expressed.
A ________ is a cross between organisms that differ in only 1 trait.
Monohybrid cross
An explanation of a monohybrid cross using a __________.
punnet square
a upper case letter is used to express what?
dominant traits