Bio Test #1 Flashcards
Where is DNA located?
DNA is located in the nucleus of the cell, found in the chromosome
Is everyone’s DNA the same?
All DNA is different except for identical twins
What does DNA stand for?
It stands for Deoxyribonucleic Acid
How many chromosomes are there?
23 pairs of chromosomes found in the nucleus. If there are extra or less then that causes a genetic mutation such as down syndrome
What are traits
A trait is a distinguishing quality. There exists a variation of traits among members of a species. Sometimes some traits show up more frequently in populations
What are traits controlled by?
Genes
Where are genes found?
A gene is a segment of DNA (loci) found in chromosomes in the nucleus of a cell
What is a gene
A sequence of DNA that encodes your traits
Genetics are influenced by… Examples…
They can be influenced by parents or the environment. Skin tone, freckles, hair color, allergies
Are all traits observable?
Some are, some aren’t. some non observable ones include: asthma, disease risk, diabetes
Traits are influenced by…
both genetics and environment
What are the layers of the nucleus (DNA)
Gene -> DNA -> Chromosome -> Nucleus -> cell
Definition of heridity
The passing on of genetic traits from parent to offspring
Alleles:
Alternative forms of a gene that encodes for different traits
Types of alleles:
Homozygous - alleles are the same
Heterozygous - alleles are different
Example of gene + allele combo:
gene: eye color
allele: blue, brown, green, grey
Gene: hair color
allele: blond, red, brown, black
Phenotype:
The observable characteristics of a trait
Genotype:
The allele combination for a specific trait (letter)
There are three types of alleles…
Homozygous Dominant (B,B)
Homozygous Recessive (b,b)
Heterozygous (B,b)
Dominante allele over recessive
What did Gregor Mendel do?
Mendel cross pollinated pea plants by removing the stamens from one pea plant and manually using pollen from another pea plant to fertilize the original one.