Genetic information Flashcards
What is DNA?
Deoxyribonucleic acid is a molecule that consists of three smaller molecules: a phosphate group, a sugar (deoxyribose), and a nitrogenous base.
What is an allele?
Each form of a gene is called an allele.
Where is genetic information stored?
Genetic information is stored in sequences of DNA molecules within the nucleus of cells of an organism.
Do all cells in multicellular organisms contain the same genetic information?
Yes, in multicellular organisms all cells contain the same information within their nuclei.
How is genetic information passed during reproduction?
Genetic information is passed from parent to child.
What does genetic information determine for each organism?
It determines:
* Traits/types of traits an organism will possess
* Abilities of an organism
What is the structure of a DNA strand?
Each strand consists of a backbone with alternating sugar-phosphate molecules and complementary paired nitrogenous base molecules.
Which nitrogenous bases pair together in DNA?
Adenine pairs with thymine and guanine pairs with cytosine.
How is DNA organized within the cell nucleus?
Individual strands of DNA are wrapped around proteins called histones.
What is a chromosome?
A DNA strand wrapped around several histones is called a chromosome.
What do both chromosomes in each pair possess?
Both chromosomes possess the same genes along their length.
How many pairs of chromosomes do humans have?
Humans have twenty-three pairs of chromosomes.
What determines the gender of an individual?
The twenty-third pair of chromosomes determines gender:
* An XX combination results in a female
* An XY combination results in a male
What is a gene?
A segment that represents a trait within an organism is called a gene.
In sexually reproducing organisms, how do chromosomes come?
Chromosomes come in pairs: one from the father and one from the mother.
Fill in the blank: A segment of nucleotides that codes for traits within an organism is called a _______.
gene
