unit 3

Question 1

Deoxyribonucleic acid (DNA) is a molecule made up of nucleotides that contains genetic information for cell growth, division and function.

Answer 1

DNA

Question 2

A gene is a segment on a chromosome that determines a specific trait. Genes are the units of heredity

Answer 2

Gene

Question 3

a different form or version of a gene usually occur in pairs

Answer 3

allele

Question 4

a gene variant that is expressed more strongly than other versions of the same gene - the dominant allele masks the effect of the recessive allele

Answer 4

dominant

Question 5

a gene that is masked by a dominant gene, and is only expressed when two copies of the gene are present

Answer 5

recessive

Question 6

the genetic make up or code of an organism - Ex: BB, Bb, bb

Answer 6

genotype

Question 7

the observable traits or physical appearance of an organism - Ex: brown eyes or blue eyes

Answer 7

phenotype

Question 8

If an organism has two of the same kind of gene for a trait, it is called pure or homozygous.
Example: Homozygous brown eyes (BB) ~ Homozygous blue eyes (bb)

Answer 8

homozygous

Question 9

An organism with two different alleles for a trait is called heterozygous or hybrid.
Example: A heterozygous tall plant (Tt) expresses the dominant allele (T or tall) and thus, is tall

Answer 9

heterozygous

Question 10

A group of living things that can reproduce and have offspring.

Answer 10

Species

Question 11

The preserved remains or traces of ancient organisms found in rocks.

Answer 11

Fossil