Chromosomes, Genes, Alleles and Traits

Question 1

what is a gene

Answer 1

a sequence of DNA that codes for a protein

Question 2

what are genes

Answer 2

• basic units of heredity
• some genes control other genes

Question 3

what are alleles

Answer 3

• different versions of the same gene
  example: the eye colour gene has a protein that gives one person blue eyes but has a different protein that gives another person brown eyes

Question 4

what do alleles do

Answer 4

• code for different versions of the same protein which can affect the body differently

Question 5

what is a homozygous

Answer 5

someone who has two of the same alleles

Question 6

what is heterozygous

Answer 6

someone who has two different forms of an allele

Question 7

how do genes control characteristics that the offspring will have

Answer 7

• a certain sequence of bases will produce one type of protein while another sequence will produce another type

Question 8

what do proteins affect

Answer 8

• each protein has an affect on the function of a cell
• the function manifests as traits

Question 9

how do genes produce proteins

Answer 9

1. all cells have a nucleus
2. all nuclei have DNA
3. look at the DNA and make an mRNA copy of it
4. then use the mRNA to make a template to make new proteins

Question 10

what does DNA do before proteins are made

Answer 10

• DNA makes a copy of itself
• instead of making a complementary DNA strand it makes a complementary RNA strand

Question 11

what is the complementary RNA strand called

Answer 11

• mRNA
• messenger RNA