20.1 Variation and Inheritance

Question 1

Chlorosis

Answer 1

Pale or yellow leaves
Cells do not produce enough chlorophyll
Limits photosynthesis

Question 2

Environmental factors causing chlorosis

Answer 2

Lack of light - plants reduce chlorophyll production to save resources
Mineral deficiencies - low in Iron or Magnesium
Virus infections - viruses interfere with metabolism of cells

Question 3

Genetic factors affecting obesity

Answer 3

Could be a gene mutation that causes unusual pattern of fat deposition

Question 4

Genotype

Answer 4

Genetic make up of an organism related to that gene

Question 5

Phenotype

Answer 5

Observable characteristics of an organism

Question 6

Dominant allele

Answer 6

Version of a gene that will always be expressed if present in an organism

Question 7

Recessive allele

Answer 7

Version of a gene that will only be expressed of two copies are present in an organism

Question 8

Homozygous

Answer 8

2 identical alleles for a characteristic

Question 9

Heterozygous

Answer 9

2 different alleles for a characteristic

Question 10

Continuous variation

Answer 10

Characteristic that can take any value in a range
Genetic and environmental variation
Polygene control

Question 11

Discontinuous variation

Answer 11

Characteristic that can only appear in specific or discrete values
Mostly genetic variation
Controlled by one or two genes