Homeotic Genes and Body Patterns Quiz

What do homeotic genes specify during embryonic development?

• The diet of the organism

• The color of the organism

• How structures develop in different segments of the body

• The lifespan of the organism

What are homologous genes?

• Genes that determine the color of an organism

• Genes that are only found in fruit flies

• Genes that share similar sequence and function in different organisms

• Genes that are identical in all organisms

What is the homeobox?

• A type of cell found in embryos

• A stretch of about 180 bases shared by homeotic genes

• A segment of the thorax in fruit flies

• A protein that binds to DNA

What is the function of Hox proteins?

• To replicate DNA during cell division

• To attach to molecular switches on DNA, turning other genes on and off

• To transport nutrients across cell membranes

• To provide energy to cells

What is the significance of Hox genes in evolutionary biology?

• They are responsible for photosynthesis

• They provide clues about evolutionary relationships

• They are only found in mammals

• They are unique to vertebrates

What happens when Hox gene activity in the third segment of a fruit fly is made the same as that in the second?

• The fly grows an extra pair of eyes

• The fly's lifespan is reduced

• Both segments grow legs and wings

• The fly becomes sterile

What is the role of Hox genes in vertebrate development?

• They determine the color of the skin

• They help specify the difference between an arm and a leg

• They are responsible for the organism's immune response

• They control the organism's metabolism

What is the result of inactivating Hox10 paralogs in mice?

• The mice lose their sense of smell

• The mice develop extra limbs

• The vertebrae of the lower back grow ribs

• The mice become colorblind

What is the process called when a single ancestral gene is duplicated and takes on different functions?

• Transcription

• Duplication and divergence

• Gene splicing

• Translation

How do Hox genes affect the identity of vertebrae in vertebrates?

• They determine the color of the vertebrae

• They direct segments to grow ribs or bones that fuse together

• They control the size of the vertebrae

• They are responsible for the vertebrae's ability to heal