Part A Which of these statements are both true and support t

Part A

Which of these statements are both true and support the endosymbiosis theory?

Select all that apply.

Most mitochondrial genes are transcribed unidirectionally.

Part B

This phylogenetic tree (pictured below) shows the evolutionary history of eukaryotic organisms that contain mitochondria and chloroplasts.

Use the tree to determine which statements regarding the origins of these organelles are true.

Select all that apply.

Mitochondrial genes are transcribed by a polymerase that is similar to bacterial polymerases.

Organelle DNA packaging is similar to the packaging of a bacterial chromosome.

Many mitochondrial genes are polycistronic.

Organelle DNA packaging is similar to nuclear DNA packaging.

Mitochondria are similar in size to some existing bacteria.

Most mitochondrial genes are transcribed unidirectionally. Part B This phylogenetic tree (pictured below) shows the evolutionary history of eukaryotic organisms that contain mitochondria and chloroplasts. Use the tree to determine which statements regarding the origins of these organelles are true. Select all that apply. All mitochondria descended from a common ancestor. Only species in Plantae have chloroplasts. All chloroplasts descended from a common ancestor. The acquisition of mitochondria occurred after the acquisition of chloroplasts.

Polycystinea Acantharea Foraminifera Vampyrellids Rhizaria Plasmodiophora Haplosporidia Core Cercozoa Diatoms Brown algae Secondary Chrysophytes Stramenopila endosymbioses Labyrinthulids Blastocytis Dinoflagellates Apicomplexa Alvoolata Ciliates Haptophytes Cyanobacterium Centroheliozoa Glaucophytes 4 L Red algae Plantae Green algae Plastid Cryptomonads Euglenozoa Heterolobosea Jakobids Preaxostyla Excavata Fornicata Parabasalia Parabasali Malawimonas Vannellids Centramoebida Myxogastrids Amoebozoa Dictyostelids Pelobiont Host Mastigamoebida Tublinea Mitochondrion Ancyromonas Apusomon ads Breviata +Subulatomonas Animals Choanoflagellates lichthyosporea Opisthokonta a-proteobacterium L Fung Chytrids O2015 Pearson Education Inc. SAR

Solution

PART A:

The statements that are both true and support the endosymbiosis theory are:

a). Mitochondrial genes are transcribed by a polymerase that is similar to bacterial polymerases ---> TRUE (as the mitochondrial genes are derived from bacteria, both have similar polymerases)

b). Organelle DNA packaging is similar to the packaging of a bacterial chromosome ----> TRUE (the DNA packing is similar in mitochondria, chloroplasts and bacteria)

c). Many mitochondrial genes are polycistronic ---> TRUE

d). Organelle DNA packaging is similar to nuclear DNA packaging ----> FALSE (DNA is packed in chromatin in nuclear DNA)

e). Mitochondria are similar in size to some existing bacteria. ----> TRUE

f). Most mitochondrial genes are transcribed unidirectionally. ----> FALSE

PART B:

a). All mitochondria descended from a common ancestor. ----> TRUE

b). Only species in Plantae have chloroplasts -----> FALSE

c). All chloroplasts descended from a common ancestor ----> TRUE

d). The acquisition of mitochondria occurred after the acquisition of chloroplasts ----> FALSE (mitochondria were acquired prior to chloroplasts)