сутунмӯҳрадор

сутунмӯҳрадор: vertebrate

Аксарияти сутунмуҳрадорон болҳо ва пойҳои ҷуфт доранд.
Most vertebrates have pairs of wings and legs.
Ширхӯрон ба монанди дигар сутунмуҳрадорон системаи асаб доранд.
Mammals, like other vertebrates, have a nervous system.

Bonus:
бесутунмӯҳра: invertebrates
сутунмӯҳра: spine

The suffix дор is from the verb доштан, to have. It is a very common suffix. Here are a few more examples:
остиндор: with sleeves, having sleeves
болдор: winged, with wings
бачадор: having a child/children
пулдор: wealthy, having money
таҷрибадор: experienced, having experience
чахрдор: wheeled, having wheels
хордор: thorny, having thorns

ҷигар

ҷигар: liver

Ҷигар ба системаи ҳозима дохил мешавад.
The liver is included in the digestive system.
Ҷигари гӯсфанд ё говро хуб тоза карда, калон-калон мебуранд.
The liver of sheep or cow is cleaned well, and cut into big pieces.

Bonus:
In Tajik the third person plural is often used in recipes, as the second sentence shows. If you want to translate it as written it would be “They clean the liver of sheep or cow well, and cut it into big pieces.”

ҷигарӣ, ҷигарранг: liver-coloured; maroon
ҷигарбирён: fried liver

This word is also used as an affectionate term for children or other close family and loved ones, as in “ҷигари ман”, “ҷону ҷигари ман”.

калтакалос

калтакалос: lizard

Дар Тоҷикистон 33 намуди калтакалос дучор мешаванд.
In Tajikistan one can find 33 kinds of lizards.
Аз дуди офтобпараст муш ва калтакалосҳо мегурезанд.
Mice and lizards run away from the smoke of sunflowers.

Bonus:
Also called келас.

The first sentence is written in 3rd person plural, but the English translation is better in 3rd person singular.

Notice that in the second sentence the word for mice does not have the plural ending, ҳо. That is because when listing items the plural ending only has to go on the last item in the list; putting it on the other items is optional, but usually left off. It is understood from context that both words are plural.

You can read about lizards on Tajik Wikipedia: Калтакалос

косахонаи сар

косахонаи сар: skull

Косахонаи сар зиёда аз бист устухонро дар бар мегирад.
The skull consists of more than twenty bones.
Дар аксарияти хазандаҳо скелет ба қисмҳои косахонаи сар, мӯҳраҳо, пойҳои пешу қафо ва дум тақсим мешавад.
In the majority of reptiles the skeleton is divided into the sections of skull, vertebrae, front and back legs, and tail.

Bonus:
Other uses of косахона –
косахонаи чашм: eye socket
косахонаи сангпушт: tortoise shell

You can learn more body part words by reading about nature. The second sentence for today comes from an article about reptiles on an educational website – Хазандаҳо (Reptiles)

хазанда

хазанда: reptile

Дар рӯйи Замин зиёда аз 7 ҳазор намуди гуногуни хазандаҳо зиндагӣ мекунанд.
More than seven thousand various kinds reptiles live on the face of the earth.
Ғайр аз морҳо ва калтакалоси бепой (баҳтур) ҳамаи намудҳои дигари хазандаҳо дар ду паҳлуи танаашон як ҷуфтӣ пой доранд.
Besides snakes and legless lizards, all other different kinds of reptiles have a pair of feet on both sides of their body.

Bonus:
The sentences for today came from allinweb website – Синфи хазандаҳо. The article has loads of great reading about reptiles along with good pictures of reptiles including body parts and bones. There are lots of other great educational articles on that website too.

The plural of ҳазанда can be ҳазандаҳо or ҳазандагон. The suffix -он is used for animate nouns; when the noun ends with the letter “a” the ending is -гон.

Баҳтур (or боҳтур) is a kind of legless lizard that lives in Tajikistan and other parts of Central Asia. You can read about them here: Боҳтур.

нилуфар

нилуфар: water lily

Дар дунё чил намуди нилуфар мерӯяд.
Forty kinds of water lily grow in the world.
Нилуфар гулест, ки дар кӯлҳо ва дигар обҳои истода месабзад.
A water lily is a flower that grows in lakes and other still waters.

Bonus:
Some other flower names:
садбарг: rose
офтобпараст: sunflower
наргис: daffodil

Learn more flower names at Memrise – Tajik Flowers. (You have to sign in to the site, but it is free to register.)
Read about water lilies on the Tiroz website: Гули Нилуфар.

ҳуҷайра

ҳуҷайра: cell

Ба монанди дигар мавҷудоти зинда бадани одам низ аз ҳуҷайраҳо иборат аст.
Like other living creatures, the human body is also composed of cells.
Дар ҳар як организм миқдори зиёди ҳуҷайраҳо мавҷуд аст.
In every organism there is a large quantity of cells.

Bonus:
ҳуҷайраи асаб: nerve cell
ҳуҷайраи мушак: muscle cell
ҳуҷайраи хун: blood cell