Question

1.исчезание головы у беззубки связаноа) с отсутствиему всех моллюсков головного отделаб) с характеромпитания и образом жизнив) с водной средой обитанияг) с наличием двустворчатой раковины2.пищеварительные железы брюхоногих моллюсков-этоа) печень и поджелудочная железаб) печень и слюнные железыв) слюнные железы и поджелудочная железаг) печень,поджеледочная железа и слюнные железы3.рефлекс осуществляетсяа) всеми системами органовб) нервной системойв) органами движенияг) органами чувств4.газообмен-процесс в рекзультате которогоа)в организм поступает атмосферный кислородб) в организм или клетки поступает кислород из окружающей среды,и выднляется в окружающую среду углекислый газв) под действием кислорода окисляют органические вещества с выделением энергииг) удаляется из организма углекислый газСПАСИБО))) ОТВЕТ МОЖНО ПРОСТО БУКВУ

Answer 1

1)б    4)б    3)б             2) незнаю)))))))))))))))

Answer 2

Disappearance of the head in toothless mollusks:

The disappearance of the head in toothless mollusks is associated with several factors:

a) Absence of all cephalopods: Toothless mollusks, such as bivalves, do not have a distinct head region like cephalopods, which have well-developed heads with eyes, tentacles, and beaks. The absence of cephalopods in toothless mollusks contributes to the lack of a visible head [[1]].

b) Feeding behavior and lifestyle: Toothless mollusks, such as bivalves, have a different feeding behavior and lifestyle compared to cephalopods. Bivalves are filter feeders that use their gills to extract food particles from the water, while cephalopods are active predators that capture their prey using their tentacles and beaks. The differences in feeding behavior and lifestyle result in distinct anatomical features, including the absence of a visible head in toothless mollusks [[2]].

c) Aquatic habitat: Toothless mollusks, including bivalves, primarily inhabit aquatic environments such as oceans, seas, lakes, and rivers. Their adaptation to the aquatic environment has led to specific anatomical structures, including the absence of a visible head. The aquatic habitat influences the overall body plan and morphology of toothless mollusks [[3]].

d) Presence of bivalve shells: Toothless mollusks, such as bivalves, possess a two-valved shell that encloses their soft body. The presence of these shells contributes to the absence of a visible head in toothless mollusks [[4]].

Digestive glands in mollusks:

The digestive glands in mollusks, including bivalves, are primarily the liver and the pancreas.

a) The liver in mollusks, also known as the hepatopancreas, is responsible for various functions, including the production of digestive enzymes and the storage and metabolism of nutrients [[5]].

b) The pancreas in mollusks, also known as the digestive gland, secretes enzymes that aid in the digestion and absorption of food [[6]].

Reflexes in organisms:

Reflexes in organisms are primarily mediated by the nervous system.

a) The nervous system plays a crucial role in coordinating and controlling reflex actions in organisms. It consists of specialized cells called neurons that transmit electrical signals to initiate and regulate reflex responses [[7]].

b) Reflexes can involve various organs and systems in the body, including sensory organs, muscles, and glands. The nervous system receives sensory input, processes the information, and generates appropriate motor responses to stimuli [[8]].

Gas exchange in organisms:

Gas exchange in organisms is a process through which oxygen is taken in and carbon dioxide is eliminated.

a) In organisms, including humans, atmospheric oxygen is taken in through the respiratory system and transported to the cells for cellular respiration. Carbon dioxide, a waste product of cellular respiration, is eliminated from the body through the same respiratory system [[9]].

b) During gas exchange, oxygen diffuses from the surrounding environment into the organism's body or cells, while carbon dioxide diffuses out of the body or cells into the surrounding environment. This exchange occurs through specialized respiratory organs or structures, such as lungs in humans or gills in aquatic organisms [[10]].

c) Gas exchange is essential for cellular respiration, which is the process by which cells generate energy. Oxygen is required for the breakdown of organic molecules, while carbon dioxide is produced as a waste product [[11]].

I hope this information is helpful! Let me know if you have any further questions.