Class Mammals or Animals
OPTION 1
A1. Maintaining a constant body temperature is characteristic of
2) hedgehog
4) turtles
A2. The beaver has a characteristic body covering
1) hair
2) feather
3) chitinous
4) scaly
AZ. The horse's hoof is a modified area
1) skin
2) foot bones
3) phalanges of the finger
4) shin bones
A4. Complication nervous system mammals is expressed in an increase
1) cerebral cortex
2) medulla oblongata
3) spinal cord
4) nerve nodes
A5. Unlike birds in digestive system mammals available
1) esophagus
3) set of teeth
4) pancreas
A6. The four-chambered heart in the circulatory system has
1) lizard
2) dog
3) frog
B1.
A. Among mammals, there is a subclass of Oviparous animals, which reproduce by eggs (platypus and echidna).
B. Representatives of different orders of mammals differ in the structure of the dental apparatus.
1) Only A is correct
2) Only B is correct
3) Both judgments are correct
4) Both judgments are incorrect
B2. Choose three true statements. Representatives of the order Pinnipeds mammals are
1) seal
2) dolphin
4) walrus
5) fur seal
6) shark
BZ.
FEATURE OF LIFE ACTIVITIES
A. The act of double breathing (gas exchange during inhalation and exhalation)
B. Feeding the young with milk
D. Carrying a baby in the body of a female
ANIMAL CLASS
1) Mammals
B4.
1) Amphibians
4) Reptiles
Answer: 3, 1, 4, 2.
B1. Assignment to work with picture 7.
A, Which animal organ system is shown in Figure 7?
1) digestive
2) circulatory
3) respiratory
4) nervous
B. What function is provided by the organs indicated in Figure 7 by number 1?
1) digestion
2) reproduction by eggs
3) egg maturation
4) act of double breathing
IN. The organs indicated in Figure 7 by number 2 are involved in
1) heartbeat
3) movement of food
4) urine formation
OPTION 2
A1. Feeds cubs with milk
1) penguin
2) crocodile
4) fox
A2. Sebaceous and sweat glands are located in the skin
1) proteins
2) lizards
3) penguin
4) partridges
A3. Unlike reptiles, the skeleton of mammals changes significantly in structure
1) skulls
2) shin bones
3) upper limb belts
4) caudal spine
A4. Unlike reptiles, the hearing organ of mammals includes
1) middle ear
2) eardrum
3) auricle
4) cochlea of the inner ear
A5. Organ of gas exchange in respiratory system dogs serves
1) alveolar lungs
4) larynx
A6. During the development of an embryo in animals, the placenta, or baby's place, is formed in
1) uterus
2) ovary
4) testis
B1. Are the following statements true?
A. Representatives of the order Cetaceans - dolphins and whales - breathe with gills.
B. In marsupial mammals (kangaroos, opossums), the young are born underdeveloped, and their further development occurs in the mother’s pouch.
1) Only A is correct
2) Only B is correct
3) Both judgments are correct
4) Both judgments are incorrect
B2. Choose three true statements. Representatives of the rodent order are
2) beaver
3) jerboa
4) bat
6) rat
BZ. Establish a correspondence between the characteristic of life activity and the class of animals for which it is characteristic.
FEATURE OF LIFE ACTIVITIES
A, Maintaining a constant body temperature
B. Reproduction by eggs or ovoviviparity
B. Unsteady body temperature
D. Most representatives are characterized by viviparity
ANIMAL CLASS
1) Reptiles
Write down the corresponding numbers in the table.
B4. Establish the sequence of occurrence during the evolution of classes of chordates.
1) Reptiles
3) Mammals
4) Amphibians
Answer: 2, 4, 1, 3.
B1. Assignment to work with picture 8.
A. Which animal organ system is shown in Figure 8?
1) digestion
2) blood circulation
3) breathing
4) nervous
B. The systemic circulation originates in
1) left ventricle
2) right ventricle
3) right atrium
4) left atrium
IN. Through the vessels of the small circle, blood enters the
1) light
3) stomach
4) skeletal muscles
The hooves are located on the third phalanx of the third toe of odd-toed ungulates, including horses. The hoof is a hard skin tip that protects the end of the toe from damage. The hoof is an area of skin, the epidermis of which in certain places produces horny layers of varying structure and consistency. Therefore, according to the location and nature of the stratum corneum produced, the following 4 parts are distinguished on the hoof: border, corolla, wall and sole (Fig. 1).
Rice. 1. Structure of a horse’s hoof: (Fig. on the left - outside view): 1 – toe part; 2 – lateral side wall; 3 – heel part; 4 – corolla area; (Fig. on the right - view: sagittal median section): 5 - three layers of border; 5 – glaze; 6–3 layers of corolla; 6 – tubular horn; 7 – coffin bone; 8 – dermis of the hoof wall; 8 – white leaf horn; 9 – white line; 10 – dermis of the sole; 11 – crumb horn; 12 – dermis of the crumb; 13 – elastic crumb cushion
The hoof border is a narrow strip at the border between the hairy skin and the underlying hoof crown; connects the hairy skin with the horny capsule and softens the pressure of the pointed tip of the horny capsule. The hoof corolla is located below the border, covering the tendon of the finger in front, and the spinal cartilage on the side. The hoof wall, the most massive part of the hoof, covers the coffin bone and spinal cartilage. There are 3 horny layers on it - glaze, tubular horn, leaf horn. The final section of the latter forms a white line, which is a guideline when shoeing horses (it is insensitive, so nails are driven along it). The sole of the hoof is a concave plate with a cone-shaped cutout for the digital pulp, located on the lower surface of the hoof. The thickness of the sole horn is not constant, as it wears off when walking.
Rice. 2. Horse hoof (bottom view): a – horny wall; b – sole and frog; 1 – collar part; 2 – heel angle; 3 – side part; 4 – toe part; 5 – arrow; 6 – sole; 7 – white line
Saddle horses have denser hooves, with an elastic horn, while heavy draft horses have loose hooves, with a soft hoof horn. Disadvantages and defects of the hooves are caused by their irregular shape, poor-quality horn, incorrect positioning of the legs, and poor hoof care. Many of them lead to lameness. Crumbs. These are the supporting areas of the limbs. They are rich in nerve endings, due to which they act as an organ of touch. Horses have a toe ball in the shape of a wedge split by a groove. It consists of a pillow, an arrow and cartilage (Fig. 2) and acts as a spring, softening shocks when leaning on the ground.
Basic level
For each task, choose one correct answer from the four proposed.
A1. Maintaining a constant body temperature is characteristic of
- turtles
A2. The beaver has a characteristic body covering
- hair
- feather
- chitinous
- scaly
AZ. The horse's hoof is a modified area
- foot bones
- finger phalanges
- shin bones
A4. The increasing complexity of the mammalian nervous system is reflected in an increase
- cerebral cortex
- medulla oblongata
- spinal cord
- nerve ganglia
A5. Unlike birds, the digestive system of mammals has
- esophagus
- liver
- set of teeth
- pancreas
A6. The four-chambered heart in the circulatory system has
- lizard
- dog
- frog
- perch
- - - Answers - - -
A1-2; A2-1; A3-1; A4-1; A5-3; A6-2.
Increased difficulty level
B1. Are the following statements true?
A. Among mammals, there is a subclass of Oviparous animals, which reproduce by eggs (platypus and echidna).
B. Representatives of different orders of mammals differ in the structure of the dental apparatus.
- Only A is correct
- Only B is correct
- Both judgments are correct
- Both judgments are wrong
B2. Choose three true statements. Representatives of the order Pinnipeds mammals are
- seal
- dolphin
- fur seal
- shark
BZ. Establish a correspondence between the characteristic of life activity and the class of animals for which it is characteristic.
Features of life
A. The act of double breathing (gas exchange during inhalation and exhalation)
B. Feeding the young with milk
B. Ligaments located in the trachea are involved in the formation of the voice
D. Carrying a baby in the body of a female
Animal class
- Mammals
- Birds
Write down the corresponding numbers in the table.
B4. Establish the sequence of occurrence during the evolution of classes of chordates.
- Amphibians
- Birds
- Reptiles
- - - Answers - - -
B1-3; B2-145; B3-2121; B4-3142.
The coffin bone in a horse is a kind of shock absorber that prevents injury when moving. Therefore, it is the main functional component of the animal’s body, affecting its health and performance. The structure of the horse's hoof allows the horse to effectively distribute weight, providing better traction with the ground.
Ground grip
What is a hoof
The hoof is a keratinized capsule that protects the tip of the horse's toe from damage and is similar to the claws of wild animals and human nails. Horse hooves require careful care. Incorrect positioning or incorrect shape of the legs from birth leads to serious damage, for example, illness.
The structure of the horse's hoof is special, because the thickness of the stratum corneum of the hoof varies in individual areas. It contains:
- sock;
- heel;
- sole;
- crown ring;
- arrow;
- corner;
- side wall;
- heel wall;
- toe wall.
It is easy to find the coronoid ring in the structure of a horse's hoof. It is located at the hair growth line. The hoof bone and soft cartilage are covered by a horny wall consisting of:
- glaze;
- tubular horn;
- leaf horn.
Hoof parts The sole of the horse's hoof differs from other parts in that it does not have a stratum corneum. It consists of a horny arrow and a white line. The horny arrow is needed to prevent slipping. It is located like a wedge between the legs of the sole. The white line is made of non-sensitive fabrics and is therefore suitable for driving when forging nails. If you do not monitor the condition of the hooves, it can develop, which will lead to a serious limb problem.
A horse's front and rear hooves differ in shape and size. The hind ones are smaller than the front ones, the sole is concave inward. The front hooves have a larger frog and a low heel bone.
Horses have their hooves trimmed periodically as the hoof horn grows. Hoof trimming corrects leg position and distributes weight correctly. The hooves are also trimmed before shoeing to ensure a good fit of the horseshoe to the sole. Occasionally, hoof trimming is done for medical reasons and for some horseshoe diseases.
Hoof after cleaning Horses of riding breeds have dense hooves and elastic horns, while heavy horses have loose hoofs and soft horns.
The difference is also visible in size - the draft horse has a larger hoof. The shape of the hoof is also different: the heavy hoof has flat walls and a low heel, while the horse hoof has round walls and a high heel.
At the hooves various types colors: dark, light, striped and mixed. But the dark ones are considered the strongest hooves.
A simple horse's hoof serves many functions, which is why good hoof care is so important.
The horse's leg is covered with a strong horn shoe - a hoof. This important organ provides the horse with stability, fast running and protection from enemies.
Eohippus
The lower part of a horse's leg is its only toe, and the hoof is a modified, greatly overgrown nail.
Have horses always had such legs and such hooves? Russian scientist V.O. Kovalevsky (1873) proved that the ancient ancestors of horses had a five-toed limb.
About 50 million years ago, the middle zone of the Northern Hemisphere was covered with lush tropical forests, in which lived Eohippus, the ancestor of modern horses. 
Orohippus
It was the size of a fox and had five toes on its feet, of which only 3-4 touched the ground. Eohippus hid in the forest thickets and ate vegetation.
The climate on earth changed, and in connection with it, the living conditions of plants and animals. Steppes with grassy vegetation formed. Living in open places, the horse's ancestors learned to run quickly to avoid falling into the clutches of predators. 
Mesohippus
The side fingers turned out to be redundant. The middle toes served as support for the body.
The four- and three-toed ancestors of horses that lived in North America: orohippus, 38 centimeters tall, and mesohippus, longer-legged, already about 60 centimeters tall. At that time, the American and Asian continents were connected to each other. At the site of the Bering Strait, animals easily crossed from the western to the eastern hemisphere. 
Merikhippus
Primitive horses in America died out about 30 million years ago, and their descendants moved to Asia. Merikhippus is already very similar to a horse, but has three more toes on its feet.
Modern horses do not have three toes. But, comparing the skeletons of a horse and its ancestors, you can see two thin bones adjacent to the metatarsus. This is nothing more than the remains of an ancient horse “paw”.
