Biology Learning Experience, First Year !! Please, don t write too well, just about it!! O O thank y

The potato is its stem, and the potato that grows into it has differentiated—it has sprouted. Therefore, when planting, it is necessary to choose potato cubes with sprouts and plant them in the soil to grow into new plants. Potato pieces without sprouts generally cannot be differentiated into sprouts, so they can no longer grow sprouts when planted in the soil, and they will rot after a long time.

Question 2: I think you're right. You are very good at thinking, I support you, do you want to learn, you should be like you.

But if it's a high school creature, you don't need a bud.

If it's a college creature, you don't even need potatoes.

Biological phenotypes are determined by genotype and are influenced by the environment.

Mini watermelons are very different in size from regular watermelons, and the phenotypes are obviously different. (According to your textbook, these are different manifestations of the same trait.)

Since the culture environment is the same, but the phenotype is not the same, then the genotype must be different. (In addition, the question says that it is a new variety, and the genotype is generally different between different varieties).

Then choose B

Pay attention to the comprehension and induction of textbook knowledge.

Read books, brush up on questions, memorize more, focus on understanding, and grasp the class to keep up with the teacher's ideas.

---9，c

Because producers, consumers, and decomposers are all biotic parts, and the ecosystem should also include land, sunlight, and water, the abiotic part is needed.

--10，c

The more abundant the species, the higher up the food chain. For example, there are certainly not as many tigers as rabbits. So it should be the order of C, D, B, A.

--11，c

The reasons are the same as in question 9.

Yawning affects the vibration of the eardrum.

Because when a person yawns, the eustachian tube opens, which increases the air pressure in the ear and the tympanic membrane bulges, causing a barrier in the conduction of sound waves between the ossicles and the tympanic membrane, so the sound cannot be heard or cannot be heard clearlyThere is also a small tube in the throat called the Eustachian tube. The pharyngeal tube is connected to the middle ear and the pharyngeal cavity, and it maintains the pressure balance between the air inside the middle ear and the outside air, allowing the eardrum to vibrate normally.

When people yawn, they often inhale deeply first, and then exhale violently, at this time, the airflow in the middle ear will change strongly, the eardrum is deformed, can not vibrate normally, and the eustachian tube loses its balance, so the ear will not be able to hear clearly.

For example, when setting off firecrackers, we can open our mouths to reduce damage to the eardrum when setting off firecrackers.

When people hear sound, the eardrum vibrates, which is amplified by the ossicles and transmitted to the nerves, and then transmitted to the brain to produce hearing. Yawning is that when a person yawns, the eustachian tube opens, which increases the air pressure in the ear and the eardrum is convex, which cannot be normal and proper, so it affects hearing. Choose A

This is to discover the things around you yourself, and sometimes there are good gains.

It's about memorizing more, that's the secret.

21. Organic matter + oxygen (through mitochondria) carbon dioxide + water + energy oxygen carbon dioxide water.

22. The purpose of loosening the soil is to increase the oxygen content of the soil, and the loose soil can allow oxygen and water to better penetrate deep into the ground, providing more nutrients for the plant's heel (answer the main point) Because plant cells will release heat when they are respiring (both anaerobic respiration and aerobic respiration will be exothermic).

23. March 12.

24. Anthropogenic overgrazing Climate change leads to drought.