Help with some questions about the second year of junior high biology competition

adbbb Wrong Right Right Wrong Hyposis Thyroid gland.

BCBBB Wrong Wrong Right Wrong Cretinism Thyroid gland.

adacb wrong right wrong right wrong cretinism hypothalamus.

1a2d3b4b5b6 is wrong and 7 is true. 8, 9, 10 are all right. 12.Cretinism 14Thyroid gland. 11,12 is no problem.

No, variations are divided into heritable variations and non-heritable variations. If these variations are caused by environmental factors, there is no change in genetic material and therefore cannot be passed on to future generations, and they are non-inherited.

For example, if the same wheat seeds are sown in different water and fertilizer conditions, the variation of the wheat plants grown in terms of height and fullness of seeds is not heritable.

Some variants are caused by changes in genetic material and can therefore be passed on to future generations.

For example, albinism in humans is caused by changes in genes (i.e., genetic material).

Do you understand?? *Hey, the code word is so hard!

It's not all high school biology book 2 that tells about the ** of mutations.

Heritable and non-heritable variation.

Variations that generally occur on germ cell nucleic acids are the former.

Mutations that occur in somatic cells are the latter.

There are two kinds of variations: one is the change of genetic material, which is caused by the change of genes, i.e., DNA, for example, mutations can be inherited; The other is caused by the environment and cannot be inherited.

Mutation** is genetic mutation, genetic recombination and chromosomal variation, which is a change in genetic material!

1b (algae live in water) 2d3c

4b5a6c7c

8c9b (grass is 100, then insect is 20, and so on, it should be b) 10d11abc

12ACD (applied to practical production is called technology, and item B is the natural physiological response of people) 13ABCD

14ac15ab (The fact that the birth rate of a person is greater than the death rate is the cause of population growth, not the cause of faster population growth).

I asked. The high school attached to Peking University.

16 Writing A20 Writing Environment.

Other. Forget it.

And also. I'll ask you in the next chapter.

If you lack thyroid hormone at an early age, you will develop (cretinism).

Thyroid-stimulating hormone is secreted by the thyroid gland.

The final metabolites of different nutrients are different, and the final metabolites of the same nutrient are also related to the genetic properties and environmental factors of the organism. However, glucose and fatty acids are certainly not final metabolites, and urea and uric acid are in some organisms.

In general, sugars and fatty acids can be metabolized into CO2 and water under aerobic conditions, and the metabolic end products of nitrogen-containing substances are ammonia, urea, uric acid, etc.

In the absence of oxygen, organisms can convert sugars and fatty acids into alcohol, glycerin, lactic acid and other organic acids, and some microorganisms even convert them into methane, hydrogen, etc.

Primary metabolites refer to substances that are necessary for the growth and reproduction of microorganisms through metabolic activities, such as amino acids, nucleotides, polysaccharides, lipids, vitamins, etc. Through primary metabolism, nutrients can be converted into structural substances, physiologically active substances or provide energy for growth, so primary metabolites are usually essential substances for the survival of the body, as long as there is an obstacle in a certain link in the synthesis process of these substances, it will cause growth to stop, and it will lead to mutation or death in the body, which is a basic type of metabolism.

Secondary metabolites refer to substances that are produced by microorganisms at a certain stage of growth with complex chemical structures, have no obvious physiological functions for the organism, or are not necessary for the growth and reproduction of microorganisms, such as antibiotics, toxins, hormones, pigments, etc. Different species of microorganisms produce different secondary metabolites, which may accumulate inside the cell or excrete into the environment.

Environmentally-induced variation is not heritable, rightly so, as long as the structure of the genetic material has not changed, all variations are not heritable. There are two types of variations, those that are heritable and those that are not. Variations produced by environmental factors do not alter the structure of the microorganism's genetic material.

Modern genetics has shown that non-heritable variations have nothing to do with evolution, but rather heritable variations, which are due to changes in genetic material in the form of mutations and recombinations.

b.The result of the generation-by-generation selection of antibiotics to pathogens, antibiotics can not cause resistance, the emergence of resistance is due to the mutation of microbial genes, which has nothing to do with antibiotics, mutations are generally carried out spontaneously, mutagens can increase the frequency of mutations, antibiotics only play a selective role, under the selection of antibiotics, only drug-resistant microorganisms can survive, so mutant strains continue to accumulate, more and more, macroscopically manifested as increased drug resistance.

Geography of the Yangtze River: The longest river in Asia, with a total length of 6,397 kilometers. It originates from the Tanggula Mountains on the Qinghai-Tibet Plateau and empties into the East China Sea.

The Yellow River is the second longest river in China, the fifth longest river in the world, and the river with the highest sediment content in the world. It originates in Bayan Kala Mountain and flows into the Bohai Sea.

Pearl River: It is the third longest river in China and the second largest river in China by annual flow. It originates from the Yunnan-Guizhou Plateau and flows into the South China Sea.

The Indus River: Originates in the Himalayas and empties into the Arabian Sea.

The Ganges: Originates in the Himalayas and empties into the Bay of Bengal.

The Ob River: originates in the Altai Mountains and empties into the Arctic Ocean.

The Yenisei River: Originates in the Eastern Sayan Mountains and empties into the Arctic Ocean.

The Lena River: It originates at an altitude of 1,640 meters in the Baikal Mountains, south of the Central Siberian Plateau, and empties into the Arctic Ocean.

Volga: Originating in the Vartai hills in the territory of Ostashkov County, Tver Region, and emptiring into the Caspian Sea, it is the longest inland river in the world and has a high shipping value.

That's probably it, the Yangtze River and the Yellow River are the focus, memorize it well

China's neighbors: remember this mantra: it is bordered by North Korea and North Mongolia to the east, Russia to the northeast and northwest, Kazakhstan (Kazakhstan), Kyrgyzstan (Kyrgyzstan), Tajikistan (Tajikistan), Afghanistan (Afghanistan), Pakistan (Pakistan), southwest India, Nepal (Nepal) and Bhutan, and Myanmar, Laos (Laos) and Vietnam (Vietnam) to the south

And China across the sea:

South Korea, Japan, Philippines, Malaysia, Indonesia, Brunei.

Bleeding gums should be treated with vitamin C

Eat more foods that contain more vitamin A at night.

Lack of vitamin D in food, vitamin D deficiency can lead to rickets.

I won't say much about the rest, it should be in the book. Hope these are helpful to you o(o

That geography is readily available on the Internet. You should have sent review materials and flip books to find, rote memorization is not enough. If you want to combine vitamins in books, I remember that the first volume of junior high school or the second volume of the book wrote what vitamins were lacking and what diseases were changed.

I'll take the exam soon, so if you're interested, I'll 237516441 discuss it together.

Biology: Eat more sugars and proteins when you are nervous Bleeding gums eat VC Eat VC Eat VA Babies will be obese, malnourished, anemia, rickets Geography is not easy to find, give a point.

Babies need protein for growth, and too little protein intake can affect baby growth.

1.Lactic acid bacteria are anaerobic bacteria that break down organic matter into lactic acid and carbon dioxide in the absence of oxygen or oxygen. Capping and sealing with water are used to isolate contact with oxygen in the air and contamination by other strains, which can affect the fermentation effect.

2.In summer, the temperature is high, and the growth and reproduction of bacteria and fungi accelerates.

3.Washed and dried clothes are dry and devoid of organic matter, and bacteria and fungi do not multiply easily. Dirty clothes, dirty boots, contain moisture and leave organic matter behind, therefore, bacteria and fungi are prone to multiply.

1.Lactic acid bacteria are anaerobic bacteria that only function in the absence of oxygen.

2.Bacteria are active when the temperature is high.

3.Unwashed clothes and shoes have more bacteria on them, which is not hygienic enough, so they will grow mold.

1. It belongs to white blood cells.

2. The cardiovascular system is composed of the heart, blood vessels and blood. The heart and blood vessels form a closed system of tubes in which blood circulates and flows.

The lymphatic system collapses and consists of lymphatic vessels, lymphatic organs, and lymph. Lymphatic organs include the spleen and lymph nodes. Lymph refers to the fluid that flows through the lymphatic vessels, which is formed by the penetration of interstitial fluid through the capillary lymphatic vessels. Tuan Lu.

The lymph flows through the lymphatic system and finally flows through the total lymphatic vessels into the left and right subclavian veins.

Lymphatic circulation is a supplement to blood circulation.

1 white blood cell.

2. Cardiovascular system: heart, arteries (aorta, truncus arteriosus, arterioles), veins (anterior portal vein), capillaries, etc.

Lymphatic trunks, lymphatic vessels, and capillary lymphatic vessels (from coarse to fine) are examined for fissures.

d Because ginkgo biloba is gymnosperm.

Gymnosperms do not require water for the reproductive process.

d Because ginkgo biloba is gymnosperm.