Ask a few junior high school biology questions, if you don t know, don t. Thanks for that

1.The first three are the structures that all plant cells have, and the inner epidermal cells of onions do not photosynthesize, so there are no chloroplasts.

2.The answer C is correct. The order and family are the most important taxonomic units of plants, and this should be remembered.

It's supposed to be a marine animal, right? These three types of life have different ecological niches and different ecological ways.

1.d The inner skin of the onion is purple, there are no chloroplasts in it, and there are anthocyanins.

Cell membrane, cytoplasm, nucleus, cell wall, vacuole, no chloroplast!

1. Answer D is not a cellular structure.

2, C 3, choose D

To the first I would like to add.

The microstructure of living things is determined by their own needs.

Similarly to this question, the same plant cell has no chloroplasts in the roots and no cell wall in the meristem.

1 Why doesn't onion skin have chloroplasts? I forgot this specifically, but have you ever seen a green onion? Isn't that easy to understand? So the epidermis didn't seem to remember doing this many years ago.

2 Linkep's taxonomic methods and taxonomic principles are unified, that is, seven levels are used to classify organisms step by step. The seven levels from highest to lowest are boundary, phylum, class, order, family, genus, and species. A "boundary" contains multiple phyla, a "phylum" contains multiple classes, and so on, the smallest unit of classification is species.

3 Marine organisms are generally divided into three categories: plankton, swimming animals and benthic organisms according to their lifestyle. There's nothing to say about this option.

1 d The chloroplasts will photosynthesize and they will appear green.

2·d is the most basic unit. 3·b

1D Inner epidermal cells, note (the nuclear plasma wall is inevitable, the inner epidermis has only other chromosomes, think about whether it is green?) )

2. Usually see more is a kind of life, and there are generally more plants in what family. Because the family is the most important concept in taxonomy.

3 choose B, the float is floated with the help of the waves. Benthic animals are usually attached. Needless to say, swimming.

Onions grow in the soil, and there are no chloroplasts from sunlight.

Brother Yu, you can copy me when you go to school, I've finished writing it.

1. Hydra. Paramecium is a prokaryotic unicellular organism, and hydra is a multicellular invertebrate, belonging to the stinging bubble animals, and the evolutionary level is much higher.

2. Asexual reproduction by budding reproduction.

3. The left and right symmetry is higher, and it is the higher body type in the creature. By punching the main axis, only one symmetrical cavity fiber can be formed, dividing the organism into two parts that are symmetrical to each other. Radiative symmetry has no distinction between front and back, left and right, only up and down, which is a primitive form of symmetry.

If you think about it, people are scattered and laughing, and starfish are radially symmetrical.

1. It is developed from the hypocotyl of the embryo, and the hypocotyl is between the radicle and the germ, 2. The mung bean can absorb water to germinate and form mung bean sprouts, so the mung bean sprouts are mainly water, and the vegetable farmers who sell the raw bean sprouts actually earn most of the water money.

3. When the seed germinates, the organic matter content inside it will decrease, and the respiration will provide energy for the seed germination, but the variety will increase.

4. The germination rate is large enough, and an appropriate amount of seeds can be taken for the initial test of germination rate.

1.The hypocotyl part develops, which is the part between the germ and the radicle.2 The mung bean sprouts into mung bean sprouts to absorb a lot of water and earn water money.

3. Seed germination. When the organic matter inside it is reduced, it provides energy for seed germination.4 The germination rate is large enough, and an appropriate amount of seeds is taken for experimental measurement of germination rate.

(1) From the question, it can be seen that when 4>1, that is, the body is not hydrated, the secretion of antidiuretic hormone increases to promote the renal tubules, and the reabsorption of water by the collecting ducts is 3 increases, and 2 is the secretion of digestive juices, which is not affected.

2) Intravenous injection of amino acids will lead to an increase in the osmotic pressure of extracellular fluid, and the same will increase the amount of antidiuretic hormone, thereby promoting the reabsorption of the renal tubular collecting ducts.

In addition: (1) the serial number under the condition 1 is the water in the food 2 is the water in the digestive juice 3 is the water reabsorbed 4 is the water lost (including sweat and the evaporation of **).

2) Under the conditions, the serial number 1 is the small intestinal epithelial cells (absorption), 2 is the gastric glands, intestinal gland cells, etc. (secretion), 3 is the renal tubular collecting duct cells (reabsorption), and 4 is the sweat gland sebaceous gland cells (secretion).

: digestion and absorption; secreted into the digestive tract in the form of digestive juices; reabsorption; Sweating.

1) When perspiration is greater than the absorption of digestive tract, the secretion of digestive juice remains unchanged, and the reabsorption of water by renal tubules and collecting ducts becomes larger.

2) When amino acids are instilled intravenously, it is related to the vital activities of the digestive tract and whether or not to eat, so it is not affected; enhanced reabsorption; **The excretion is basically unchanged.

1 is the water in the food, 2 is the digestive juice, if 4 is greater than 1, then the osmotic pressure in the body increases, and the reabsorption of 3 will be enhanced, but 2 will not change. The second question is that because it is injected intravenously, it does not pass through 1 small intestinal epithelial cell.

Amino acids do not go through 1, so their activity is not enhanced, 2 are endocrine cells, 3 are renal tubular cells, and 4 are epithelial cells.