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Anonymous users2024-02-07Lying on two pairs of homologous chromosomes follows the law of free combination, and two pairs of genes on the same chromosome follow the law of gene linkage interchange.
In 1909, the American geneticist Morgan and his students used the hybrid experiments conducted by Drosophila on the basis of Mendel's law to reveal the inheritance law of more than two pairs of alleles located in different locies on homologous chromosomes, that is, the famous linkage and exchange law. Its basic content is that in the process of germ cell formation, genes located on the same chromosome are linked together and passed on as a unit, which is called the linkage law.
During germ cell formation, there can be an exchange between different pairs of alleles on a pair of homologous chromosomes, known as the exchange law or exchange law.
Isn't it the same on two pairs of homologous chromosomes as on non-homologous chromosomes? Please read the topic clearly.
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Anonymous users2024-02-06The number of homologous chromosomes should be two. So the meaning of the first sentence is that the four chromosomes are divided into two types, the first one has the A gene, the second has the B gene, and the second sentence is that the two chromosomes are one, and one chromosome has two genes, A and B.
For the topic, there are two expressions of the same question. All indicate that they are not chained. The two pairs of homologous chromosomes in question 1 have the same meaning as those in question 2 on non-homologous chromosomes, because the second pair of chromosomes becomes non-homologous chromosomes relative to the first pair of chromosomes.
For example, chromosome 1 has a gene and chromosome 2 has a gene b, and chromosome 1 and 2 are called non-homologous chromosomes, which are also called two pairs of homologous chromosomes.
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Anonymous users2024-02-05The first is two pairs, which means that there are 4 chromosomes, and two pairs are paired, respectively, indicating that they are on the homologous chromosomes and non-sister chromatids (I don't know how to check), and the second one is only said to be homologous staining, which may be a pair, two pairs.
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Anonymous users2024-02-04One is equitable, symmetrical.
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Anonymous users2024-02-03Frog mature red blood cells do not have a nucleus.
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Anonymous users2024-02-021) Follow. 2) Not following.
4) 1. The two pairs of alleles controlling the above traits are located on 1 pair of homologous chromosomes.
Design experiments: F1 generation and short-rod susceptibility were crossed, and the experiment was repeated many times to count the phenotype and proportion of F2.
Expected experimental results: Tested offspring with high pole resistance: tall pole susceptibility: short pole resistance: short pole susceptibility = 4:1:1:4.
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Anonymous users2024-02-011) Follow (2) Don't follow.
1. Located on a pair of homologous chromosomes.
The experimental design, using the method of crossing, that is, the hybridization of the child generation with homozygous recessive hyrificiality, can best reflect the genetic composition of the own band.
3) Cross-swaps.
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Anonymous users2024-01-31This statement is definitely wrong.
Since it is called a "migratory bird nature reserve", the main purpose must be "to protect migratory birds", not to "protect tidal flats or marshes".
Migratory bird nature reserves must be breeding grounds, or wintering grounds, or stopover places on their migratory journeys. Such a place may be a tidal flat or swamp, or a mountain, a forest, a lake, a river, etc., or a grassland.
There are many species of migratory birds, each with its own habits and the environment in which it lives, and it does not necessarily have to be a tidal flat or swamp. Of course, the Migratory Bird Nature Reserve should protect the environment, but its purpose is to better adapt to the survival of migratory birds, and it is for the purpose of protecting migratory birds to protect the environment.
If it is purely for the protection of tidal flats or swamps, it is usually not called "migratory bird reserve", but "so-and-so wetland reserve", and its purpose may be to protect single or multiple biological resources, among which there may be migratory birds, or other organisms, such as certain species of plants. It may even be broader "biodiversity" or the need to maintain ecological balance.
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Anonymous users2024-01-30Nucleomimetic, cytoplasmic inheritance.
Sodium citrate is used for blood clotting that is not used; The function of calcium chloride is to protect the pigment from being destroyed in the test of extracting pigment; 70% and 80% alcohol is not known where to be used, and 95% cooled alcohol is used in DNA extraction experiments.
In the first chapter of the third volume of high school biology, there is an interchange diagram of plasma, lymph, and interstitial fluid, as long as the circulation of interstitial fluid and other body fluids is disrupted, it will cause tissue edema, especially capillary rupture.
The promoter and terminator are not known what they are, the start codon and stop codon are the markers of the beginning and end of the RNA translation process.
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Anonymous users2024-01-29Variants that can be inherited Genetic mutations Genetic recombination.
Sodium citrate coagulation Calcium chloride changes the permeability of the membrane Genetic engineering uses different concentrations of alcohol rinsing during transformation.
Tissue edema, malnutrition, allergic reactions, etc.
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Anonymous users2024-01-28Heritable variations in prokaryotic cells generally have only DNA mutations.
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Anonymous users2024-01-27．（1）aabb×aabb aabb×aabb
a Progeny plant pink:red:white = 6:3:7
c Progeny plant pink:red:white = 2:1:1
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Anonymous users2024-01-26When only aerobic respiration is performed, device A shifts to the left and device B does not move. Inside the first device is a sodium hydroxide solution (sodium hydroxide absorbs carbon dioxide, and the volume of gas in the bottle decreases, so it shifts to the left), and the distance traveled indicates the amount of oxygen consumed by the seed's respiration.
B does not move because the oxygen consumed is equal to the volume of carbon dioxide gas produced by respiration (both with glucose as the respiration substrate).
If anaerobic respiration is performed, A does not move, and B moves to the right (anaerobic respiration does not consume oxygen, produces carbon dioxide, and is absorbed by sodium hydroxide in device A, so it does not move.) The volume of gas in B increases, so it shifts to the right).
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Anonymous users2024-01-25Hello lz. C is wrong of course.
A dominant disorder means that both x(h)x(h) and x(h)x(h) can cause disease.
Suppose a group of women has n1 x(h)x(h), n2 x(h)x(h), and n3 normal people.
Then the gene frequency of x(h) = (2*n1+n2) [2*(n1+n2+n3)].
And the incidence = (n1+n2) (n1+n2+n3).
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Anonymous users2024-01-24Cells are divided into two categories: eukaryotic cells and prokaryotic cells, according to the nucleus within the cell (whether there is a nuclear membrane or not).
Prokaryotes: (1) Types of prokaryotes: (bacteria, cyanobacteria, mycoplasma, chlamydia, rickettsia) and so on.
2) Cyanobacteria have (light and pigment) and contain (chlorophyll) and (phycocyanin) in cells, and are autotrophic organisms that can carry out (photosynthesis).
Fungi belong to (eukaryotic) organisms and include (fungi, molds, and yeasts).
Volume: Eukaryotic cells are comparatively smaller, and prokaryotic cells are comparatively larger.
Cell wall components: eukaryotic cells, fungi are chitin, plant cells are cellulose and pectin; Prokaryotic cells: Bacteria are peptidoglycan.
Cytoplasm: Eukaryotic cells contain a variety of organelles, and prokaryotic cells have only ribosomes.
Nucleus: Eukaryotic cells have a nuclear membrane and have chromosomes. Prokaryotic cells do not have a nuclear membrane, no chromosomes, and have nucleoides, chromatin.
First, the dominant recessive nature of albinism and sickle anemia was determined, and according to the left half of Figure 1, it can be concluded that anemia is a recessive genetic disease, which is bb; Then look at Figure 2, because if it is normal, it can be cut, and if it is not normal, it can't, so B is normal, C is albino, and both are homozygous, only A is heterozygous (because A can cut out three pieces: DNA is a double helix structure, only one of A can be cut, B can be cut all of them, cut into two short and two long, C is not cut) Because albinism is a recessive genetic disease, it is AA, so it can be known that B is AA and C is AA >>>More
No, you can look at the concept of chromosomal variation. As for the ...... translocationTranslocation is the transfer of a segment of one chromosome to another non-homologous chromosome, causing a variation. ......This is the concept, note that there are non-homologous chromosomes, and cross-swapping is between homologous chromosomes.
Dizzy, buy a reference book.
p17, the enzyme that catalyzes the hydrolysis of lipase.
Lipase"It is an enzyme, and the enzyme is a protein, so it is natural to use protease. >>>More
In fact, you don't have to be so nervous, you may just put too much pressure on yourself, relax, and the workbook or something wrong is a good thing, learn more lessons, don't miss it again, and the review before the exam is very important, I usually look at the notes, and then see that I am not very familiar with the will be memorized, and then 5.3 wrong questions to see more, but there is no need to do 5.3 in the second year of high school, you can try my method, maybe it will get better.