Two error-prone knowledge points (1) 1 in senior high school biology are called recessive traits.
Recessive trait is the trait of a homozygous parent, which has a pair of relative traits that are not revealed in the first generation, rather than the traits that are not revealed in the general sense.
In the genetic experiment of a pair of relative traits, parents have only one pair of relative traits.
No? Parents only have a pair of relative traits? , but a researcher? Focus only on a pair of relative traits? There is no creature with only a pair of relative characters.
3. There is no homozygote in the inbred offspring of heterozygote.
Theoretically, half of the inbreeding offspring of heterozygotes with a pair of alleles are homozygotes.
4 Homozygous hybrid offspring must be homozygous.
The same homozygous hybrid offspring is homozygous; Different homozygous hybrids are heterozygotes.
Gene 5 is equally likely to appear in daughter cells.
Genes include nuclear genes and cytoplasmic genes. For sexually reproducing organisms, nuclear genes have equal opportunities to appear in daughter cells; The chances of cytoplasmic genes appearing in daughter cells are unequal.
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The phenomenon of gene separation and the law of gene free combination have the same cytological basis.
Their cytological basis is different; The former is the separation of homologous chromosomes, while the latter is the free combination of non-homologous chromosomes.
Seven genotypes are the same, and the phenotype must be the same.
Genotypes are the same, and phenotypes may be different. The reason is different environmental conditions.
The phenotype is the same, and the genotype must be the same.
The phenotype is the same, but the genotype can be different. For example, when fully dominant, individuals with the same dominant gene.
Different genotypes must have different phenotypes.
Different genotypes may have the same phenotype. For example, when fully dominant, individuals with the same dominant gene. Different genotypes can have different phenotypes. For example, when fully dominant, recessive homozygotes and individuals with dominant genes.
The genotype of 10 must be different with different phenotypes.
Genotypes may be the same, but phenotypes are different, because environmental conditions are different.
Two error-prone knowledge points in senior high school biology (2) 1 All living things can undergo meiosis.
Only organisms that can reproduce sexually can undergo meiosis.
2 cells divide twice in succession, and there must be meiosis.
If the chromosome is copied only once and the cell divides twice in succession, then it must be meiosis;
If the cell divides twice in a row and the chromosome replicates twice, then only mitosis can occur.
Somatic cells can undergo meiosis.
Somatic cells cannot undergo meiosis, but mature spermatogonia and oogonia can undergo meiosis.
Germ cells can undergo meiosis.
Germ cells cannot undergo meiosis.
The daughter cells produced by meiosis are mature germ cells.
The daughter cells produced by meiosis need to further develop into germ cells.
During meiosis of 6 cells, chromosomes can appear in pairs.
During cell meiosis, only homologous chromosomes can be paired.
Only cells that undergo meiosis have homologous chromosomes.
Organisms capable of meiosis also have homologous chromosomes in their somatic cells.
There are no homologous chromosomes in somatic cells, but there are homologous chromosomes in germ cells.
For multicellular organisms, haploid somatic cells with only one genome have no homologous chromosomes, and all somatic cells have homologous chromosomes. There are no homologous chromosomes in the germ cells of diploid organisms; Homologous chromosomes in germ cells of polyploid organisms.
In the process of meiosis, homologous chromosomes must be separated from each other and enter different gametes.
It is true in general, but it is not true if the chromosome number variation occurs. Such as 2 1 trisomy syndrome.
10 meiosis, centromere division, homologous staining.
Chromaticity mismatch
After the second meiosis, there are no homologous chromosomes in the cell, so it is impossible to discuss the problem of pairing and unpaired.
The two error-prone knowledge points (3) 1 alleles in senior high school biology are located on homologous chromosomes, so when gametes are produced, they must be separated from each other and enter different gametes respectively.
The above statement is true under normal circumstances, but it is not true if the chromosome number variation occurs.
Both genes follow the law of separation and free combination.
Genes include nuclear genes and cytoplasmic genes; Nuclear genes are on chromosome DNA, including alleles and non-alleles; Non-alleles are located on a pair of homologous chromosomes or non-homologous chromosomes; Alleles all follow segregation phenomenon; Non-alleles located on non-homologous chromosomes all follow the law of free combination; Non-alleles located on homologous chromosomes do not follow the law of free combination; Cytoplasmic genes do not follow the laws of segregation and free combination.
3 in any DNA molecular chain, there are A=T and g = C.
In any chain of DNA molecules, generally speaking, A=T and G=C are very accidental.
In DNA molecules, each base molecule is connected with a phosphoric acid and a deoxyribose.
In DNA molecules, each base molecule is directly connected to deoxyribose.
In five DNA molecules, each phosphate molecule is directly connected to two deoxyriboses.
In DNA molecules, most phosphate molecules are directly connected to two deoxyriboses; There are two phosphate molecules (located at the 5' end) connected to only one deoxyribose.
Gene 6 is the basic unit of DNA, which is all located in the nucleus and is an arbitrary fragment of DNA.
Gene is a functional unit of genetic material DNA, which is mainly located in the nucleus and is a DNA fragment with genetic effect.
Replication of DNA molecules must take place in the nucleus, while transcription can only take place in the cytoplasm.
The replication and transcription of DNA molecules mainly occur in the nucleus; DNA replication and transcription can also occur in mitochondria and chloroplasts of cytoplasm. Both DNA replication and transcription in prokaryotic cells occur in cytoplasm.
8 DNA can directly control the biosynthesis of protein.
DNA can not directly control the biosynthesis of protein, but indirectly control the biosynthesis of protein through mRNA.
The replication and transcription of DNA take a DNA as a template, while the translation takes mRNA as a template.
DNA replication takes double-stranded DNA as template; Transcription takes a DNA strand as a template.
10DNA, mRNA, tRNA and rRNA all contain codons encoding amino acids.