Genetica

The given organism with the genotype RrTt can produce gametes of type Rt. This is because during gamete formation, the chromosomes segregate independently, resulting in different combinations of alleles in the gametes. In this case, the R and r alleles can segregate independently, as can the T and t alleles. Therefore, one of the possible combinations is Rt, where the R allele is paired with the t allele.

The correct answer is AB, Ab, aB, ab. This is because the genotypes of all the gametes formed by an organism with the genotype AaBb will contain either an A or aB allele, and either an a or a b allele. Therefore, the possible combinations are AB, Ab, aB, and ab.

The correct answer is "este pur din punct de vedere genetic". This means that the individual is homozygous for the trait, meaning they have two identical alleles for that particular gene. As a result, they will pass on the same allele to their offspring, making them genetically pure for that trait.

The correct answer is "este dublu homozigot." This means that the organism has two identical alleles for a particular trait. In this case, the organism has two copies of the allele A and two copies of the allele B. This ensures that the organism will pass on the same alleles for that trait to its offspring.

Genotip înseamnă totalitatea genelor (factorilor ereditari). Genotipul reprezintă ansamblul de gene pe care un organism le deține în cromozomi și care determină caracteristicile și trăsăturile sale ereditare. Aceste gene pot influența aspectul fizic, comportamentul și alte caracteristici ale organismului. Prin urmare, genotipul este responsabil pentru transmiterea informației genetice de la o generație la alta.

Variabilitatea reprezintă capacitatea organismelor care aparțin aceleiași specii de a se diferenția sau de a se deosebi unele de altele. Aceasta se referă la diferențele în caracteristici fizice, comportamentale sau genetice între indivizii aceleiași specii. Prin variabilitate, organisme ale aceleiași specii pot avea trăsături diferite și pot adapta la medii diferite.

In a monohybrid cross, where two organisms with different alleles for a single trait are crossed, the F2 generation will have a genotype ratio of 1:2:1. This means that 25% of the organisms will be homozygous dominant, 50% will be heterozygous, and 25% will be homozygous recessive. Therefore, the correct answer is 50%, as it represents the percentage of organisms that will be homozygous in the F2 generation.

Crossing-over-ul reprezintă schimbul reciproc de gene între cromozomii omologi. Wile the other options mentioned in the question are not accurate explanations for crossing-over, the correct answer correctly states that crossing-over involves the reciprocal exchange of genes between homologous chromosomes. This process occurs during meiosis and contributes to genetic variation by creating new combinations of alleles on the chromosomes.

The correct answer is "genelor unui organism." The term "genotip" refers to the complete set of genes present in an organism. It represents the genetic makeup of an individual and includes all the genes that determine the traits and characteristics of that organism. Therefore, the correct answer is the entirety of the genes in an organism.

Mendel a enunţat legea puritatăţii gameţilor pe baza experienţelor sale de încrucişare la mazăre. Această lege afirmă că genele purtate de un organism sunt separate în gameţi în timpul formării acestora, astfel încât fiecare gamet conţine doar o copie a fiecărei gene. Astfel, în momentul încrucişării, genele se combină aleatoriu, iar descendenţii obţinuţi vor avea o combinaţie nouă de gene. Această lege a purităţii gameţilor este esenţială pentru înţelegerea eredităţii şi a modului în care trăsăturile sunt transmise de la o generaţie la alta.

Un organism cu genotipul AABB este pur din punct de vedere genetic deoarece are două alele identice pentru fiecare genă. Acest lucru înseamnă că toți descendenții săi vor avea aceleași alele pentru acele gene.

This answer is correct because it refers to the principle of independent assortment, which is one of Mendel's laws of inheritance. This principle states that the alleles for different traits segregate independently of one another during the formation of gametes. In other words, the inheritance of one trait does not affect the inheritance of another trait. This principle is based on the random alignment and separation of homologous chromosomes during meiosis.

Un individ cu genotipul AaBB formează două tipuri de gameți AB și aB. Aceasta se datorează faptului că individul are două alele diferite pentru gena A (A și a) și două alele identice pentru gena B (B și B). În procesul de formare a gameților, aceste alele se separă și se combină în toate combinațiile posibile, rezultând două tipuri de gameți: AB și aB. Aceasta este o caracteristică a segregării independente a genelor în timpul formării gameților.

The correct answer is "are loc în timpul profazei I meiotice." This is because the reciprocal exchange of chromatid segments, also known as crossing over, occurs during prophase I of meiosis. This process involves the exchange of genetic material between homologous chromosomes, leading to genetic variation in offspring.

The correct answer is "perechile de factorii ereditari segregă independent unele de altele" which translates to "the pairs of hereditary factors segregate independently of each other." This means that during the formation of gametes, the alleles for different traits segregate independently and are randomly assorted into the gametes. This discovery by Mendel is known as the principle of independent assortment and is one of the fundamental principles of genetics. It explains how different traits are inherited independently of each other and allows for the variation and diversity seen in offspring.

When crossing AaBB with aaBb, the genotype of the first parent is AaBB and the genotype of the second parent is aaBb. In this case, the capital letters represent dominant alleles and the lowercase letters represent recessive alleles. The genotype aaBb can produce two types of gametes: aB and ab. The genotype AaBB can only produce one type of gamete: AB. Therefore, when these two genotypes are crossed, the possible genotypes of the offspring are AaBb and Aabb, with equal probabilities. Since the question asks for the proportion of offspring with the genotype aaBb, which is only one out of the four possible genotypes, the answer is 1/4.

The correct answer is "iepurele parinte cu blana cenusie este homozigot". This means that the parent rabbit with gray fur has two identical alleles for the gray fur trait. This is supported by the fact that when this gray-furred rabbit is crossed with a white-furred rabbit, only gray-furred offspring are produced. If the gray fur gene was heterozygous, there would be a chance for white-furred offspring as well. Therefore, the conclusion that the gray-furred parent rabbit is homozygous for the gray fur trait is correct.

In birds, males do not have heterosomes, while females have two heterosomes, X and Y. This means that females have a pair of sex chromosomes, one X and one Y, while males have two of the same sex chromosomes, either two X or two Y.

Inheritance refers to the passing down of traits from parents to offspring. In this context, the correct answer states that inheritance involves the descendants inheriting traits that are appropriate for their species. This means that offspring inherit characteristics that are typical for their species, such as eye color or hair type. This process of inheriting traits is a fundamental mechanism in genetics and plays a crucial role in the variation and evolution of species.

In a monohybrid cross, the F2 generation will result in organisms that are heterozygous in a ratio of 50%. This means that half of the offspring will have two different alleles for the trait being studied, while the other half will have two identical alleles. This is due to the random assortment of alleles during gamete formation and the equal chance of each allele being passed on to the offspring. Therefore, the correct answer is 50%.

The correct answer is "poate fi homozigot sau heterozigot". This means that a dominant trait can be expressed in an organism whether it is homozygous (carrying two copies of the dominant allele) or heterozygous (carrying one copy of the dominant allele and one copy of the recessive allele). It is not necessary for the trait to skip a generation or only be expressed in a homozygous state.

An individual homozygous for a certain trait means that they have two identical alleles for that trait, either two dominant alleles or two recessive alleles. This individual does not have both the dominant and recessive alleles for the trait. Having two dominant or two recessive alleles in a pair is what defines homozygosity.

Gregor Mendel experimented with hybridization in self-pollinating plants. He conducted extensive studies on pea plants and observed the segregation of traits in the offspring. Through his experiments, Mendel discovered the principles of inheritance and formulated the laws of genetics, including the law of segregation and the law of independent assortment. His work laid the foundation for modern genetics and our understanding of how traits are passed down from one generation to the next.

Hibrizii care rezultă din încrucișarea AA x aa manifestă caracterul dominant. This means that the offspring will exhibit the trait that is dominant in the parent with genotype AA.

When two pea plants with smooth seeds are crossed, one being homozygous and the other being heterozygous, the resulting plants will only have smooth seeds. This is because the homozygous plant will only contribute smooth alleles to the offspring, while the heterozygous plant will contribute both smooth and wrinkled alleles. However, the smooth allele is dominant over the wrinkled allele, so all the offspring will have smooth seeds.

When two heterozygous parents mate, they each carry one dominant allele and one recessive allele for a particular trait. The dominant allele is expressed in the phenotype, while the recessive allele is not. When these parents reproduce, there is a 50% chance that their offspring will inherit the dominant allele from both parents, making them homozygous for the dominant trait. This means that they will express the dominant trait in their phenotype. Therefore, the statement "au 50% descendenţi homozigoţi" is correct.

The correct answer is "este moştenit de la ambii părinţi" which means "it is inherited from both parents." This is the explanation for the correct answer.