Genetică Umană

Sindromul Down este provocat de modificarea numărului de cromozomi. Aceasta se referă la prezența unui cromozom suplimentar în celulele organismului, în special în cromozomul 21. Această modificare genetică cauzează o serie de caracteristici fizice distinctive și poate afecta dezvoltarea intelectuală și fizică a individului. Sindromul Down nu este o maladie metabolică ereditară și nu are nicio legătură cu incapacitatea de a distinge culorile sau cu albinismul.

This statement is true because individuals with blood type A can have two possible genotypes: AA (homozygous) or AO (heterozygous). Homozygotes have two identical alleles for blood type A, while heterozygotes have one allele for blood type A and one allele for blood type O. Therefore, individuals with blood type A can be either homozygous or heterozygous.

The correct answer is ♀XX and ♂XY. This is because in a healthy human, females have two X chromosomes (♀XX) and males have one X and one Y chromosome (♂XY). This combination of chromosomes determines the individual's sex.

Sindromul Down este reprezentat de trisomia 21. Acesta este un defect genetic în care persoana afectată are o copie suplimentară a cromozomului 21. Această anomalie cromozomială cauzează o serie de caracteristici fizice distinctive și poate afecta dezvoltarea cognitivă și fizică a individului. Trisomia 18, trisomia 13 și trisomia 22 sunt alte anomalii cromozomiale, dar nu sunt asociate cu sindromul Down.

The statement suggests that Down syndrome is caused by polyploidy. However, this is not true. Down syndrome is actually caused by the presence of an extra copy of chromosome 21, a condition known as trisomy 21. Polyploidy refers to the presence of multiple sets of chromosomes, which is not the cause of Down syndrome. Therefore, the correct answer is False.

The correct answer is AB (IV). The phenomenon of codominance occurs in the case of blood type AB, where both the A and B antigens are present on the red blood cells. This means that individuals with blood type AB have inherited both the A and B alleles from their parents, resulting in the expression of both antigens on their red blood cells. Therefore, blood type AB exhibits codominance, as both alleles are equally expressed.

The descendants of a family where the mother has blood group A (II) homozygous and the father has blood group O (I) can have blood group A (II). This is because the mother has two copies of the A allele, which she can pass on to her children. The father, on the other hand, has two copies of the O allele, which does not contribute any antigens to the blood type. Therefore, the children can inherit one A allele from the mother and one O allele from the father, resulting in blood group A.

The correct answer is "apare din cauza unui cromozom suplimentar." This means that Down Syndrome occurs due to an extra chromosome. In individuals with Down Syndrome, instead of having two copies of chromosome 21, they have three copies, resulting in a total of 47 chromosomes instead of the usual 46. This extra chromosome causes the characteristic physical and developmental features associated with Down Syndrome.

Hemofilia se caracterizează prin absența factorilor de coagulare din plasmă. Aceasta înseamnă că persoanele cu hemofilie au o deficiență sau lipsă a acestor factori, ceea ce duce la o coagulare defectuoasă a sângelui. Acest lucru poate cauza sângerări excesive și dificultate în oprirea sângerării.

The statement suggests that individuals with blood type O(I) can be either homozygous or heterozygous. However, this is incorrect. Blood type O is a recessive trait, meaning that individuals with blood type O must be homozygous for the O allele. Therefore, individuals with blood type O(I) can only be homozygous, not heterozygous.

The given statement is false because if both parents have blood type B (III) and are heterozygous, there is a possibility for their children to have blood type O (I). This is because both parents can pass on the O allele to their children, resulting in the children having blood type O.

The correct answer is "sindromul Down". Sindromul Down, also known as Down syndrome, is a chromosomal disorder caused by the presence of an extra copy of chromosome 21. It is a genetic condition that leads to physical and intellectual disabilities. Individuals with Down syndrome typically have characteristic facial features, developmental delays, and may also experience other health issues such as heart defects and hearing problems.

The given statement is true. Down syndrome is caused by an aneuploidy, which means there is an abnormal number of chromosomes in the cells. In the case of Down syndrome, there is an extra copy of chromosome 21, resulting in a total of three copies instead of the usual two. This extra genetic material leads to the characteristic physical features and developmental challenges associated with Down syndrome.

The correct answer is Sindromul Down. This is a condition caused by the presence of an extra copy of chromosome 21 in a person's cells. It is characterized by intellectual disability, distinct facial features, and often other health issues such as heart defects or digestive problems. It is the most common chromosomal disorder and occurs in about 1 in every 700 births.

Hemofilia is a genetic disorder that is inherited in a recessive manner and is located on the sex chromosomes, specifically the X chromosome. This means that the gene responsible for hemophilia is carried on the X chromosome, and in order for a person to have the disorder, they must inherit the faulty gene from both of their parents. Hemophilia is characterized by a deficiency or absence of certain blood clotting factors, leading to prolonged and excessive bleeding.

The correct answer is "Sindromul Turner". This is because Turner syndrome is a condition in which a female is born with only one X chromosome, instead of the usual two. This condition can lead to various physical and developmental abnormalities, such as short stature, infertility, and heart defects. It is considered a heterozygous monosomy because it involves the loss of one chromosome from a pair.

Maladiile genice sunt provocate de mutaţii ale genelor. Aceasta înseamnă că modificările sau mutațiile în secvența de ADN a genelor pot duce la apariția unor afecțiuni genetice. Aceste mutații pot afecta producția sau funcționarea proteinelor, care sunt responsabile de diverse procese biologice în organism. Astfel, mutațiile genetice pot cauza maladii ereditare sau dobândite, care pot afecta diferite sisteme sau organe din corpul uman.

The given statement is false. "Cri-du-chat" syndrome is caused by a deletion of a portion of chromosome 5, not by a numerical aberration of the sex chromosomes.

Hemophilia is a genetic disorder that is caused by a mutation in a heterozygous gene. This means that the gene responsible for hemophilia is located on one of the sex chromosomes, usually the X chromosome. Because males have only one X chromosome, if they inherit the mutated gene, they will be affected by hemophilia. Females, on the other hand, have two X chromosomes, so even if they inherit the mutated gene, they have a second healthy copy that can compensate for the mutation. Therefore, hemophilia predominantly affects males.

Albinismul este o boală genetică autozomală recesivă. Aceasta înseamnă că boala se transmite prin intermediul unui singur cromozom ne-sexual și că persoana afectată trebuie să primească două copii ale genei defecte (una de la fiecare părinte) pentru a dezvolta boala. Albinismul este caracterizat prin absența totală sau parțială a pigmentului în piele, păr și ochi, ceea ce duce la o sensibilitate crescută la lumina solară și la probleme de vedere.

The correct answer is "determinată de o genă autozomală recesivă." This means that albinism is caused by a recessive gene on an autosome (a non-sex chromosome). In order for a person to have albinism, they must inherit two copies of the recessive gene, one from each parent. If they only inherit one copy, they will be a carrier of the gene but will not have albinism themselves.

The correct answer is "reprezintă o monosomie" which means "represents a monosomy" in English. Monosomy refers to a genetic condition where an individual has only one copy of a particular chromosome instead of the usual two copies. In the case of Turner syndrome, it is caused by the absence of one X chromosome in females, resulting in a monosomy of the sex chromosomes (45,X). This condition can lead to various physical and developmental abnormalities.

The correct answer is "se transmite băieţilor pe linie maternă" which means "it is transmitted to boys through the maternal line". This means that the condition is passed down from a carrier mother to her sons, as the gene responsible for hemophilia is located on the X chromosome. Daughters of carrier mothers have a 50% chance of inheriting the gene and being carriers themselves, while sons have a 50% chance of inheriting the gene and having hemophilia.

Polidactilia este o maladie genică autozomală dominantă, ceea ce înseamnă că o singură copie a genei defecte este suficientă pentru a dezvolta boala. Polidactilia se caracterizează prin prezența unui număr anormal de degete la mâini sau picioare. În acest caz, polidactilia este corect identificată ca fiind o maladie genică autozomală dominantă.

Daltonismul este o maladie genică heterozomală recesivă. Acest termen se referă la o tulburare a vederii în care indivizii nu pot distinge culorile în mod normal. Aceasta este cauzată de o mutație genetică recesivă pe cromozomul X. Persoanele afectate de daltonism au dificultăți în a distinge între anumite culori, în special între roșu și verde. Albinismul, polidactilia și sindactilia nu sunt exemple de maladii genice heterozomale recesive și, prin urmare, nu sunt răspunsul corect la întrebare.

Anemia falciformă la om apare din cauza unei mutaţii genice autozomale. This means that the condition of sickle cell anemia in humans is caused by a mutation in a gene that is located on an autosome (non-sex chromosome). The mutation affects the shape of red blood cells, causing them to become sickle-shaped. This mutation is inherited in an autosomal recessive manner, meaning that an individual needs to inherit two copies of the mutated gene (one from each parent) in order to develop the condition.

The correct answer is XX and XhY. This is because in the question it is mentioned that all male descendants are healthy, which means they do not have the gene for hemophilia. Therefore, the father must have a normal X chromosome (XX) and a Y chromosome (XY). On the other hand, all female descendants are healthy but carriers of the gene for hemophilia. This means that they have one normal X chromosome (XX) and one X chromosome with the gene for hemophilia (Xh). Therefore, the genotypes of the parents are XX and XhY.

The correct answer is "mutaţii genomice". This is because trisomy refers to a genetic disorder where there is an extra copy of a chromosome, rather than a specific gene mutation. Genomic mutations involve changes in the structure or number of chromosomes, which is consistent with trisomy. Therefore, "mutaţii genomice" is the most appropriate answer in this context.