click below
click below
Normal Size Small Size show me how
MCQ genetics test
AP Bio MCQ for genetics/heredity test
Question | Answer |
---|---|
Meiosis begins with a normal (___) cell with a ___ number (2n) of chromosomes. | somatic, diploid |
Under normal conditions, the cell's chromosome number will become ___ (n) towards the end of telophase in Meiosis 1 (the first half of meiosis) while on its way to form gametes. | haploid |
The diploid number would be restored during ___ when one gamete (sperm) unites with another gamete (egg) [at random (genetic variation] | Fertilization |
If the statement in #1 is applied to a mosquito, with a diploid number of 6 chromosomes per somatic cell, then its gametes would each contain ___ chromosomes | 3 |
Don't forget about the other phases of the cell cycle, when the cell isn't dividing. Although chromosomes do get ___ during the S phase, the chromosome number doesn't change as a result of the S phase. | duplicated |
One very important consequence is the reduction of the chromosome number by half when the gametes are produced. What problem would occur if this didn't happen? | The next generation would get too many chromosomes |
When homologous chromosomes are separated during ___, by spindle microtubules, we can actually see the reduction in action. | Anaphase 1 |
Don't forget the key events during meiosis which contribute to genetic variation including the ___ of homologous chromosomes during ___ | crossing over, prophase 1 |
Many genetics studies have shown that two different traits on the same chromosome will have an ___ rate of crossing over if they are further apart | increased |
Another key event during meiosis that contributes to genetic variation is the __ __ of homologous chromosomes along the metaphase plate, supporting Mendel's 2nd law: ___ assortment of chromosomes into the gametes. Leading to more genetic ___ in population | random alignment, independent, variation |
Some types of genes result in death of an offspring, also known as ___ | lethal |
If two heterozygous individuals have offspring, what are the chances of them having a heterozygous offspring? (also uses punnett square) | 50% |
In a pedigree showing a sex-linked recessive trait, you'll see more ___ affected. If a trait is not sex-linked, we say that it is ___ | males, autosomal |
In some cases, two different types of genes, also known as ___, can function better at two different temperatures. | alleles |
individ. who are homo. for an Allele A enzyme could metabolize glucose better at 28 dC, while individ. who are homo. for an Allele B enzyme could do better at 22 dC. What's the explanation for individ. who metabolized glucose efficiently for BOTH temp.? | This individual could be heterozygous for a codominant trait |
A unique chromosomal situation in which a person with XXY syndrome was hetero. for color blindness. Please use X^b to indicate color blindness, and write down their complete genotype indicating color blindness. What's the physical gender/phenotypes | X^BX^bY, male (The Y is still active), normal vision, carrier of color blindness gene |
When someone gets a third copy of a chromosome in their cells, it's a result of a process called ___. This can possibly occur in sperm generation ___ in males or in egg generation ___ in females | nondisjunction, spermatogenesis, oogenesis |
Autosomal dominant pedigree | one or both parents are affected, many children are affected in both genders, all siblings linked together, mom- homozygous, dad- heterozygous |
Autosomal recessive pedigree | possible neither parent is affected but child is affected, few children are affected in both genders, siblings linked, mom-heterozygous, dad- heterozygous, affected child- homozygous |
sex-linked recessive pedigree | trait primarily expressed in males, can tend to skip generations from grandfather to grandson, male- X^TY/X^tY, mom- X^TX^t but can also have unknown genotypes |