Exam (elaborations)
BIOL 1404 UPDATED 2024/2025 MIDTERM EXAM |VERIFIED 100% GUARANTEED A+
- Course
- BIO 1404
- Institution
- University Of Texas - San Antonio
BIOL 1404 UPDATED 2024/2025 MIDTERM EXAM |VERIFIED 100% GUARANTEED A+
[Show more]
Content preview
BIOL 1404 UPDATED 2024/2025 MIDTERM EXAM |VERIFIED100% GUARANTEED A+
1) Males are more often affected by sex-linked traits than females because
A) male hormones such as testerone often alter the affects of mutations on the X chromosome.
B) female hormones such as estrogen often compensate for the effects of mutations on the X
chromosome.
C) X chromosomes in males generally have more mutations than X chromosomes in females.
D) males are hemizygous for the X chromosome.
E) mutations on the Y chromosome often worsen the effects of X-linked mutations.
2) In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color.
The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black
female and an orange male?
A) tortoiseshell females; tortoiseshell males
B) black females; orange males
C) orange females; orange males
D) tortoiseshell females; black males
E) orange females; black males
3) Cinnabar eyes is a sex-linked recessive characteristic in fruit flies. If a female having cinnabar eyes is
crossed with a wild-type male, what percentage of the F1 males will have cinnabar eyes?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%
4) In humans, clear gender differentiation occurs not at fertilization, but after the second month of gestation.
What is the first event of this differentiation?
A) formation of testosterone in male embryos
B) formation of estrogens in female embryos
C) anatomical differentiation of a penis in male embryos
D) activation of SRY in male embryos and masculinization of the gonads
E) activation of SRY in females and feminization of the gonads
5) All female mammals have one active X chromosome per cell instead of two. What causes this?
A) activation of the XIST gene on the X chromosome that will become the Barr body
B) activation of the BARR gene on one X chromosome, which then becomes inactive
C) crossing over between the XIST gene on one X chromosome and a related gene on an autosome
, D) inactivation of the XIST gene on the X chromosome derived from the male parent
E) attachment of methyl (CH3) groups to the X chromosome that will remain active:
6) How would one explain a testcross involving F1 dihybrid flies in which more parental-type offspring
than recombinant-type offspring are produced?
A) The two genes are closely linked on the same chromosome.
B) The two genes are linked but on different chromosomes.
C) Recombination did not occur in the cell during meiosis.
D) The testcross was improperly performed.
E) Both of the characters are controlled by more than one gene.
7) What does a frequency of recombination of 50% indicate?
A) The two genes are likely to be located on different chromosomes.
B) All of the offspring have combinations of traits that match one of the two parents.
C) The genes are located on sex chromosomes.
D) Abnormal meiosis has occurred.
E) Independent assortment is hindered
8) Recombination between linked genes comes about for what reason?
A) Mutation on one homolog is different from that on the other homolog.
B) Independent assortment sometimes fails because Mendel had not calculated appropriately.
C) When genes are linked they always "travel" together at anaphase.
D) Crossovers between these genes result in chromosomal exchange.
E) Nonrecombinant chromosomes break and then re-join with one another
9) Why does recombination between linked genes continue to occur?
A) Recombination is a requirement for independent assortment.
B) Recombination must occur or genes will not assort independently.
C) New allele combinations are acted upon by natural selection.
D) The forces on the cell during meiosis II always result in recombination.
E) Without recombination there would be an insufficient number of gametes
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Edumaxsolutions. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
50155 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now