Question

The proteins that hold homologous chromosomes after replication are called

Select one:

a. Kinetochores

b. Homologous chromosomes are NOT held together after replication!

c. Centromeres

d. Cohesins

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The ratio of a testcross between an organism with unknown genotype and its homozygous recessive counterpart is 1:1 (same number of heterozygous and homozygous recessive offsprings). Based on this ratio, what can you deduce about the genotype of the unknown organism?

Select one:

a. The unknown organism is homozygous dominant

b. There is no way to tell from the information given. There could be many possibilities

c. The unknown organism is heterozygous

d. The unknown organism is homozygous recessive

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Transcription factors tend to bind to DNA at the level of the major grooves

Select one:

a. True

b. False

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Typically, the longest phase of the cell cycle is

Select one:

a. Prophase

b. The G1 phase

c. The G2 phase

d. The S phase

e. Metaphase

f. Anaphase

g. Telophase

Answer 1

1. Homologous chromosomes replicate and form four arms of sister chromatids and they are held together by centromeres. Hence the answer is centromere.

2. The test cross is performed and the offspring genotype is 1:1 which means that the unknown genotype is a heterozygous individual because if it was a homozygous individual then all the offsprings would be identical. Hence the correct option is c. The unknown organism is heterozygous

3. The proteins that alter the DNA functions are always bind to the major groove of DNA. Hence the transcription factors which are also protein molecules bind to the major groove of DNA. hence the statement is True.

4. In cell cycle the longest phase of cell cycle is the G1 phase where the protein required for replication of DNA are made and also other protein are made. Henne the correct answer is G1 phase.

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