Species-specific sperm attraction has been documented in numerous species. In echinoderms, sperm are attracted toward eggs of their species by chemotaxis. Following statements are about chemoattraction-

A. In this process Sperm follows a gradient of a chemical secreted by the egg.

B. These oocytes control only the type of sperm they attract, but not the time at which they attract them.

C. Releasing the chemotactic factor only when the sea urchin egg has completed all of its meiotic divisions .

D. Releasing the chemotactic factor only when the sea urchin egg is in second metaphase of its meiotic division.

E. The mechanisms of chemotaxis differ among species and chemotactic molecules are different even in closely related species.

Which of the following statement are incorrect about this process?

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#Question id: 4918

#Unit 8. Inheritance Biology

The two organelles responsible for cytoplasmic inheritance among eukaryotes are

TLS Online TPP Program

#Question id: 4919

#Unit 8. Inheritance Biology

Genes for cytoplasmic male sterility in plants are generally located in

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#Question id: 4928

#Unit 8. Inheritance Biology

A certain kind of snail can have a right-handed direction of shell coiling (D) or left handed coiling (d). If direction of coiling is due to a protein deposited by the mother in the egg cytoplasm, then a Dd egg-producing snail and a dd sperm-producing snail will have offspring of which genotype(s) and phenotype(s)?

TLS Online TPP Program

#Question id: 4929

#Unit 8. Inheritance Biology

Maternal inheritance of coiling of shell in snail (limnaea peregra) is well established. The dextral coiling depends on dominant allele D and sinistral coiling depends upon recessive allele d. A female F1 progeny of dextral(Dd) type is crossed with a male dextral (Dd). What will be the phenotype ratio in progeny?

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#Question id: 12703

#Unit 8. Inheritance Biology

In the plants, due to mutation in the mitochondrial genome causing cytoplasmic male sterility can be influenced by the nuclear gene (Rf),  which is dominant over the cytoplasmic mitochondrial genome. If a male sterile plant  is pollinated by the fertile male plant with homozygous (Rf)condition, the progeny obtained in F1 will have

TLS Online TPP Program

#Question id: 12705

#Unit 8. Inheritance Biology

In Neurospora crasssa, the mutant exhibit poky phenotype, when a female of  poky strain is crossed with a normal strain acting as a male , all progeny individuals shows poky phenotype . however, the reciprocal cross resulted in all normal progeny. These results can be explained on the basis of