Attached earlobes are recessive to free earlobes. what genotypic ratio is expected when an individual with attached earlobes mates with an individual heterozygous for free earlobes?
a) 2: 1
b) 3: 1
c) 1: 1
d) 1: 2: 1

C

Explanation:

This is a monohybrid cross between involving a gene coding for earlobe. The allele for free earlobe (F) is dominant over that of attached earlobe (f).

N.B: let F represent the gene involved.

A genotypic ratio is the ratio derived from the offsprings based on the actual genetic make-up and not based on their phenotypic appearance as in phenotypic ratio.

A homozygous individual is an individual having the same kind of alleles for a gene while a heterozygous individual is one that has two different alleles i.e. combination of the dominant and recessive allele.

The monohybrid cross is between an individual with attached earlobe (ff) i.e. homozygous recessive individual. (Note that, a recessive trait will only be expressed in a homozygous state) and a heterozygous free earlobeb individual (Ff). (See attached picture). Ff × ff

The resulting four offsprings will

be expected to have only two distinct genotypes i.e heterozygous (Ff) and homozygous recessive (ff) in an equal ratio i.e. 2:2 ~ 1:1

lysosomes contain a variety of enzymes, enabling the cell to break down various biomolecules it engulfs, including peptides, nucleic acids, carbohydrates, and lipids (lysosomal lipase). the enzymes responsible for this hydrolysis require an acidic environment for optimal activity. hope i !

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.