Answer:
<h2>RrYy and rryy
</h2>
Explanation:
1. As given; Round seeds (R) are dominant on wrinkled seeds (r),
Yellow seeds (Y) are dominant on green seeds (g).
In a testcross, between an unknown genotype and a homozygous recessive with wrinkled and green seeds (rryy).
offspring are:
Round and yellow are 53; genotype (R_Y_)
round and green are 49; genotype (R_yy)
wrinkle and yellow are 44; genotype (rrY_)
wrinkled and green are 51 ; genotype (rryy)
Here, the genotype of parents of these offspring would be RrYy and rryy.
Answer:
extinction and change in species competition.
Explanation:
Answer:
To make a positive change in the environment.
Explanation:
We have to Stimulate birds with 3 different beaks by feeding them fruit to stimulate a positive change in the environment because birds control insect and rodent in the environment that causes severe damage to crops. It also contributes to pollination, and seed dispersal which result in great benefits to people. Annually insects destroy hundreds of millions of dollars of agricultural and forest products so if we provide safe environment to the birds they can save our millions of dollars.
Answer:
AaBb × aabb
Explanation:
A test cross is a cross between an unknown genotype (dominant phenotype) with a homozygous recessive genotype in order to discover the actual genotype of the species exhibiting dominant phenotype.
This is because one allele of a gene is capable of masking the expression of another, the allele masking is called DOMINANT allele while the allele being masked is called RECESSIVE allele. The combination of these two alleles is termed heterozygosity.
An organism that is phenotypically dominant for a specific trait may either be heterozygous or homozygous for that gene. For example, a plant gene for tallness with an dominant allele T, and recessive allele t. This plant will need tall if the genotype is TT (homozygous dominant) or Tt (heterozygous dominant). In order to know which of these genotypes the plant actually has, a test cross is conducted.
In this example, two genes A and B are involved. For the first gene, A represents dominant allele while a represents recessive allele. For the second gene, B represents dominant allele while b represents recessive allele.
In a cross involving parents AABB (homozygous dominant for both genes) and aabb (homozygous recessive for both genes), the F1 progeny will all exhibit phenotypic dominance (AaBb).
However, we cannot know the genotype by merely looking at the phenotype. We cannot ascertain yet whether the dominance is heterozygous or homozygous, hence the need for a test cross.
The test cross is between the dominant F1 progeny and a homozygous recessive i.e. AaBb × aabb. Some of the F2 generation will show recessive traits if the unknown genotype is heterozygous.
